GIS (Geographic Information System)-based point-line-plane dynamic plotting drawing method

Abstract

The invention relates to a dynamic plotting and drawing method, in particular to a point-line-plane dynamic plotting and drawing method based on a GIS (Geographic Information System). The method comprises the following steps: 1, judging an animation type and a plotting type of a plotting object, and calling a corresponding control point calculation method; 2, calculating the total length of the dynamically plotted contour line in the plotting object; 3, segmenting the contour line according to unit time to obtain a segmented control point array; 4, based on the segmented control point array, calculating to obtain an array subscript of the control point array at the current time; 5, acquiring an updated array based on the array subscript, and updating the updated array as a data source of the plotting object; and 6, after the data source of the plotting object is updated, playing is carried out according to the animation type and the plotting type of the plotting object, and drawing of the dynamic plotting is completed. According to the method, dynamic GIS plotting is introduced, so that the display effect of the GIS situation map is more vivid and visual, the current situation can be more accurately conveyed, and the intuition of the GIS situation map is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a dynamic plotting method, in particular to a point-line-surface dynamic plotting method based on GIS. BACKGROUND

[0002] Traditional GIS plotting is mostly static symbol plotting. This plotting method is characterized by the use of fixed and standardized symbols, such as specific graphics or colors representing different types of deployment, movement direction, etc. Although these symbols are carefully designed to reflect the actual situation to some extent, they are static in nature and have obvious limitations in interactivity and display effect. Traditional GIS plotting is usually more suitable for presentation in the form of paper maps.

[0003] Traditional GIS plotting mainly relies on static symbol plotting to display GIS situation maps. This method, although with a long history, has met the basic needs of situation display to some extent, but its limitations in display effect have become increasingly apparent, mainly in the following aspects:

[0004] 1. Insufficient information display:

[0005] Static symbol plotting is not sufficient in expressing complex situation information. For example, it is difficult to intuitively display the sequence of multiple movement processes and other information through static symbols. Static symbols can only provide limited situation information and cannot meet users' needs for comprehensive, in-depth, and intuitive understanding of GIS situations.

[0006] 2. Lack of interactivity:

[0007] Static symbol plotting lacks interactivity with users. Users can only obtain information through visual means and cannot perform operations such as rewinding, advancing, and displaying all situations. This lack of interactivity limits users' in-depth exploration and understanding of information and reduces the efficiency and quality of decision-making.

[0008] 3. Lack of intuitiveness and readability:

[0009] Static symbol plotting also lacks intuitiveness and readability. Since static symbols lack dynamic effects and visual guidance, users may have difficulty quickly and accurately capturing key information.

[0010] In summary, the static symbol display method of traditional GIS plotting has obvious limitations in information display, interactivity, and intuitiveness and readability. These limitations limit its application effectiveness and value. Therefore, we need to explore more advanced, efficient, and intuitive GIS plotting methods to meet the needs of GIS situation map information display and command decision-making. SUMMARY

[0011] The present application aims at solving the technical problems of the prior art GIS plotting, which mainly relies on static symbol plotting to display the GIS situation map, and which is insufficient in information display, lacks in interactivity, intuition and readability, and provides a point-line-surface dynamic plotting method based on GIS.

[0012] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0013] A point-line-surface dynamic plotting method based on GIS, which is characterized by comprising the following steps:

[0014] Step 1: importing the data of the plotting object, judging the animation type and the plotting type of the plotting object in sequence, and calling the corresponding control point calculation method;

[0015] Step 2: calculating the total length of the contour line of the dynamic plotting in the plotting object by using the corresponding control point calculation method;

[0016] Step 3: dividing the contour line according to the unit time based on the total length of the contour line and the animation duration, so as to obtain the control point array after division, i.e. the animation distance in the unit time;

[0017] Step 4: based on the control point array after division, the array index of the control point array at the current time is calculated by setting the callback function of the frame animation;

[0018] The array index of the control point array refers to the index-th control point in the control point array;

[0019] Step 5: based on the array index, the index-th control point and the control points before it in the control point array are obtained to form an update array, and the update array is used as the data source of the plotting object for updating;

[0020] Step 6: after the data source of the plotting object is updated, the animation type and the plotting type of the plotting object are played to complete the plotting of the dynamic plotting.

