Graph display device, graph display method, and program

Abstract

To display a plurality of line graphs in an easy-to-see manner.SOLUTION: The graph display device includes a controller configured to determine display colors of a first line graph, a second line graph, and a third line graph based on a comparison result between a first size and a second size, the first size being a size of a section in which the second line graph intersects with the first line graph, the second size being a size of a section in which the third line graph intersects with the first line graph, when a graph image including the first line graph and the second and third line graphs intersecting with the first line graph is displayed on a display unit, and the first line graph and at least one of the second line graph and the third line graph are displayed in different display colors.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a graph display device, a graph display method, and a program. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known a technique for displaying a plurality of line graphs superimposed on a common coordinate plane using a display device (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7249976 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a plurality of line graphs are displayed in the same display mode, the problem arises that the plurality of line graphs as a whole become difficult to see.

[0005] The present invention aims to display multiple line graphs in an easy-to-read manner. [Means for solving the problem]

[0006] In order to solve the above problems, the graph display device according to the present invention comprises: When a graph image including a first line graph and a second line graph and a third line graph that intersect with the first line graph is displayed on a display unit, and when the display color of the first line graph is made different from the display color of at least one of the second line graph and the third line graph, the device includes a control unit that determines the display colors of the first line graph, the second line graph, and the third line graph based on a comparison result between a first size, which is the size of the section where the second line graph intersects with the first line graph, and a second size, which is the size of the section where the third line graph intersects with the first line graph. [Effects of the Invention]

[0007] According to the present invention, a plurality of line graphs can be displayed in an easy-to-read manner. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the configuration of a scientific calculator. [Figure 2] FIG. 2 is a block diagram showing the functional configuration of a scientific calculator. [Figure 3] FIG. 10 is a diagram showing an example of a graph image including multiple line graphs. [Figure 4] FIG. 10 is a diagram showing an intersection section between the graph area of ​​the first line graph and the graph area of ​​the second line graph. [Figure 5] FIG. 10 is a diagram showing an intersection section between the graph area of ​​the first line graph and the graph area of ​​the third line graph. [Figure 6] FIG. 10 is a diagram illustrating a method for deriving an overlap size. [Figure 7] 10 is a flowchart showing a control procedure for an overlap size derivation process. [Figure 8] FIG. 10 is a diagram showing the result of deriving the overlap size. [Figure 9] 10 is a flowchart showing a control procedure for color-coding processing. [Figure 10] 10 is a flowchart showing another control procedure for the color-coding process. [Figure 11] 10 is a flowchart showing another control procedure for the color-coding process. [Figure 12] 12 is a diagram showing a graph image including a plurality of line graphs color-coded by the color-coding process of FIG. 11. FIG. [Figure 13] FIG. 10 is a diagram showing the result of deriving the overlap size. [Figure 14] FIG. 10 shows the results of color coding of a line graph. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will now be described with reference to the drawings. As shown in FIG. 1, scientific calculator 1 (graph display device) includes a housing 10, a key input unit 14, and a display unit 15 provided on housing 10. Scientific calculator 1 can display an input formula and its calculation results, etc. on display unit 15 in response to a user's input operation on key input unit 14. Scientific calculator 1 can also display a line graph representing a function pre-registered by the user, as well as information such as analysis results related to the line graph, on display unit 15. As shown in FIG. 2, scientific calculator 1 includes, in addition to key input unit 14 and display unit 15, a CPU 11 (Central Processing Unit) (control unit, control means), a RAM 12 (Random Access Memory), and a storage unit 13. The components of scientific calculator 1 are connected via a data transmission path such as a bus.

[0010] The CPU 11 is a processor that controls the operation of the scientific calculator 1 by reading and executing a program 131 stored in the storage unit 13 and performing various arithmetic operations. The CPU 11 functions as a control unit by executing the program 131 and performing various operations. For example, when a key on the key input unit 14 is pressed, the CPU 11 executes a process corresponding to a function pre-assigned to the pressed key and causes the display unit 15 to display an indication of the pressed key and the calculation result corresponding to the operation. The scientific calculator 1 may have multiple processors (e.g., multiple CPUs), and the multiple processes performed by the CPU 11 in this embodiment may be executed by these multiple processors. In this case, the multiple processors constitute a control unit. In this case, the multiple processors may be involved in a common process, or the multiple processors may independently execute different processes in parallel. The RAM 12 provides a working memory space for the CPU 11 and stores temporary data. The RAM 12 temporarily stores display image data 121 generated by the CPU 11 to display an image on the display unit 15, various calculation results by the CPU 11, and the like. These data may be stored in the storage unit 13. The storage unit 13 is a non-transitory recording medium readable by the CPU 11 as a computer, and stores the program 131 and various data. The storage unit 13 includes a non-volatile memory such as a flash memory. The program 131 is stored in the storage unit 13 in the form of a program code readable by the computer. The storage unit 13 also stores information on functions registered by the user, etc.

[0011] 1, the key input unit 14 has a plurality of keys that are operated (pressed) by the user. The plurality of keys include numeric keys, operation keys for executing operations such as addition, subtraction, multiplication, and division, symbol keys for inputting function symbols, an AC key for clearing all operation results, a decision key for inputting a decision, direction keys for inputting up, down, left, and right directions, and tool keys for calling various functions. When each key is operated, the key input unit 14 outputs operation information corresponding to the operated key to the CPU 11.

