Electronic device, display control method, and program

Abstract

To allow a user to easily know how to respond in a case where a graph of an input function formula is not displayed.SOLUTION: An electronic device (10, 20) includes a control unit (13, 22) configured to, when a graph of a function formula including at least one variable is drawn and displayed on a display unit (12, 21) in response to an input of a numerical value corresponding to a drawing range of the graph to a variable of the function formula, display, on the display unit, a guide screen (P141) including a plurality of options for displaying the drawn graph within the display unit, in response to determining that the whole graph in the drawing range passes outside a display range designated in advance on the display unit.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] Some calculation devices called scientific calculators are capable of displaying a graph of a function formula (a calculation formula including variables). Some calculation devices of this type are capable of easily displaying a graph of any function formula at an appropriate size without considering the setting of the coordinate range of the coordinate system in which the graph is drawn (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-185723 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional graph display methods for computing devices, including the display method described in Patent Document 1, when a graph is displayed with both the vertical and horizontal axis ranges set, the graph may not be displayed on the display screen. In this case, it is difficult for a user of the computing device to know the reason (cause) why the graph is not displayed and how to deal with it.

[0005] An object of the present invention is to make it possible to easily know what to do when a graph of an inputted functional formula is not displayed. [Means for solving the problem]

[0006] In one embodiment, an electronic device includes a control unit that, when a numerical value corresponding to a drawing range of a graph is input into a variable of a function formula including at least one variable, thereby drawing a graph of the function formula and displaying it on a display unit, and when it determines that the entire drawing range graph passes outside a display range previously specified on the display unit, displays on the display unit a guide screen including a plurality of options for displaying the drawn graph within the display unit. Effect of the Invention

[0007] According to the above-described aspect, it is possible to easily know what to do when a graph of an inputted function formula is not displayed. [Brief description of the drawings]

[0008] [Figure 1] 1 is a front view showing an example of the external configuration of a scientific calculator according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram showing an example of the configuration of an electronic circuit of a scientific calculator. [Diagram 3] 1 is a flowchart (part 1) illustrating an example of a graph display process performed by the scientific calculator according to the first embodiment. [Figure 4] 13 is a flowchart (part 2) illustrating an example of a graph display process performed by the scientific calculator according to the first embodiment. [Diagram 5] 5A and 5B are diagrams for explaining an example of the relationship between the graph of an inputted function formula and the graph display area. [Figure 6] 6A to 6D are diagrams illustrating an example of screen transition in a case where a guide screen is displayed. [Figure 7] FIG. 11 is a front view showing an example of an external configuration of an electronic device according to a second embodiment. [Figure 8] FIG. 2 is a block diagram illustrating an example of a hardware configuration of a computer. [Figure 9] FIG. 1 is a block diagram showing an example of the configuration of a learning system using a communication network. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In this specification, drawing a graph is intended to represent the relationship between variables (e.g., x value) and solutions (e.g., y value) in a functional formula on a predetermined plane or space, and drawing and displaying a graph is intended to visualize and display only a specified range of the predetermined plane or space in which the relationship between variables and solutions in the functional formula is represented on the display unit 12. Therefore, in the following description, "drawing and displaying a graph" and similar expressions also include cases in which a part or all of the drawn graph is not displayed on the display unit. Note that the functional formula in this specification includes a functional formula of a constant function (zeroth order function) such as y=1 (y=0·x+1).

[0010] [First embodiment] 1 has a key input unit 11, a display unit 12, and a battery power source (not shown) provided on one main surface of the device housing. The device housing has a distance (dimension in the thickness direction) between the main surface and its back surface that is sufficiently small compared to the vertical and horizontal dimensions of the main surface on which the key input unit 11, the display unit 12, etc. are provided, and can be small enough to be held and operated by a user with one hand. The scientific calculator 10 can be an example of an electronic device (graph display device) that can draw and display a graph of an inputted functional formula.

[0011] The key input section 11 is provided with a group of numeric value / operation symbol keys 111 for inputting numeric values ​​and mathematical expressions and for instructing the execution of calculations, a group of function keys 112 for inputting various functions, and cursor keys 113 for moving a cursor displayed on the display section 12 and selecting data items.

[0012] The numeric / arithmetic symbol key group 111 includes [0] to [9] (numeric) keys, [+], [-], [×], [÷] (arithmetic operator) keys, an [EXE] (execute) key 111E, an [AC] (clear) key, etc. The function function key group 112 includes an [x] (variable) key, a [□ / □] (fraction) key, a [√□] (root) key, a [sin] (sine) key, a [cos] (cosine) key, a [tan] (tangent) key, etc.