[0021] Further, step 3 is specifically as follows:

[0022] Step 3.1: the distance between two adjacent control points on the dynamic plotting contour line is calculated in a loop;

[0023] Step 3.2: it is judged whether the distance is less than the animation distance in the unit time, if yes, the two adjacent control points are added to the return array; if not, the distance between the two adjacent control points is further divided into segments each having a length of the animation distance in the unit time, and the two adjacent control points are added to the return array, which is the control point array after division.

[0024] Further, step 4 is specifically:

[0025] By setting the callback function of the frame animation, the formula: {[current time - animation start playing time] / animation duration playing time} * length of the control point array is used to calculate the array index of the control point array under the current time;

[0026] The length of the control point array refers to the number of control points in the array.

[0027] Further, in step 1, the animation type includes growth, flashing, rotation and scaling;

[0028] The plotting type includes arc, ellipse, curve, curved surface, bow, sector, gathering, thin arrow, transfer direction, swallow tail transfer direction, team transfer defense line, circle, pincer strike, broken line, polygon, rectangle, point and text.

[0029] Further, in step 6, when playing according to the animation type and plotting type of the plotting object, the playing of the plotting object can be paused by the plotting animation control unit.

[0030] Further, in step 1, the data of the plotting object is imported by the plotting data import unit;

[0031] In step 6, after completing the drawing of dynamic plotting, the updated plotting object data can be exported by the plotting data export unit as needed.

[0032] The beneficial effects of the present application are:

[0033] 1. Improve the display effect: the introduction of dynamic GIS plotting makes the display effect of GIS situation map more vivid and intuitive, and can more accurately convey the current situation, improving the intuitiveness of GIS situation map.

[0034] 2. Improve decision efficiency: through GIS dynamic plotting and animation playing control, users can more intuitively understand the situation information, thereby making decisions more quickly, improving the efficiency and accuracy of command.

[0035] 3. Easy to operate and maintain: through the import and export functions of GIS plotting data, users can easily customize and modify GIS plotting according to actual needs, reducing the operation difficulty and maintenance cost of the system. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a flowchart of an embodiment of the present application;

[0037] Figure 2 is a system structure diagram of GIS in an embodiment of the present application. DETAILED DESCRIPTION

[0038] To make the purposes, advantages and features of the present application clearer, a GIS-based point-line-surface dynamic plotting method is further described in detail below in combination with the drawings and specific embodiments. The advantages and features of the present application will be clearer according to the following detailed description.

[0039] Introduction of GIS

[0040] In a narrow sense, GIS is a computer system for collecting, storing, operating, analyzing, displaying and outputting geographic spatial data.

[0041] The main functions of GIS include:

[0042] 1) Data management: can organize and store various types of geographic information data, including maps, satellite images, survey data, etc.

[0043] 2) Spatial analysis: can perform various spatial analyses on geographic information, such as distance calculation, overlay analysis, network analysis, etc.

[0044] 3) Visualization: visually display geographic information through maps and graphics to help users understand the spatial distribution and relationship of data.

[0045] In the field of flood control and disaster relief applications, GIS mainly performs data visualization display and spatial analysis functions.

[0046] 2. Introduction of GIS plotting

[0047] GIS plotting is to describe various situations such as danger zones, gathering points, transfer routes, etc. on maps or electronic sand tables by using specific graphic symbols. Its purpose is to provide intuitive situation information to help users make more accurate decisions and command.

[0048] 1) Danger zone: mark the area threatened by mountain flood disaster or other natural disasters on the situation.

[0049] 2) Gathering point: a gathering point refers to an area where people are required to gather or gather after an emergency or disaster occurs.

[0050] 3) Transfer route: a transfer route is a pre-planned path for personnel evacuation before an emergency or disaster occurs.

[0051] 3. GeoJSON

[0052] GeoJSON is an open standard format that extends the JSON format for representing, storing, and exchanging geospatial data. Due to the ease of understanding and processing of the JSON format, GeoJSON is particularly suitable for map applications in web and JavaScript environments. Common application scenarios and examples include:

[0053] 1) Map display: Using GeoJSON format data can display various geographic features on the map, such as cities, roads, rivers, etc. For example, you can use JavaScript map libraries such as Leaflet to load and display GeoJSON data.