[0012] The display unit 15 includes a liquid crystal display and a drive circuit (not shown) for driving the liquid crystal display. Various displays are performed on the liquid crystal display in accordance with display control signals and display image data 121 output from the CPU 11 to the drive circuit. The liquid crystal display of the display unit 15 can display a predetermined number of colors at each pixel arranged in a matrix. Each pixel has red, green, and blue color filters, pixel electrodes provided at positions corresponding to the color filters, and a liquid crystal layer provided between the pixel electrodes and a counter electrode. The liquid crystal display adjusts the transmittance of red, green, and blue light at each pixel by changing the orientation state of the liquid crystal layer in accordance with the magnitude of the voltage applied to each pixel electrode, thereby achieving color display. The liquid crystal display of this embodiment has 216 vertical pixels and approximately 384 horizontal pixels, but the number of pixels is not limited to this.

[0013] Next, the operation of the scientific calculator 1 will be described, focusing on the operation of displaying a line graph. The CPU 11 of the scientific calculator 1 executes a graph application included in the program 131 to display a graph image 20 as shown in FIG. 3 in the display area 151 of the display unit 15. The graph image 20 in FIG. 3 includes a predetermined range on a coordinate plane, an X-axis (first coordinate axis) and a Y-axis (second coordinate axis) that are the coordinate axes of the coordinate plane, and a first line graph G1, a second line graph G2, and a third line graph G3 that represent three functions registered in advance by the user. Hereinafter, these three line graphs will be collectively referred to as "line graphs G1 to G3," and any one of the line graphs G1 to G3 will be referred to as "line graph G." The CPU 11 generates display image data 121 for such graph image 20 and causes the display unit 15 to perform a display operation based on the display image data 121, thereby displaying the graph image 20 in the display area 151. 3, the first line graph G1 and the second line graph G2 are cubic curves, and the second line graph G2 is a quadratic curve. Furthermore, within the display area 151, the line graphs G1 to G3 intersect with each other.

[0014] If multiple line graphs in a graph image 20 including line graphs that intersect with each other are displayed in the same color, it becomes difficult to distinguish between the line graphs, making the multiple line graphs difficult to see. Therefore, in this embodiment, when at least three line graphs G1 to G3 are included in the graph image 20 and a first line graph G1 intersects with the other line graphs, a second line graph G2 and a third line graph G3, the CPU 11 of the scientific calculator 1 makes the display color of the first line graph G1 different from the display color of at least one of the second line graph G2 and the third line graph G3. For example, in FIG. 3, the CPU 11 makes the display colors of the line graphs G1 to G3 different from each other.

[0015] Specifically, the CPU 11 determines the display colors of the line graphs G1 to G3 based on a comparison result between an overlap size S1 (first size), which is the size of the section where the second line graph G2 intersects with the first line graph G1, and an overlap size S2 (second size), which is the size of the section where the third line graph G3 intersects with the first line graph G1. An overlap size S3 (third size), which is the size of the section where the third line graph G3 intersects with the second line graph G2, may also be used in determining the color. The overlap size S1 is derived based on the distribution of the intersection section C1 (first intersection section) shown in FIG. 4. The intersection section C1 is a section (area) where the graph area RG1 (first graph area) of the first line graph G1 and the graph area RG2 (second graph area) of the second line graph G2 overlap. The graph area RG1 is an area within a predetermined distance from the plot position of the first line graph G1, and the graph area RG2 is an area within a predetermined distance from the plot position of the second line graph G2. The overlap size S2 is derived based on the distribution of the intersection section C2 (second intersection section) shown in FIG. 5. The intersection section C2 is an area (area) where the graph area RG1 of the first line graph G1 and the graph area RG3 of the third line graph G3 overlap. The graph area RG3 is an area within a predetermined distance from the plot position of the third line graph G3. As shown in FIG. 4, the first line graph G1 and the second line graph G2 intersect at an angle closer to parallel than 45 degrees. As shown in FIG. 5, the first line graph G1 and the third line graph G3 intersect at an angle closer to a right angle than 45 degrees. Therefore, the length L1 in the X-axis direction of the intersection section C1 shown in FIG. 4 is longer than the length L2 in the X-axis direction of the intersection section C2 shown in FIG. 5. For example, the overlap sizes S1 and S2 are derived so that they increase as the lengths L1 and L2 of the intersection sections C1 and C2 increase. Hereinafter, any one of the intersection sections C1 and C2 will be referred to as the "intersection C," and any one of the overlap sizes S1 and S2 will be referred to as the "overlap size S."

[0016] The method for deriving the overlap size S1 will be described in more detail with reference to FIG. 6. The upper left, upper right, and lower left diagrams in FIG. 6 are the same portion of the display area 151, and are extracted portions where the first line graph G1 and the second line graph G2 intersect. Each diagram in FIG. 6 represents a rectangular area measuring 5 pixels in the X-axis direction and 10 pixels in the Y-axis direction. The upper left diagram in FIG. 6 is an extracted portion of the graph area RG1 of the first line graph G1, and the upper right diagram is an extracted portion of the graph area RG2 of the second line graph G2. The black pixel P in the upper left diagram in FIG. 6 represents the plot position of the first line graph G1, and the black pixel P in the upper right diagram represents the plot position of the second line graph G2. First, the CPU 11 sets a weight value Vw1 (first weight value) for pixels P within a predetermined distance range from the plot position of the first line graph G1 such that the value decreases as the pixel P becomes farther from the plot position. Furthermore, the CPU 11 sets a weight value Vw2 (second weight value) for pixels P within a predetermined distance range from the plot position of the second line graph G2 so that the value decreases as the pixel P's distance from the plot position increases. Hereinafter, any one of the weight values ​​Vw1 and Vw2 will be referred to as the "weight value Vw." In this embodiment, the CPU 11 sets the weight value Vw for the pixel P at the plot position of the line graph G to "10." The CPU 11 also sets the weight value Vw for the pixel P adjacent vertically (in the Y-axis direction), horizontally (in the X-axis direction), or diagonally to the pixel P at the plot position of the line graph G to "3." The CPU 11 also sets the weight value Vw for the pixel P adjacent vertically, horizontally, or diagonally to the pixel P with a weight value Vw of "3" to "1." The CPU 11 does not set a weight value Vw for the other pixels P (sets the weight value Vw to "0"). A region consisting of pixels P to which a weight value Vw of "1" or greater is set corresponds to the graph region RG1 or RG2. The rule for setting the weight value Vw is not limited to the above, and any rule that satisfies the condition that the weight value Vw becomes smaller as the pixel P becomes farther from the plot position may be used. The rule for setting the weight value Vw may be changeable in response to a user operation.