[0013] The cursor keys 113 include an [↑] (up) key 113U (first key), a [↓] (down) key 113D (second key), a [←] (left) key 113L (third key), a [→] (right) key 113R (fourth key), a [↑↓] (scroll) key 113S, and a [◯] (confirmation key) 113C. The cursor keys 113 are provided on the right side of the front of the main body of the scientific calculator 10 where the key input unit 11 is provided, thereby improving operability for users who are mainly right-handed.

[0014] Further, to the left of the cursor keys 113 in the key input unit 11, there are arranged a key for turning the power on and off, a setting screen start key 114 for displaying a setting screen related to the operation and manipulation of the scientific calculator 10, etc. The display unit 12 may be a dot-matrix type liquid crystal display unit or the like. Note that the external configuration of the scientific calculator 10, for example, the number and arrangement of keys of the key input unit 11, is not limited to the configuration exemplified in FIG.

[0015] 2, the electronic circuit in the scientific calculator 10 of this embodiment includes a key input unit 11, a display unit 12, a battery power source BT, a control unit 13, a storage unit 14, a medium reading unit 15, and a communication unit 16. The key input unit 11, the display unit 12, the control unit 13, the storage unit 14, the medium reading unit 15, and the communication unit 16 are connected to each other via a bus 17. The key input unit 11, the display unit 12, the control unit 13, the storage unit 14, the medium reading unit 15, and the communication unit 16 are connected to the battery power source BT by power supply wiring (not shown), and operate with power supplied from the battery power source BT. The battery power source BT may be a combination of multiple types of batteries (for example, a combination of a solar cell and a button battery, a coin battery, or a cylindrical battery).

[0016] The control unit 13 controls the operation of each circuit unit in accordance with a calculator control program stored in the storage unit 14, and executes various arithmetic processing in response to key input signals from the key input unit 11 and signals received from the outside via the communication unit 16. The control unit 13 has at least one processor such as a CPU (Central Processing Unit). The communication unit 16 has a wireless communication device that performs wireless communication with an external device in accordance with, for example, Bluetooth (registered trademark), Bluetooth Low Energy (registered trademark), or other short-range wireless communication standards. The communication unit 16 may have a terminal for connecting a dedicated or general-purpose transmission cable that can be used for communication with an external device.

[0017] The calculator control program may be pre-stored in memory unit 14, or may be read and stored in memory unit 14 from a portable recording medium M such as a memory card via medium reading unit 15. The calculator control program may be downloaded and stored in memory unit 14 via communication unit 16 from a Web server on a communications network. Memory unit 14 has a ROM (Read Only Memory) and a RAM (Random Access Memory) and can store not only the calculator control program but also function formulas and the like input by the user.

[0018] In the scientific calculator 10 thus configured as an electronic device, the control unit 13 controls the operation of each circuit unit in accordance with instructions written in a calculator control program, and the software and hardware operate in cooperation to realize various functions. The scientific calculator 10 can, for example, draw a graph of a functional formula input using the key input unit 11 or the like and display it on the display unit 12. When drawing a graph of a functional formula and displaying it on the display unit 12, the scientific calculator 10 of this embodiment performs a graph display process in accordance with the flowcharts exemplified in Figures 3 and 4. The instructions executed by the control unit 13 in the graph display process, which will be described later with reference to Figures 3 and 4, are included in the calculator control program.

[0019] In the scientific calculator 10, the components shown as multiple blocks in Fig. 2 may be included in a single piece of hardware, or the components shown as a single block in Fig. 2 may be a combination of multiple pieces of hardware. For example, the scientific calculator 10 may include an FPGA (Field Programmable Gate Array) including part or all of the control unit 13 and the memory unit 14, or an ASIC (Application Specific Integrated Circuit), etc.

[0020] Next, an example of the graph display process performed by the scientific calculator 10 of this embodiment will be described with reference to Figures 3 and 4. When the user, for example, selects graph drawing from the menu screen and inputs a function formula, and then subsequently performs an operation to instruct execution of graph drawing, the scientific calculator 10 starts the graph display process illustrated in Figures 3 and 4. The graph display process starts from step S100 illustrated in Figure 3. The process of each step included in the graph display process is performed by the control unit 13 alone or in cooperation with the key input unit 11, the display unit 12, the storage unit 14, etc.