[0054] 2) Spatial analysis: GeoJSON supports various analysis operations on geospatial data, such as calculating distance, area, intersection, union, etc. These analysis operations can help users better understand and utilize geographic data.

[0055] 3) Data exchange: As a common geospatial data format, GeoJSON facilitates data exchange and sharing between different systems and platforms. For example, you can import GeoJSON data into GIS for analysis and processing.

[0056] Reference Figure 1 , the embodiment of the point-line-surface dynamic plotting method based on GIS specifically includes the following steps:

[0057] Step 1, first plot the data import unit to import the plotting object data in GeoJSON format, see Figure 2 , the plotting data import / export function is an important part of GIS dynamic plotting. It allows users to import external plotting data or export GIS plotting data to external files. These data can include plotting locations, properties, animation effects, etc. Through the plotting data import / export function, users can easily exchange and share data with other systems, improving data utilization and system interoperability.

[0058] Then determine the animation type and plotting type of the plotting object in turn, see Figure 2 , the GIS plotting animation can set the animation function of the GIS plotting object, including growth, flashing, rotation, scaling, etc. Animation types support setting animation duration, loop playback times, etc.

[0059] Reference Figure 2 , the GIS dynamic plotting function also provides a series of tool class operations to support users to more efficiently perform GIS plotting. Including plotting type definition, plotting animation type definition and acquisition, plotting animation parameter setting, etc.

[0060] The GIS plot can allow users to draw various point, line, and surface markers on the map according to actual needs, such as danger zones, gathering points, and transfer routes. These plots can be customized according to different needs, including color, shape, size, and other attributes. Specifically, the plot types include arc, ellipse, curve, curved surface, bow, sector, gathering place, thin arrow, transfer direction, swallow tail transfer direction, team transfer defense line, circle, pincer strike, polyline, polygon, rectangle, marker, and text.

[0061] According to the animation type and plot type of the judged plot object, the corresponding control point calculation method is called.

[0062] Different control point calculation methods are described in Figure 2 , and the basic function modules involved include the following:

[0063] 1) DOM operation

[0064] DOM (Document Object Model) in JavaScript is a standard programming interface for representing and manipulating HTML and XML documents. It allows developers to access and modify the content, structure, and style of web pages programmatically. In dynamic GIS plotting, the DOM operation function encapsulates common DOM operations.

[0065] 2) Distance calculation

[0066] Distance calculation is crucial in GIS dynamic plotting, as it involves accurately measuring the distance between two or more points in geographic space.

[0067] 3) Center point calculation

[0068] Center point calculation refers to determining the center position of a geographic area or geometric shape. In GIS dynamic plotting, center point calculation is used to determine the center point of the plot. The present invention provides various center point calculation methods, such as centroid calculation and geometric center calculation, to meet different application requirements.

[0069] 4) Curve point calculation

[0070] Curve point calculation refers to calculating the position of a point on a given curve based on specific conditions. In GIS dynamic plotting, curve point calculation is used to determine the moving track and travel route of the plot. The present invention provides various curve point calculation methods, such as interpolation and curve fitting, to adapt to different curve shapes and precision requirements.

[0071] 5) Angle conversion

[0072] Angle conversion converts the angle information in geospatial into other forms or units. In GIS dynamic plotting, angle conversion is used to determine the direction of plotting, calculate the orientation of plotting, or evaluate the angle of plotting, etc. The present application provides various angle conversion methods, such as the conversion between latitude and longitude and spherical coordinates, the calculation of azimuth angle, etc., to meet different application requirements.

[0073] 6) Coordinate system conversion

[0074] Coordinate system conversion is the conversion of geospatial data from one coordinate system to another. In GIS dynamic plotting, coordinate system conversion is used to realize data sharing and unified map projection between different coordinate systems.

[0075] Step 2, calculate the total length of the contour line of the dynamic plot in the plot object using the corresponding control point calculation method.

[0076] Step 3, according to the total length of the contour line and the animation duration, divide the contour line by unit time to obtain the segmented control point array, and the number of control point groups is the animation distance in unit time. For example, the control point group number is [a, b, c, d, e], and the animation distance is the number of control points in the control point group number, which is 5.