[0017] Next, as shown in the lower diagram of FIG. 6, for each pixel P in the display area 151 to which both a weight value Vw1 equal to or greater than "1" and a weight value Vw2 equal to or greater than "1" are set, the CPU 11 derives a sum Va1 (first sum) of the weight value Vw1 and the weight value Vw2. The CPU 11 then identifies a first pixel P1 whose derived sum Va1 is equal to or greater than a second threshold. In this embodiment, the second threshold is "3." In the lower diagram of FIG. 6, the first pixel P1 is colored gray, and the pixel P corresponding to the plot position of the first line graph G1 or the second line graph G2 is colored black. The region consisting of the first pixel P1 corresponds to the intersection section C. Note that the second threshold value of "3" is merely an example and can be changed as appropriate. The value of the second threshold may be changeable in response to a user operation.

[0018] The CPU 11 derives the overlap size S1 based on the distribution of the sum values ​​Va1 equal to or greater than the second threshold in the display area 151, i.e., the distribution of the first pixels P1. Specifically, the CPU 11 derives the overlap size S1 as the sum of the sum values ​​Va1 in a section where the first pixels P1 are distributed consecutively in the X-axis direction for a number equal to or greater than the third threshold, and in a section where the first pixels P1 are distributed consecutively in the Y-axis direction for a number equal to or greater than the third threshold. Specifically, the CPU 11 derives the integrated value Vi at a certain position X in the X-axis direction by adding the sum values ​​Va1 equal to or greater than the second threshold in the Y-axis direction. The CPU 11 performs this process for each position X. As shown in the lower diagram of FIG. 6, if the number of pixels L in a section where an integrated value Vi equal to or greater than "1" is derived is equal to or greater than the third threshold, the CPU 11 determines the sum of the integrated values ​​Vi in that section as the overlap size S1. Furthermore, even if the number of pixels L in the X-axis direction is less than the third threshold, if the section in the Y-axis direction in which an integrated value Vi of 1 or greater is derived continues for a period equal to or greater than the third threshold, the CPU 11 adds the integrated value Vi of the section to the overlap size S. The third threshold may be, for example, about 10 pixels, but is not limited to this. The value of the third threshold may be changeable in response to a user operation.

[0019] 6, a method for deriving the overlap size S1 between the first line graph G1 and the second line graph G2 has been described. The overlap size S2 between the first line graph G1 and the third line graph G3, and the overlap size S3 between the second line graph G2 and the third line graph G3 are also derived in a similar manner. When deriving the overlap size S2, the sum Va2 of the weight values ​​Vw1 and Vw2 corresponds to the "second sum." Furthermore, a pixel P whose derived sum Va2 is equal to or greater than the second threshold corresponds to the "second pixel."

[0020] With reference to FIG. 7, the overlap size derivation process executed by the CPU 11 to derive the overlap size S using the above-described method will be described. The CPU 11 executes the overlap size derivation process when displaying a graph image 20 including three or more line graphs G that at least partially intersect. When the overlap size derivation process starts, the CPU 11 plots the line graph G of the function to be displayed on a virtual screen (step S101). The virtual screen is a virtual screen virtually provided in the RAM 12 or the storage unit 13 and has the same number of pixels as the display area 151. Note that the CPU 11 may actually display the contents of the virtual screen in the display area 151 of the display unit 15. The coordinates of the plot position of the line graph G are determined by substituting the value of each X coordinate on the X axis into the function to obtain the Y coordinate. As shown in the upper left and upper right diagrams of FIG. 6, the CPU 11 sets a weight value Vw of "10," "3," or "1" to the pixel P of the graph area RG of each line graph G (step S102). The CPU 11 selects a pair of line graphs Gm and Gn, and assigns "0" to a variable S(Gm, Gn) that represents the overlap size S for the combination of line graphs Gm and Gn (step S103). The CPU 11 also assigns "0" to a variable St that represents the temporary overlap size (step S104). The temporary overlap size St is a variable that temporarily stores a candidate value to be added to the overlap size S(Gm, Gn). The CPU 11 derives an added value Va of the weight values ​​Vw of the line graphs Gm and Gn for each pixel P, as shown in the lower diagram of FIG. 6 (step S105).