[0021] In step S100, the control unit 13 determines whether the display setting of the range specification screen is on. The range specification screen is a screen for specifying the range of the graph of the functional formula to be displayed on the display unit 12. The range specification screen can be, for example, a screen on which the display range and scale (memory interval) of the x-axis (horizontal axis) and the display range and scale (memory interval) of the y-axis (vertical axis) can be specified. The determination in step S100 is made based on the setting information stored by the control unit 13 in a predetermined memory area of ​​the storage unit 14. The control unit 13 determines that the display setting is on when the setting is set to display the range specification screen before drawing the graph (displaying it on the display unit 12).

[0022] When it is determined that the display setting of the range specification screen is ON (step S100; YES), the control unit 13 holds graph drawing data for the already inputted function formula in the buffer memory of the storage unit 14, and determines whether or not the function formula has been changed since then (step S101). The determination in step S101 is made based on history information stored by the control unit 13 in a predetermined memory area of ​​the storage unit 14. The graph drawing data held in the buffer memory is, for example, image data displayed on the display unit 12 in the previous graph display process, and may include at least a part of the graph.

[0023] When it is determined that the graph drawing data is held and the function formula has not been changed (step S101; YES), the control unit 13 reads out the held graph drawing data from the storage unit 14 and displays it on the display unit 12 (step S102), and ends the graph display process. In this way, even if the display setting of the range specification screen is on (step S100; YES), when it is determined that the drawing data of the function formula for drawing a graph is held (step S101; YES), the held graph drawing data is displayed on the display unit 12 without displaying the range specification screen. The graph drawing data displayed on the display unit 12 may include a part of the graph within at least a part of the display range of the x value, for example. Therefore, when the drawing data of the function formula for drawing a graph is held, it is possible to omit the display of the range specification screen, the process of changing the display range of the x value and the y value, and the like, and to save the trouble of the user operation.

[0024] When it is determined that the graph drawing data is not held or that the function formula has been changed (step S101; NO), the control unit 13 causes the range specification screen to be superimposed on the display unit 12 (step S103). Thereafter, the control unit 13 accepts a user operation on the range specification operation screen using the key input unit 11 (step S104) and waits for the range specification operation to end (step S105). In step S104, if the accepted operation is an operation to change any of the display range and scale of the x value and the display range and scale of the y value, the control unit 13 changes the corresponding value. In this case, the control unit 13 determines that the range specification operation has not ended (step S105; NO) and waits for the next user operation. When it is determined that the range specification operation has ended (step S105; YES), the control unit 13 draws a graph based on the display range of the x value and the y value at the time of the end of the range specification operation and causes the display unit 12 to display it (step S106), and ends the graph display process. In step S106, the control unit 13 derives the x value of each dot in the x-axis direction based on, for example, the display range of the x value at the end of the range designation operation (i.e., the current time) and the number of dots in the x-axis direction of the graph display area on the display unit 12. The control unit 13 also derives the range of the y value of each dot in the y-axis direction based on the display range of the y value at the end of the range designation operation and the number of dots in the y-axis direction of the graph display area on the display unit 12. Thereafter, the control unit 13 inputs the derived x value of each dot into a function formula to sequentially calculate the y value, and draws a graph on the xy plane that expresses the relationship between the x value input into the function formula and the y value that is the solution. At this time, the control unit 13 causes the display unit 12 to display only the area within the xy plane on which the graph is drawn that is specified by the display range of the x value and the y value at the end of the range designation operation.

[0025] In this way, when the display setting of the range specification screen is on (step S100; YES) and it is determined that the drawing data of the functional formula to be graphed is not held (step S101; NO), the user can specify the display range of the x and y values ​​on the range specification screen before the graph of the input functional formula is displayed on the display unit 12. That is, before the graph is displayed, the user can check whether the graph will be displayed on the display unit 12 based on the currently specified display range of the x and y values, and can change the display range of the x and y values ​​so that the graph will be displayed.

[0026] On the other hand, when it is determined that the display setting of the range specification screen is off (step S100; NO), the control unit 13 then sequentially calculates y values ​​corresponding to the x values ​​of each dot in the x-axis direction derived based on the currently specified display range of x values ​​(step S107). In step S107, the control unit 13 calculates x values ​​corresponding to each dot in the x-axis direction in the graph display range based on the number of dots in the x-axis direction in the graph display range of the display unit 12 and the minimum and maximum x values ​​specified on the range specification screen. Also, in step S107, the control unit 13 sequentially calculates a solution obtained by substituting the calculated x values ​​corresponding to each dot into a function formula as a y value. The calculation method of the x values ​​and y values ​​in step S107 can be, for example, a calculation method in a graph drawing function of a well-known scientific calculator, and is not limited to a specific method.