[0077] Step 3.1, loop to calculate the distance between two adjacent control points on the dynamic plot contour line.

[0078] Step 3.2, judge whether the distance is less than the animation distance in unit time, if yes, add the two adjacent control points to the returned array; if not, continue to divide the distance between the two adjacent control points into each segment with a length of the animation distance in unit time, and add the two adjacent control points to the returned array; the returned array is the segmented control point array.

[0079] Step 4, based on the segmented control point array, set the callback function of the frame animation, and calculate the array index of the control point array at the current time; the array index of the control point array refers to the index th control point in the control point array.

[0080] For example, if the array index is 3, it refers to c in the control point group number.

[0081] Through the callback function of the browser window.requestAnimationFrame frame animation, the formula {[current time - animation start playing time] / animation duration playing time}*length of control point array is used to calculate the array index of the control point array at the current time; the length of the control point array refers to the number of control points in the array.

[0082] Step 5, based on the array index, the indexth control point and the control points before it in the control point array are obtained to form an update array, and the update array is taken as the data source of the plotting object for updating.

[0083] Step 6, after the data source of the plotting object is updated, the plotting object is played according to the animation type and the plotting type of the plotting object, and in the playing process of the plotting object, the playing of the plotting object can be selectively paused as needed by the plotting animation control unit, and the dynamic plotting is completed. The updated plotting object data is exported by the plotting data export unit.

Claims

1. A GIS-based point-line-surface dynamic plotting method, characterized in that, The method comprises the following steps: Step 1, importing data of a plotting object, sequentially judging an animation type and a plotting type of the plotting object, and calling a corresponding control point calculation method; Step 2, calculating a total length of a contour line of dynamic plotting in the plotting object by using the corresponding control point calculation method; Step 3, according to the total length of the contour line and a set animation duration, dividing the contour line according to a unit time to obtain a segmented control point array, that is, an animation distance in the unit time; Step 4, based on the segmented control point array, a callback function of a frame animation is set to calculate an array index of the control point array at a current time; The array index of the control point array refers to an index of a control point in the control point array; Step 5, based on the array index of the control point array at the current time, an index control point and control points before the index control point in the control point array are obtained to form an update array, and the update array is used as a data source of the plotting object for updating; Step 6, after the data source of the plotting object is updated, the plotting object is played according to the animation type and the plotting type, and the dynamic plotting is completed.

2. The point-line-surface dynamic plotting method based on GIS according to claim 1, characterized in that, Step 3 specifically comprises: Step 3.1, the distance between two adjacent control points on the dynamic plotting contour line is calculated; Step 3.2, whether the distance is less than the animation distance in the unit time is judged, if yes, the two adjacent control points are added to a return array, if not, the distance between the two adjacent control points is further divided into segments each having a length of the animation distance in the unit time, and the two adjacent control points are added to the return array, and the return array is the segmented control point array.

3. The point-line-surface dynamic plotting method based on GIS according to claim 1 or 2, characterized in that, Step 4 specifically comprises: The array index of the control point array at the current time is calculated by setting the callback function of the frame animation and using a formula: {[current time-animation start playing time] / animation duration playing time}*length of the control point array; The length of the control point array refers to the number of control points in the array.

4. The point-line-surface dynamic plotting method based on GIS according to claim 3, wherein: In step 1, the animation type comprises growth, flashing, rotation and scaling; The plotting type comprises arc line, ellipse, curve, curved surface, bow, sector, gathering place, thin arrow, transfer direction, swallow tail transfer direction, subunit transfer direction, circle, pincer strike, broken line, polygon, rectangle, mark point and text.

5. The point-line-surface dynamic plotting method based on GIS according to claim 1, wherein: In step 6, when the plotting object is played according to the animation type and the plotting type, the playing of the plotting object can be paused by a plotting animation control unit.

6. The point-line-surface dynamic plotting method based on GIS according to claim 1, wherein: In step 1, the data of the plotting object is imported by a plotting data import unit; In step 6, after the dynamic plotting is completed, the updated plotting object data can be exported by a plotting data export unit according to needs.

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