[0021] The CPU 11 assigns the minimum X coordinate value Xmin in the display area 151 to a variable X representing a position in the X axis direction (step S106). Hereinafter, the position represented by the variable X will be referred to as "position X." The CPU 11 integrates an added value Va equal to or greater than the second threshold value at the position X in the Y axis direction to derive an integrated value Vi at the position X (step S107). The CPU 11 determines whether the integrated value Vi at the position X is 0 (step S108). If the CPU 11 determines that the integrated value Vi is not 0 ("NO" in step S108), the CPU 11 adds the integrated value Vi to the temporary overlap size St (step S109). The CPU 11 records the coordinates of a pixel P belonging to an intersection section C where the line graphs Gm and Gn intersect (step S110). Here, the pixel P belonging to the intersection section C is a pixel P whose added value Va is equal to or greater than the second threshold value. CPU 11 determines whether position X is the maximum value Xmax of the X coordinate in display area 151 (step S111). If it is determined that position X is Xmax (YES in step S111), CPU 11 shifts the process to step S114, which will be described later. If it is determined that position X is not Xmax (NO in step S111), CPU 11 increments variable X (step S112), returns the process to step S107, and executes steps S107 to S111 for the next position X.

[0022] If it is determined in step S108 that the integrated value Vi at the position X is 0 ("YES" in step S108), the CPU 11 determines whether or not the temporary overlap size St is 0 (step S113). If it is determined that the temporary overlap size St is 0 ("YES" in step S113), the CPU 11 shifts the processing to step S112. If it is determined that the temporary overlap size St is not 0 ("NO" in step S113), or if the process branches to "NO" in step S111, the CPU 11 determines that the intersection section C in the X-axis direction, in which the integrated value Vi is equal to or greater than "1," has ended. Then, the CPU 11 determines whether or not the length of the intersection section C in the X-axis direction or the Y-axis direction is equal to or greater than a third threshold (step S114). Here, if the difference (X-Xs) between the current position X at which the integrated value Vi became 0 and the start position Xs of the intersection section C is greater than a third threshold, the CPU 11 determines that the length of the intersection section C is equal to or greater than the third threshold ("YES" in step S114). The start position Xs is the smallest X coordinate recorded in step S110. Furthermore, even if X-Xs is equal to or less than the third threshold, the CPU 11 determines that the length of the intersection section C is equal to or greater than the third threshold ("YES" in step S114)) if the length of the intersection section C in the Y-axis direction is equal to or greater than the third threshold. The length of the intersection section C in the Y-axis direction is specified from the range of the Y coordinate of the intersection section C recorded in step S110. If the length of the intersection section C is determined to be equal to or greater than the third threshold ("YES" in step S114), the CPU 11 adds the temporary overlap size St to the overlap size S(Gm, Gn) (step S115). When step S115 is completed, or when it is determined that the length of the intersection section C is less than the third threshold value ("NO" in step S114), the CPU 11 resets the temporary overlap size St to 0 (step S116). Also, although not shown in the figure, the CPU 11 deletes (resets) the coordinates of the pixels belonging to the intersection section C that were recorded in step S110.

[0023] Thereafter, the CPU 11 determines whether the position X is Xmax (step S117). If it is determined that the position X is not Xmax ("NO" in step S117), the CPU 11 shifts the process to step S112 and increments the variable X. If it is determined that the position X is Xmax ("YES" in step S117), the CPU 11 determines whether the overlap size S(Gm, Gn) has been derived for all combinations of line graphs G (step S118). If it is determined that there is a combination of line graphs G for which the overlap size S(Gm, Gn) has not been derived ("NO" in step S118), the CPU 11 selects the next combination of line graphs Gm, Gn (step S119) and shifts the process to step S103. If it is determined that the overlap sizes S(Gm, Gn) have been derived for all combinations of line graphs G (YES in step S118), the CPU 11 ends the overlap size derivation process.

[0024] Next, we will explain first to third color-coding methods for color-coding the line graph G based on the derivation result of the overlap size S. Of these, the first and second color-coding methods will be explained using an example in which the line graphs G to be displayed are line graphs G1 to G3, and the overlap size S shown in Figure 8 is derived for a combination of these line graphs G.

[0025] When coloring using the first color-coding method, the CPU 11 executes the color-coding process shown in Fig. 9. When the color-coding process starts, the CPU 11 acquires an overlap size S1 of an intersection section C1 where the first line graph G1 and the second line graph G2 intersect, and an overlap size S2 of an intersection section C2 where the first line graph G1 and the third line graph G3 intersect (step S201). The CPU 11 determines whether the absolute value of the difference between the overlap size S1 and the overlap size S2 is equal to or greater than a first threshold (step S202). If it is determined that the absolute value of the difference between the overlap size S1 and the overlap size S2 is less than the first threshold ("NO" in step S202), the CPU 11 determines the display colors of the line graphs G1 to G3 to be predetermined default colors (step S203). The default colors may be different for each of the line graphs G1 to G3, or may be a common color for some of the line graphs.

[0026] If it is determined that the absolute value of the difference between the overlap size S1 and the overlap size S2 is equal to or greater than the first threshold value ("YES" in step S202), the CPU 11 determines whether the overlap size S2 is greater than the overlap size S1 (step S204). If it is determined that the overlap size S2 is greater than the overlap size S1 ("YES" in step S204), the CPU 11 determines the display colors of the first line graph G1 and the second line graph G2 to be a first color, and determines the display color of the third line graph G3 to be a second color different from the first color (step S205). By color coding in step S205, the first line graph G1 and the third line graph G3, which have large overlap sizes S2 and long intersection sections C, are displayed in different colors, making it easier to distinguish between the line graphs G with long intersection sections C. If it is determined that the overlap size S2 is smaller than the overlap size S1 ("NO" in step S204), the CPU 11 determines the display color of the first line graph G1 and the third line graph G3 to be the first color, and determines the display color of the second line graph G2 to be the second color (step S206). By color-coding in step S206, the first line graph G1 and the second line graph G2, which have a large overlap size S1 and a long intersection section C, are displayed in different colors, making it easier to distinguish between the line graphs G with long intersection sections C. In the example shown in FIG. 8, the difference between the overlap size S1 ("521") and the overlap size S2 ("124") is 397. For example, if the first threshold is "200," the process branches to "YES" in step S202. Furthermore, because the overlap size S2 is smaller than the overlap size S1, the process branches to "NO" in step S204. Therefore, the first line graph G1 and the third line graph G3 are displayed in a first color, and the second line graph G2 is displayed in a second color.