[0027] Next, the control unit 13 compares the y values ​​calculated in step S107 with the minimum and maximum values ​​in the currently specified display range of y values ​​(step S108). Specifically, for each y value calculated in step S107, it is determined whether it is equal to or greater than the minimum value and equal to or less than the maximum value in the currently specified display range of y values, and counts and holds the number of y values ​​that are equal to or greater than the minimum value and equal to or less than the maximum value in the currently specified display range of y values ​​among the sequentially calculated y values.

[0028] After step S108, the control unit 13 judges whether or not one or more of the y values ​​calculated in step S107 are within the currently specified display range of the y values ​​(step S109). If it is judged that one or more of the calculated y values ​​are within the display range of the y values ​​(step S109; YES), the control unit 13 draws a graph based on the currently specified display range of the x values ​​and y values, displays it on the display unit 12 (step S110), and ends the graph drawing process.

[0029] On the other hand, when it is determined that all the calculated y values ​​are outside the display range of the y values ​​(step S109; NO), the control unit 13 performs the process of step S111 and subsequent steps illustrated in FIG. 4. In step S111, the control unit 13 causes the display unit 12 to superimpose and display a guide screen (sub-window) including information indicating that the graph is drawn outside the display range and display control options. In the control unit 13 performing the process illustrated in FIG. 4, the display control options include a first display control content for accepting a change in the display range by a user operation and controlling the display range, a second display control content for automatically adjusting the display range so that the graph drawn based on the y value calculated in step S107 is displayed, and a third display control content for displaying the display range without changing it. After displaying the guide screen in step S111, the control unit 13 waits for any one of the first display control content (change in the display range by the user), the second display control content (automatic adjustment of the display range), and the third display control content (cancellation) of the guide screen to be selected. For example, as shown in FIG. 4, the control unit 13 repeats the following in this order until any one of the first display control content, the second display control content, and the third display control content of the guidance screen is selected: determining whether or not the first display control content has been selected (step S112), determining whether or not the second display control content has been selected (step S113), and determining whether or not the third display control content has been selected (step S114) (a loop of step S112; NO, step S113; NO, step S114; NO is repeated).

[0030] When it is determined that the first display control content is selected (step S112; YES), the control unit 13 causes the range specification screen to be superimposed on the display unit 12 (step S115). Thereafter, the control unit 13 accepts a user operation on the range specification screen using the key input unit 11 (step S116) and waits for the range specification operation to end (step S117). In step S116, when the control unit 13 determines that the accepted operation is an operation to change any of the display range and scale of the x value and the display range and scale of the y value, it changes the corresponding value. Thereafter, the control unit 13 judges whether the range specification operation has ended (step S117), and when it is determined that the range specification operation has not ended (step S117; NO), it waits for the next user operation. On the other hand, when it is determined that the range specification operation has ended (step S117; YES), the control unit 13 draws a graph based on the display range of the x value and the y value at the time of the end of the range specification operation and causes the display unit 12 to display it (step S118), and ends the graph display process. The processing of steps S115 to S118 may be, for example, the same as or similar to steps S103 to S106 described above with reference to Fig. 3. When the first display control content is selected, the user can consider how to specify (change) the display range of the x and y values ​​in order to display the graph drawn outside the display range on the display unit 12.

[0031] When it is determined that the second display control content is selected (step S113; YES), the control unit 13 changes the display range according to the range of the numerical values ​​corresponding to the calculated variables. Specifically, the display range of the y values ​​is changed to the minimum value to the maximum value of the y values ​​calculated for each x value within the display range of the currently specified x values ​​(step S119). In step S119, the control unit 13 extracts, for example, the minimum value and the maximum value of the y values ​​calculated in step S107, and changes the minimum value and the maximum value of the y values ​​that specify the display range of the y values ​​to the extracted minimum value and maximum value. Thereafter, the control unit 13 draws a graph based on the x values ​​and the display range of the changed y values, displays it on the display unit 12 (step S120), and ends the graph display process. When the second display control content is selected, the user can save the trouble of performing an operation to display a graph drawn outside the display range on the display unit 12.

[0032] When it is determined that the third display control content has been selected (step S114; YES), the control unit 13 redraws the graph based on the currently specified display range of x and y values, displays it on the display unit 12 (step S121), and ends the graph display process. In other words, when it is determined that the third display control content has been selected, the graph is not displayed on the screen (within the graph display area) of the display unit 12. Note that even when it is determined that the third display control content has been selected, the control unit 13 can cause the display unit 12 to display the graph by detecting a user operation, for example, an operation of the cursor key 113, an operation to change the display range using a range specification screen, etc.

[0033] Fig. 5A shows an example of a screen P130 for inputting a functional formula with an x ​​value as a variable and a y value as a solution. Fig. 5B shows an example of the relationship between graphs drawn on the xy plane for several functional formulas and the graph display area P121. The graph display area P121 is an area displayed on the display unit 12 within the xy plane on which the graph is drawn, and is specified by the display range of the x and y values ​​on the range specification screen.

[0034] The screen P130 shown in FIG. 5A shows examples of function equations with y values ​​as solutions, such as y1=x and y2=x.2 Two function formulas, y1=x and +3, are input. The method of inputting the function formula is not limited to a specific method. The user of the scientific calculator 10 can select one of the five function formula input sections "y1" to "y5" displayed on the screen P130 by, for example, operating the cursor key 113. The selected function formula input section is displayed differently (inverted display) from the other function formula input sections. On the screen P130 of FIG. 7A, the function formula input section P131 in which the function formula y1=x is input is selected. When the function formula input section is selected and, for example, a "SELECT" button P132 displayed at the bottom left of the screen P130 is pressed, the function formula can be input to the selected function formula input section. Also, when the function formula input section is selected and, for example, a "DRAW" button P133 displayed at the bottom right of the screen P130 is pressed, the graph of the function formula input to the selected function formula input section can be drawn and displayed on the display unit 12. The display unit 12 may display not only a graph of one function formula, but also graphs of two or more function formulas superimposed on each other.

[0035] For example, when drawing and displaying a graph of the function formula "y1=x" on screen P130 shown in Fig. 5A, scientific calculator 10 draws a graph of "y=x" within the section in the x-axis direction corresponding to the display range of x values ​​in the xy plane, as shown in Fig. 5B. In Fig. 5B, graph display area P121 is shown superimposed on a rectangular partial plane of the xy plane, -8≦x≦9, -6≦y≦17. Graph display area P121 is a rectangular area of ​​-5≦x≦5, -2≦y≦4.

[0036] At this time, the graph of the function formula y=x that the scientific calculator 10 draws on the xy plane is, for example, only the section shown by the solid line in FIG. 5B. Also, the scientific calculator 10 displays only the graph display area P121 of the xy plane on the display unit 12. Therefore, in the example shown in FIG. 5B, only the portion of the graph of the function formula y=x drawn on the xy plane that is -2≦x≦4 is displayed on the display unit 12. Also, when drawing and displaying the graph of the function formula y=x+8, if the graph display area P121 is a rectangular area of ​​-5≦x≦5, -2≦y≦4, only the portion of the graph of the function formula y=x+8 that is -5≦x≦4 is displayed on the display unit 12, and a part of the graph of the function formula y=x+8 is displayed at the upper left corner of the graph display area P121 of the display unit 12.

[0037] Furthermore, when drawing and displaying a graph of the functional formula y=x+11, if the graph display area P121 is a rectangular area with -5≦x≦5, -2≦y≦4, the solution y within the range of -5≦x≦5 will be 6≦y≦16, and the entire graph of the functional formula y=x+11 will not be displayed in the graph display area P121 of the display unit 12. In this way, when drawing and displaying a graph of an input functional formula, if all of the y values ​​(solutions to the functional formula) corresponding to each x value within the display range of the x value (variable) are outside the display range of the y value, the entire graph of the functional formula may not be displayed on the display unit 12 (within the graph display area P121).

[0038] In this way, when the graph of the above-mentioned function formula y=x+8 is drawn and displayed, the user knows how to change the graph display area P121 (i.e., how to specify the display range of the x and y values) based on the position of the displayed portion in the graph display area P121. On the other hand, when the graph of the above-mentioned function formula y=x+11 is drawn and displayed, the entire graph is not displayed in the graph display area P121. For this reason, the user must check whether the graph is not displayed because there is an error in the input function formula, or whether the entire graph drawn on the xy plane passes outside the graph display area P121. In addition, if the entire graph drawn on the xy plane passes outside the graph display area P121, the user must consider how to change the graph display area P121 (i.e., how to specify the display range of the x and y values) so that the graph can be displayed. In addition, the user must assume that the graph may not be displayed in the graph display area P121 because the load of the process of calculating the y value becomes high and it takes a long time to display the drawn graph on the display unit 12.

[0039] 3 and 4, in the scientific calculator 10 of this embodiment, when the control unit 13 determines that all of the calculated y values ​​are outside the display range of the y values ​​(step S109; NO), a guide screen including information indicating that the entire graph will be drawn outside the display range is displayed on the display unit 12 (step S111). By displaying this guide screen, the user of the scientific calculator 10 of this embodiment can easily know that if the display ranges of the x and y values ​​currently specified are left unchanged, the entire graph drawn on the xy plane will pass outside the graph display area P121, in other words, that in order to display the graph, it is necessary to change the display range of at least one of the x and y values.