[0027] When any one of steps S203, S205, and S206 is completed, CPU 11 draws line graphs G1 to G3 in the determined display color (step S207). That is, CPU 11 generates display image data 121 of graph image 20 including line graphs G1 to G3 in the determined display color, and causes display unit 15 to perform a display operation based on the display image data 121, thereby displaying graph image 20 in display area 151 of display unit 15. When step S207 is completed, CPU 11 ends the color-coding process.

[0028] When color-coding using the second color-coding method, the CPU 11 executes the color-coding process shown in FIG. 10. The color-coding process of FIG. 10 differs from steps S203 and S204 of the color-coding process of FIG. 9 in steps S303 and S304, but the other steps are the same as the color-coding process of FIG. 9. The differences from the color-coding process of FIG. 9 will be described below. If it is determined that the absolute value of the difference between the overlap size S1 and the overlap size S2 is less than the first threshold ("NO" in step S302), the CPU 11 determines the display color of the first line graph G1 to be a first color, and determines the display colors of the second line graph G2 and the third line graph G3 to be a second color different from the first color (step S203). If the absolute value of the difference between the overlap size S1 and the overlap size S2 is small, the second line graph G2 and the third line graph G3 intersect with the first line graph G1 in a similar manner, and therefore it can be estimated that there is a strong correlation. Therefore, by color coding in step S303, the second line graph G2 and the third line graph G3, which have a strong correlation, are colored the same, making them easier to recognize together and visually differentiating them from the first line graph G1, which has a weak correlation.

[0029] If it is determined that the absolute value of the difference between the overlap size S1 and the overlap size S2 is equal to or greater than the first threshold value ("YES" in step S302), the CPU 11 determines whether the overlap size S2 is smaller than the overlap size S1 (step S304). If it is determined that the overlap size S2 is smaller than the overlap size S1 ("YES" in step S304), the CPU 11 determines the display color of the first line graph G1 and the second line graph G2 to be the first color, and determines the display color of the third line graph G3 to be the second color (step S305). If the overlap size S2 is smaller than the overlap size S1, the first line graph G1 and the second line graph G2 have a long crossing section C, so it can be estimated that they are similar in shape and have a strong correlation. Therefore, by color-coding in step S305, the first line graph G1 and the second line graph G2, which have a strong correlation, are colored the same, making them easier to recognize together and visually distinguishable from the third line graph G3, which has a weak correlation. If it is determined that the overlap size S2 is larger than the overlap size S1 ("NO" in step S304), the CPU 11 determines the display color of the first line graph G1 and the third line graph G3 to be the first color and the display color of the second line graph G2 to be the second color (step S306). By color-coding in step S306, the first line graph G1 and the third line graph G3, which have a strong correlation, are colored the same, making them easier to recognize together and visually distinguishable from the second line graph G2, which has a weak correlation. The subsequent processing is the same as that in FIG. 9. In the example shown in FIG. 8, the process branches to "YES" in step S202 and to "YES" in step S204. Therefore, the first line graph G1 and the second line graph G2 are displayed in a first color, and the third line graph G3 is displayed in a second color.

[0030] When coloring using the third coloring method, the CPU 11 executes the coloring process shown in FIG. 11. The third coloring method will be described using an example in which five line graphs G1 to G5 are drawn in different colors as shown in FIG. 12. The number of colors that can be colored is assumed to be three. When the coloring process starts, the CPU 11 sorts the combinations of line graphs G in descending order of overlap size S, as shown in FIG. 13 (step S401). In the example shown in FIG. 13, the overlap size S(G1, G2) between the first line graph G1 and the second line graph G2 is the largest, followed by the overlap size S(G1, G4) between the first line graph G1 and the fourth line graph G4, and the overlap size S(G2, G4) between the second line graph G2 and the fourth line graph G4. The CPU 11 groups the line graphs G in descending order from the highest to lowest so that the number of line graphs G in one group is the number that can be colored (step S402). 13, the first line graph G1 and the second line graph G2 corresponding to the largest overlap size S and the fourth line graph G4 corresponding to the next largest overlap size S are assigned to one group, and the remaining third line graph G3 and fifth line graph G5 are assigned to another group. The assignment result is as shown in FIG.

[0031] Once the grouping is complete, the CPU 11 identifies the combination of line graphs G within each group that has the largest overlap size S, and determines the display colors of the identified two line graphs G to be two colors that are opposite each other on the color wheel (step S403). For example, among the three line graphs G1, G2, and G4 in group 1 shown in FIG. 14, the combination of the first line graph G1 and the second line graph G2 has the largest overlap size S. Therefore, the CPU 11 determines the display colors of the first line graph G1 and the second line graph G2 to be two colors that are opposite each other on the color wheel. For group 2, the only two line graphs G that belong to group 2 are the third line graph G3 and the fifth line graph G5. Therefore, the CPU 11 determines the display colors of the third line graph G3 and the fifth line graph G5 to be two colors that are opposite each other on the color wheel. Here, a color wheel refers to a circular arrangement of multiple hues that are perceived as continuously changing. Examples of color wheels include the Munsell color system, the Ostwald color system, and the PCCS (Japan Color Research Color System) color wheel, and any of these color wheels may be used. Two colors positioned opposite each other on the color wheel refer to two colors positioned on opposite sides of the center point of the color wheel. In the example shown in Figure 14, blue and yellow are used as the two colors positioned opposite each other on the color wheel.