[0040] Next, a specific example will be described with reference to Fig. 6A to Fig. 6D. In the following description, it is assumed that the display setting of the range specification screen is in an OFF state, and the display ranges of the x and y values ​​specified by the range specification screen at the start of the graph display process are -5≦x≦5 and -2≦y≦4. In the screen P130 illustrated in Fig. 6A, the function formula "y1=x+11" is input in the function formula input section. When the user of the scientific calculator 10 performs an operation of pressing the "DRAW" button P113, the control section 13 performs the graph display process described above with reference to Figs. 3 and 4 in order to draw a graph of the function formula "y=x+11" and display it on the display section 12. At this time, if the graph display area P121 is -5≦x≦5, -2≦y≦4, the control unit 13 displays, for example, the screen P120 of Fig. 6B on the display unit 12, and substitutes the x value corresponding to each dot in the x-axis direction in the graph display area P121 into the function formula "y=x+11" to sequentially calculate the y value (solution) (step S107). After that, the control unit 13 compares the calculated y value with the currently specified display range of the y value (minimum and maximum values) (step S108).

[0041] In the illustrated case, as described above with reference to FIG. 5B, all of the calculated y values ​​are outside the display range of the currently specified y values, and the entire graph is not displayed (step S109; NO). For this reason, the control unit 13 displays, on the display unit 12, a screen P140 including a guide screen P141 arranged in front of the screen P120 displaying the graph so as to overlap with the screen P120, as shown in FIG. 6C, for example (step S111). By displaying the guide screen P141 so as to overlap with the screen P120 displaying the graph, the user can understand, for example, that the reason the graph is not displayed is not due to a delay in processing. The guide screen P141 includes a message P142 notifying the user that the graph of the function formula "y=x+11" will be drawn outside the graph display area P121, and a selection of display control contents. The guidance screen P141 in FIG. 6C displays three options for display control content: “View Window” (first display control content), which changes the graph display area P121 through user operation using the range specification screen P110; “Auto Zoom” (second display control content), which automatically changes the graph display area P121 based on the calculated y value; and “Cancel” (third display control content), which does not change the graph display area P121.

[0042] The user can select one of "View Window", "Auto Zoom", and "Cancel" in the guide screen P141. If "View Window" is selected (step S112; YES), the control unit 13 displays the range specification screen superimposed on the screen P120 (step S115) and accepts a change in the display range of the x-values ​​and y-values ​​(step S116). Then, when the user instructs to draw a graph, the control unit 13 determines that the range specification operation has ended (step S117). Based on the display range of the x-values ​​and y-values ​​at the end of the range specification operation, the control unit 13 changes the graph display area P121 and draws and displays the graph (step S118).

[0043] When the user selects the "Auto Zoom" selection item P143 (step S113; YES), the control unit 13 changes the graph display area P121 so that the minimum value of the calculated y values ​​becomes the minimum value of the display range of the y values, and the maximum value of the calculated y values ​​becomes the maximum value of the display range of the y values ​​(step S119). After that, the control unit 13 draws and displays a graph based on the x values ​​and the display range of the changed y values ​​(step S120). The solution (y value) of the function equation y=x+11 in -5≦x≦5 has a minimum value of 6 and a maximum value of 16. Therefore, the control unit 13 changes the display range of the y values ​​in the graph display area P121 to 6≦y≦16, as in the screen P120 of FIG. 6D, and draws and displays a graph of the function equation y=x+11.

[0044] Furthermore, if the user selects "Cancel" (step S114; YES), the control unit 13 makes the guide screen 141 non-displayable, and causes the display unit 12 to redisplay the screen P120 shown in Fig. 6B, i.e., the screen on which no graph is displayed in the graph display area P121. In this case, the user can change the display range of the graph display area P121 or its position in the xy plane and display the graph by, for example, operating the cursor keys 113 or pressing a predetermined key to display a range designation screen.

[0045] In this way, according to the scientific calculator 10 of the present embodiment, when the entire graph of an inputted functional formula passes outside the graph display area P121 and is not displayed on the display unit 12, the guidance screen P141 is displayed, thereby notifying the user of the reason (cause) why the graph is not displayed. Also, by presenting the user with options for measures (display control contents) for displaying the graph on the guidance screen P141, the user can easily know the reason why the graph is not displayed on the display unit 12 and the measures that can be taken to display the graph.

[0046] As a possible means for displaying a graph, by providing a means for changing the display range of x and y values ​​by user operation, the user can be given an opportunity to think about how to change the range to display the graph, and can learn more about graphs of function expressions. Also, as a possible means for displaying a graph, by providing a means for automatically changing the display range of y values ​​to the range from the minimum value to the maximum value of the calculated y values, the graph can be displayed on the display unit 12 with little effort.

[0047] In this embodiment, a function formula in which the value (x value) on the horizontal axis (x axis) of the graph is a variable and the value (y value) on the vertical axis (y axis) is a solution is given as an example, but the function formula is not limited to this. The function formula is not limited to a linear function, but may be a quadratic or higher function, or a constant function (zeroth order function). The function formula is not limited to a function formula with one variable, but may be a function formula with two or more variables. The function formula may be a function formula with the value (y value) on the vertical axis (y axis) of the graph as a variable and the value (x value) on the vertical axis (x axis) as a solution.

[0048] Furthermore, when the display range of y values ​​is automatically changed, for example, only one of the calculated minimum and maximum y values ​​may be specified as the end value of the display range of y values, and the display range (the maximum minus the minimum) may not be changed. For example, instead of the graph display area P121 illustrated in Fig. 6D, the graph may be displayed in a graph display area P121 in which the display range of y values ​​is changed from -2 < y < 4 to 6 < y < 12 or 10 < y < 16.

[0049] [Second embodiment] The electronic device 20 illustrated in Fig. 7 includes a touch panel display 21 that serves as both an input unit and a display unit, such as a tablet computer or a smartphone. The electronic device 20 of this embodiment may be the computer 30 illustrated in Fig. 8, may include the computer 30, or may be another information processing device that provides functions equivalent to those of the computer 30, and includes a processor 31, a main memory device 32, an auxiliary memory device 33, an input device 34, a display device 35, a communication device 36, a media reading / writing device 37, and an input / output interface 38 so as to be able to execute a calculator control program (emulator) that includes instructions related to the graph display process described above with reference to Figs. 3 and 4, and these hardware elements are connected to each other by a bus 39.

[0050] The processor 31 executes a calculator control program including a program portion corresponding to the graph display process described above with reference to Figs. 3 and 4, for example, to cause the computer 30 to operate as the scientific calculator 10 according to the first embodiment. The processor 31 may include one or more CPUs and other processors. The main storage device 32 and the auxiliary storage device 33 store the program executed by the processor 31, data referenced by the processor 31 executing the program, data generated by the processor 31, and the like. The input device 34 may be an input device (e.g., a keyboard, a mouse, etc.) that can be used as the key input unit 11 of the scientific calculator 10 according to the first embodiment. The display device 35 may be a dot-matrix display device that can be used as the display unit 12 of the scientific calculator 10 according to the first embodiment.

[0051] The communication device 36 may be a wireless communication device that can be used as the communication unit 16 of the scientific calculator 10 according to the first embodiment, or a communication device having a terminal to which a communication cable can be connected. The medium reading device 37 corresponds to the medium reading unit 15 of the scientific calculator 10 according to the first embodiment. The input / output interface 38 is, for example, a hardware interface having a terminal to which a transmission cable such as a USB cable can be connected. Note that some of the hardware elements exemplified above may be omitted from the computer 30 in FIG. 8 as long as it is possible to operate the computer 30 as a scientific calculator.

[0052] 7, the electronic device 20, which may be the computer 30, can display a calculator window 201 including a scientific calculator image 202 on the touch panel display 21. The scientific calculator image 202 includes a key input section on which a plurality of buttons (keys) are arranged, corresponding to the key input section 11 of the scientific calculator 10. When an operation of pressing a button on the key input section of the scientific calculator image 202 is performed, a function assigned to the pressed button is executed, and the execution result is displayed on the touch panel display 21. In other words, a user of the electronic device 20 can use the electronic device 20 as a scientific calculator by performing an operation of pressing a button (key) arranged on the key input section of the scientific calculator image 202 in the calculator window 201.

[0053] The electronic device 20 of this embodiment is not limited to one that can operate as a scientific calculator on its own, but may be one that can function as a scientific calculator by utilizing a Web system connected via a communication network such as the Internet.

[0054] FIG. 9 is a block diagram showing an example of the configuration of a learning system using a communication network. The learning system 40 illustrated in FIG. 9 may be a system for children, pupils, students, and other people who study using a scientific calculator, and includes an electronic device 20 and a Web system 50. The learning system 40 may include two or more electronic devices 20. The electronic device 20 includes a control unit 22, a storage unit 23, an input unit 24, a display unit 25, and a communication unit 26. The input unit 24 and the display unit 25 may be provided in the electronic device 20 as a touch panel display 21. The control unit 22 executes a program of a Web browser 27 stored in the storage unit 23, generates an HTTP request to be sent to the Web system 50, and displays a Web page in response to an HTTP response from the Web system 50. The communication unit 26 communicates wirelessly or wired with a communication device connected to a communication network 60 such as the Internet, and connects the electronic device 20 to the communication network 60.