[0032] After step S403 is completed, the CPU 11 determines the display colors of the other line graphs G so that the display colors of the line graphs G within the same group are different from each other (step S404). In the example of FIG. 14, the CPU 11 determines the display color of the fourth line graph G4 of group 1 to be red. Then, the CPU 11 draws each line graph G in the determined display color (step S405). The processing content of step S405 is the same as step S207 of FIG. 9. FIG. 12 shows the line graph G displayed when the grouping and color coding shown in FIG. 14 are performed. In FIG. 12, the line graphs G1, G2, and G4 with long intersection sections C are displayed in different colors, and the line graphs G3 and G5 with short intersection sections C with these line graphs G1, G2, and G4 are displayed in the same color as the line graphs G1 and G2, respectively. After step S405 is completed, the CPU 11 ends the color coding processing. According to the third color-coding method, line graphs G having long crossing sections C can be easily distinguished from each other using a small number of colors.

[0033] As described above, the scientific calculator 1 according to this embodiment includes a CPU 11. When the CPU 11 causes the display unit 15 to display a graph image 20 including a first line graph G1 and second and third line graphs G2 and G3 that intersect with the first line graph G1, and when the display color of the first line graph G1 is set to a different color from the display color of at least one of the second and third line graphs G2 and G3, the CPU 11 determines the display colors of the first, second, and third line graphs G1, G2, and G3 based on a comparison between an overlap size S1, which is the size of the intersection section C1 where the second line graph G2 intersects with the first line graph G1, and an overlap size S2, which is the size of the intersection section C2 where the third line graph G3 intersects with the first line graph G1. This determines the display color of each line graph G according to the size of the intersection section C of the line graph G, allowing each line graph G to be displayed in an appropriate color according to the manner in which the line graphs G intersect. This allows multiple line graphs G to be displayed in an easy-to-read manner.

[0034] Furthermore, in the first color-coding method, when the difference between the overlap size S1 and the overlap size S2 is equal to or greater than a first threshold and the overlap size S2 is greater than the overlap size S1, the CPU 11 determines the display color of the first line graph G1 and the second line graph G2 to be a first color, and determines the display color of the third line graph G3 to be a second color different from the first color. As a result, line graphs G that have large intersection sections C and are close to each other are displayed in different colors. Therefore, even with a small number of colors (even when the number of colors that can be used is limited), the line graphs G can be displayed in a manner that makes it easy to distinguish between adjacent line graphs G.

[0035] Furthermore, in the second color-coding method, when the difference between the overlap size S1 and the overlap size S2 is equal to or greater than a first threshold and the overlap size S2 is smaller than the overlap size S1, the CPU 11 determines the display color of the first line graph G1 and the second line graph G2 to be a first color, and determines the display color of the third line graph G3 to be a second color different from the first color. As a result, line graphs G having large intersection sections C and strong correlations with each other are displayed in the same color. Therefore, even with a small number of colors (even when the number of colors that can be used is limited), it is possible to display line graphs G in a manner that makes it easy to recognize line graphs G that are strongly correlated together. Furthermore, it is possible to display line graphs G in a manner that allows visual differentiation between multiple line graphs G that are strongly correlated and line graphs G that are weakly correlated with each other.

[0036] Furthermore, in the second color-coding method, when the difference between the overlap size S1 and the overlap size S2 is less than a first threshold, the CPU 11 determines the display color of the first line graph G1 to be a first color and determines the display colors of the second line graph G2 and the third line graph G3 to be a second color different from the first color. This also makes it possible to display the line graphs G in a manner that makes it easy to recognize line graphs G that are highly correlated together. Furthermore, it is possible to display the line graphs G in a manner that makes it possible to visually differentiate multiple line graphs G that are highly correlated from line graphs G that are weakly correlated with them.

[0037] Furthermore, in the third color-coding method, the CPU 11 identifies two line graphs G that correspond to the largest mutual overlap size S of the three line graphs G, and determines the display colors of the two line graphs G to be two colors that are located opposite each other on the color wheel. This allows line graphs G that have large crossing sections C and are close to each other to be displayed in colors that make them easy to distinguish from each other. This makes it easier to distinguish between adjacent line graphs G.

[0038] The CPU 11 also displays the first line graph G1, the second line graph G2, and the third line graph G3 in a display area 151 that displays a predetermined range on a coordinate plane. The CPU 11 then sets a graph area RG within a predetermined distance from the plot position of each of the first line graph G1, the second line graph G2, and the third line graph G3 in the display area 151. The CPU 11 then derives an overlap size S1 based on the distribution of intersection sections C1 where the graph area RG1 of the first line graph G1 overlaps with the graph area RG2 of the second line graph G2. The CPU 11 then derives an overlap size S2 based on the distribution of intersection sections C2 where the graph area RG1 overlaps with the graph area RG3 of the third line graph G3. By using a graph area RG with a constant width in this manner, an appropriate intersection section C can be set according to the intersection pattern of the line graph G. Furthermore, the CPU 11 can derive an appropriate overlap size S for the line graph G based on the distribution of the intersection sections C.

[0039] Furthermore, the CPU 11 sets weight values ​​Vw1, Vw2, and Vw3 for pixels P within a predetermined distance range from the plot positions of the first line graph G1, the second line graph G2, and the third line graph G3 so that the weight values ​​Vw1, Vw2, and Vw3 have smaller values ​​for pixels P that are farther away from the plot positions. The CPU 11 derives a sum Va1 of the weight values ​​Vw1 and Vw2 for each pixel P in the display area 151 to which both the weight values ​​Vw1 and Vw2 have been set, and derives an overlap size S1 based on the distribution of the sum Va1 in the display area 151. The CPU 11 also derives a sum Va2 of the weight values ​​Vw1 and Vw3 for each pixel P in the display area 151 to which both the weight values ​​Vw1 and Vw3 have been set, and derives an overlap size S2 based on the distribution of the sum Va2 in the display area 151. Using such weight values ​​Vw can increase the size of the intersection section C where the line graphs G are closer to each other. This allows a more appropriate intersection section C to be set in accordance with the manner in which the line graphs G intersect. Furthermore, based on the distribution of the intersection sections C, a more appropriate overlap size S of the line graph G can be derived.

[0040] The CPU 11 also derives the overlap size S1 as the sum of the sum Va1 in a section where first pixels P1, each having an additional value Va1 equal to or greater than the second threshold, are continuously distributed in the X-axis direction of the coordinate plane for a period equal to or greater than the third threshold, and in a section where first pixels P1 are continuously distributed in the Y-axis direction for a period equal to or greater than the third threshold. The CPU 11 also derives the overlap size S2 as the sum of the sum Va2 in a section where second pixels P2, each having an additional value Va2 equal to or greater than the second threshold, are continuously distributed in the X-axis direction for a period equal to or greater than the third threshold, and in a section where second pixels P2 are continuously distributed in the Y-axis direction for a period equal to or greater than the third threshold. This allows for excluding, from the derivation of the overlap size S, intersection sections C where the line graphs G are easily distinguishable from each other, such as when the line graphs G intersect at an angle closer to a right angle than 45 degrees. Furthermore, it allows for deriving the overlap size S to include, as targets for deriving the overlap size S, intersection sections C where the line graphs G are close to each other over a certain length or greater, making them difficult to distinguish, such as when the line graphs G intersect at an angle closer to parallel than 45 degrees.

[0041] In the graph display method according to this embodiment, the CPU 11 determines the display colors of the first line graph G1, the second line graph G2, and the third line graph G3 using the above-described method. The program 131 according to this embodiment causes the CPU 11 to function as a control unit that determines the display colors of the first line graph G1, the second line graph G2, and the third line graph G3 using the above-described method. This allows the multiple line graphs G to be displayed in an easy-to-read manner.

[0042] The present invention is not limited to the above-described embodiment and may be modified in various ways. For example, in the above-described embodiment, the sum of the added values ​​Va (i.e., the sum of the integrated values ​​Vi obtained by integrating the added values ​​Va) is used as the overlap sizes S1 to S3 (first to third sizes). However, the overlap size S is not limited to this. Any value may be used as long as it represents the size of the intersection section C where the line graphs G intersect. For example, the overlap size S may be the larger of the length of the intersection section C in the X-axis direction and the length of the intersection section C in the Y-axis direction. The overlap size S may also be the area (number of pixels) of the intersection section C. Furthermore, the overlap size S is derived using the added values ​​Va equal to or greater than the second threshold. However, the overlap size S is not limited to this. The overlap size S may also be the sum of the integrated values ​​Vi obtained by integrating all the added values ​​Va. Furthermore, the overlap size S is determined as the sum of the added values ​​Va in the intersection sections C that are continuously distributed over a length equal to or greater than the third threshold. However, the overlap size S is not limited to this. The overlap size S may simply be the sum of the added values ​​Va.

[0043] Furthermore, the method for determining the display colors of the line graphs G1 to G3 is not limited to the one exemplified in the above embodiment, and any method based on the comparison results between the overlap size S1 (first size) and the overlap size S2 (second size) can be used.

[0044] In the above embodiment, the size of the section where the second line graph G2 intersects with the first line graph G1 has been described as the overlap size S1, but the size of the section where the second line graph G2 does not intersect with the first line graph G1 may be replaced with the above-mentioned overlap size S1. Similarly, the overlap size S2 and the overlap size S3 may also be replaced with the size of the section where the graphs do not intersect.

[0045] In the above embodiment, the CPU 11 is described as determining the display colors of the first line graph G1, the second line graph G2, and the third line graph G3. However, the CPU 11 may determine the display colors of figures other than line graphs. For example, the first line graph G1 in the above embodiment may be replaced with a first figure, the second line graph G2 with a second figure, and the third line graph with a third figure.

[0046] Furthermore, in the above embodiment, the graph display device has been described using the scientific calculator 1 as an example, but is not limited thereto. The graph display device may be any device capable of displaying multiple graphs on a display unit, such as a smartphone, tablet device, PC, or learning device, or may be a server that provides a program for displaying multiple graphs on the above-mentioned device. Here, the device to which the server provides the program may have a browser function, and the results of executing the program on the server may be displayed via the browser function. The program for drawing the line graph G may be a dedicated graph application, or may be a program that includes a line graph G drawing function as one of its various functions, such as spreadsheet software or a mathematical tool.