[0055] The Web system 50 is a system that provides the function of a scientific calculator using the communication network 60, and includes a control unit 51, a storage unit 52, and a communication unit 53. The control unit 51 of the Web system 50 controls the operation of the Web system 50. For example, the control unit 51 performs processing in response to an HTTP request from the electronic device 20, generates a Web page in response to the result of the processing, and transmits the Web page to the electronic device 20 as an HTTP response. The processing in response to the HTTP request may be, for example, a process of generating a Web page including a scientific calculator image 202 (see FIG. 7), a process of generating a Web page that draws a graph of a functional formula and displays it on the electronic device 20, a process of generating a Web page that displays a guide screen P141 on the electronic device 20, and the like. The storage unit 52 stores scientific calculator content 54 provided to the electronic device 20 via the communication network 60, user data 55, and other data, programs, and the like (not shown). The scientific calculator content 54 may be a Web application that enables the electronic device 20 to be used as a scientific calculator, and includes a calculator control program (emulator). User data 551 of user A includes information such as user A's identification information, scientific calculator settings, and a function formula created by user A. User data 552 of user B includes information such as user B's identification information, scientific calculator settings, and a function formula created by user B. The scientific calculator settings include on / off of the display setting of the range specification screen described above, and settings of the display range of x and y values ​​on the range specification screen. Communication unit 53 communicates wirelessly or wired with a communication device connected to communication network 60, and connects Web system 50 to communication network 60.

[0056] 9, the calculation of the function formula can be performed by the Web system 50, and the electronic device 20 only needs to be capable of executing the Web browser 27. This makes it possible to avoid having the electronic device 20 perform high-load processing such as drawing and displaying a graph of a complex function formula, for example.

[0057] The present invention is not limited to the above-described embodiment, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way due to technological progress or other derived technology, the invention may be implemented using that method. Therefore, the claims cover all embodiments that may fall within the scope of the technical idea. [Explanation of symbols]

[0058] 10...Functional calculator, 11...Key input section, 12, 25...Display section, 13, 22, 51...Control section, 14, 23, 52...Memory section, 20...Electronic device, 24...Input section, 30...Computer, 31...Processor, 32...Main memory device, 34...Input device, 35...Display device, 36...Communication device, 40...Learning system, 50...Web system, P121...Graph display area, P141...Guidance screen

Claims

1. a control unit which, when a numerical value corresponding to a drawing range of a graph is input into a variable of a functional formula including at least one variable, and a graph of the functional formula is drawn and displayed on a display unit, when it is determined that the entirety of the drawing range graph passes outside a display range previously designated on the display unit, displays on the display unit a guide screen including a plurality of options for displaying the drawn graph within the display unit; An electronic device comprising:

2. The electronic device according to claim 1 , wherein the control unit causes the display unit to display the guidance screen so as to be superimposed on the display range.

3. The electronic device according to claim 2 , wherein the guidance screen is smaller than the display range, and at least a part of the display range is displayed on the display unit together with the guidance screen.

4. 2. The electronic device of claim 1, wherein the plurality of options include a first display control content that changes the display range in response to a user operation, and a second display control content that changes the display range in response to a numerical range set for the variable.

5. 2. The electronic device according to claim 1, wherein the control unit further causes the display unit to display a window including a scientific calculator screen for inputting the functional formula, and causes the display unit to draw a graph of the functional formula input by a user operation on the scientific calculator screen and display the graph on the display unit.

6. Electronic devices, When a numerical value corresponding to a drawing range of a graph is input to a variable of a functional formula including at least one variable, and the graph of the functional formula is drawn and displayed on a display unit, if it is determined that the entirety of the drawing range graph passes outside a display range previously specified on the display unit, a guide screen including a plurality of options for displaying the drawn graph within the display unit is displayed on the display unit. A display control method for performing processing.

7. A computer is an electronic device equipped with a display unit. A program for functioning as a control means for displaying, on the display unit, a guide screen including a plurality of options for displaying the drawn graph within the display unit when a numerical value corresponding to a drawing range of a graph is input into a variable of a function formula including at least one variable, and the graph of the function formula is drawn and displayed on the display unit and it is determined that the entire drawing range graph passes outside a display range previously specified on the display unit.

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