[0047] In the above description, an example has been disclosed in which a flash memory in the storage unit 13 is used as a computer-readable medium for the program according to the present invention, but this is not limiting. Other computer-readable media may include information recording media such as a hard disk drive (HDD), a solid state drive (SSD), and a CD-ROM. Furthermore, a carrier wave may also be used as a medium for providing data for the program according to the present invention via a communication line.

[0048] Furthermore, it goes without saying that the detailed configuration and detailed operation of each component of the scientific calculator 1 in the above embodiment can be modified as appropriate without departing from the spirit of the present invention.

[0049] Although the embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, but includes the scope of the invention described in the claims and its equivalents. [Explanation of symbols]

[0050] 1... Scientific calculator (graph display device), 11... CPU (control unit, control means), 15... Display unit, 20... Graph image, G1... First line graph, G2... Second line graph, G3... Third line graph, S1... Overlap size (first size), S2... Overlap size (second size)

Claims

1. A graph display device comprising: a control unit that determines the display colors of the first line graph, the second line graph, and the third line graph based on a comparison result between a first size, which is the size of the section where the second line graph intersects with the first line graph, and a second size, which is the size of the section where the third line graph intersects with the first line graph, when a graph image including a first line graph and a second line graph and a third line graph that intersect with the first line graph is displayed on a display unit, and when the display color of the first line graph is made different from the display color of at least one of the second line graph and the third line graph,

2. When the difference between the first size and the second size is equal to or greater than a first threshold value and the second size is greater than the first size, the control unit determines the display colors of the first line graph and the second line graph to be a first color and determines the display color of the third line graph to be a second color different from the first color. The graph display device according to claim 1 .

3. When the difference between the first size and the second size is equal to or greater than a first threshold value and the second size is smaller than the first size, the control unit determines the display colors of the first line graph and the second line graph to be a first color and determines the display color of the third line graph to be a second color different from the first color. The graph display device according to claim 1 .

4. When the difference between the first size and the second size is less than a first threshold value in the comparison result, the control unit determines a display color of the first line graph to be a first color and determines display colors of the second line graph and the third line graph to be a second color different from the first color. The graph display device according to claim 1 .

5. When the second line graph and the third line graph further intersect in the graph image, the control unit identifies two line graphs corresponding to the largest size among the first size, the second size, and a third size, which is the size of a section where the third line graph intersects with the second line graph, and determines the display colors of the two line graphs to be two colors located at opposite positions on a color wheel. The graph display device according to claim 1 .

6. The control unit displaying the first line graph, the second line graph, and the third line graph within a display area in which a predetermined range on a coordinate plane is displayed; In the display area, a graph area is set within a predetermined distance range from a plot position of each of the first line graph, the second line graph, and the third line graph; deriving the first size based on a distribution of first intersection sections where a first graph region of the first line graph and a second graph region of the second line graph overlap; deriving the second size based on a distribution of second intersection sections where the first graph region and a third graph region of the third line graph overlap; The graph display device according to claim 1 .

7. The control unit displaying the first line graph, the second line graph, and the third line graph within a display area in which a predetermined range on a coordinate plane is displayed; a first weight value is set so that, among pixels within a predetermined distance range from the plot position of the first line graph, the value of a pixel increases as the pixel distance from the plot position increases; a second weight value is set so that, among pixels within a predetermined distance range from the plot position of the second line graph, the value of a pixel increases as the pixel distance from the plot position increases; a third weight value is set so that, among pixels within a predetermined distance range from the plot position of the third line graph, the value of a pixel increases as the distance from the plot position increases; deriving a first sum of the first weight value and the second weight value for each pixel in the display area to which both the first weight value and the second weight value are set, and deriving the first size based on a distribution of the first sum in the display area; deriving a second sum of the first weight value and the third weight value for each pixel in the display area to which both the first weight value and the third weight value are set, and deriving the second size based on a distribution of the second sum in the display area; The graph display device according to claim 1 .

8. The control unit deriving, as the first size, a sum of the first added values ​​in a section where first pixels having the first added value equal to or greater than the second threshold are distributed consecutively for a third threshold or more in a first coordinate axis direction of the coordinate plane, and in a section where the first pixels are distributed consecutively for a third threshold or more in a second coordinate axis direction orthogonal to the first coordinate axis; deriving, as the second size, a sum of the second added values ​​in a section where second pixels having the second added value equal to or greater than the second threshold are distributed consecutively in the first coordinate axis direction for a number equal to or greater than a third threshold, and in a section where second pixels are distributed consecutively in the second coordinate axis direction for a number equal to or greater than the third threshold; The graph display device according to claim 7 .

9. 1. A computer-implemented method for displaying graphs, comprising: When a graph image including a first line graph and a second line graph and a third line graph intersecting the first line graph is displayed on a display unit, and when the display color of the first line graph is made different from the display color of at least one of the second line graph and the third line graph, the display colors of the first line graph, the second line graph, and the third line graph are determined based on a result of comparison between a first size, which is the size of a section where the second line graph intersects with the first line graph, and a second size, which is the size of a section where the third line graph intersects with the first line graph. Graph display method.

10. A program that causes a computer to operate as a control means, When the control means causes a display unit to display a graph image including a first line graph and a second line graph and a third line graph intersecting the first line graph, and when the display color of the first line graph is made different from the display color of at least one of the second line graph and the third line graph, the control means determines the display colors of the first line graph, the second line graph, and the third line graph based on a comparison result between a first size, which is the size of a section where the second line graph intersects with the first line graph, and a second size, which is the size of a section where the third line graph intersects with the first line graph. program.

Images