JP2798082B2 - Graph display control device and graph display control method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graph display control device and a graph display control method for displaying a graph based on function formula data. 2. Description of the Related Art Heretofore, small electronic calculators capable of displaying graphs corresponding to functional equation data have been considered. In this type of computer, when a certain function expression y = f (x) is displayed in a graph, the independent variable x and the function expression y = f (x) are sequentially keyed in, and the value of the dependent variable y is calculated each time. It is.
When displaying a graph, the entire graph is displayed on a fixed coordinate axis such that the center of the display screen becomes the origin.
The scale of the coordinate axes is also fixed. [0003] However, in the case of the above-mentioned conventional computer, the range of the graph to be displayed cannot be freely specified because the coordinate axes and the scales thereof are fixed. It was very inconvenient. The object of the present invention is to
The purpose is to allow the range of the graph to be displayed to be freely specified, and to display the graph of the specified range and the coordinate axes with the scales together. According to a first aspect of the present invention, there is provided a graph display control apparatus for storing function expression data for displaying a graph, and storing the function expression data in the function expression storage means. A range designating means for designating an arbitrary range among the graphs indicated by the function formula data, and a graph corresponding to the range designated by the range designating means, into the function formula data stored in the function formula storage means. Graph calculating means for calculating based on the coordinates, coordinate axis calculating means for calculating a coordinate axis corresponding to the range specified by the range specifying means, scale adding means for applying a scale to the coordinate axes calculated by the coordinate axis calculating means, Display control means for controlling to display together the coordinate axes graduated by graduation adding means and the graph calculated by the graph calculating means, It is provided with a configuration. According to a third aspect of the present invention, a graph display control method stores function formula data, designates an arbitrary range in a graph represented by the stored function formula data, and corresponds to the designated range. The calculated graph is calculated based on the stored function formula data, the coordinate axes corresponding to the specified range are calculated, and the calculated coordinate axes are scaled,
The coordinate system with the scale and the calculated graph are controlled to be displayed together. According to these inventions, among the graphs represented by the function formula data, a graph corresponding to an arbitrary range is calculated based on the function formula data, and a coordinate axis corresponding to the arbitrary range is calculated. A scale is attached to the calculated coordinate axis, and the coordinate axis with the scale and the graph are displayed together. An embodiment of a graph display control device and a graph display control method according to the present invention will be described below with reference to the drawings, taking a small electronic computer as an example. FIG. 1 is a circuit diagram of a small electronic computer having a graph display function. In the figure, a memory unit 3 constitutes a function expression storage unit for storing function expression data for displaying a graph. The range key 1E constitutes a range designating unit for designating an arbitrary range in the graph represented by the function formula data stored in the memory unit 3. The calculation unit 5 constitutes a graph calculation means for calculating a graph corresponding to the range specified by the range key 1E based on the function formula data stored in the memory unit 3, and also specifies the graph specified by the range key 1E. A coordinate axis calculating means for calculating a coordinate axis corresponding to the range is configured. The control unit 2 includes a display control unit that performs control so as to display the scale calculated by the calculation unit 5 together with the scale calculation unit that scales the coordinate axes calculated by the calculation unit 5 and the graph calculated by the calculation unit 5. Configure. Hereinafter, a detailed description will be given including other configurations of this circuit diagram. The key input unit 1 includes a numeric keypad 1A, a function key 1B, a function key 1C for inputting a function calculation expression, a graph key 1D for designating a graph display mode of the function expression, and a function expression. Range key 1E for designating the input mode of each range data of variables X and Y included in, and E for instructing execution of function calculation and the like
At least an XE (execute) key 1F is provided, and a signal from each key is sent to the control unit 2 and processed. The control unit 2 comprises a ROM (Read Only Memory) for storing a program for controlling all operations of the computer, and sends various control signals to a memory unit 3, an execution pointer 4, an operation unit 5, and a display buffer unit 6. give. The memory unit 3 is composed of a RAM (random access memory), and has an A register 3A, a B register 3B, and a pointer register 3C in which the execution pointer set by the control unit 2 is temporarily saved to the execution pointer 4 when performing a function operation. X ₀ register 3 in which previous coordinates (x ₀ , y ₀ ) for graph display at the time of execution of a function operation are set, respectively
D, y ₀ register 3E, x register 3F, y register 3G in which the current coordinates (x, y) are set, x _min register 3H, x _{max in which} the minimum value and the maximum value of the range of the variable x are set, respectively Register 3I, the minimum value of the range of the variable y,
The y _min register 3J and the y _max register 3K in which the maximum values are set, respectively, and the x _SCL register 3 used at the time of graduation processing
It has an L, y _SCL register 3M, an x _memo register 3N, and a y _memo register 3P in which the size of each dot of coordinates (x, y) for displaying a graph is written. Each data of the function formula input from the key input unit 1 is written to each address of the formula buffer 7 pointed to by the execution pointer 4, and then read into the arithmetic unit 5. The operation unit 5 executes the operation of the function expression from the expression buffer 7 using the registers 3A to 3P of the memory unit 3 under the control of the control unit 2. The arithmetic unit 5 reads the data for the graph display, the coordinate axes and the scale display from the memory unit 3 at the time of execution of the function operation, sends the data to the graph display buffer 6A in the display buffer unit 6, and performs normal numerical display and the like. Sometimes data for that is sent to the text display buffer 6B, and the display data is sent to the display unit 8 to display a graph or a numerical value. The display unit 8 is composed of, for example, a liquid crystal display device, and has a matrix type dot display body (coordinate points) of 96 dots in the X direction and 64 dots in the Y direction to display data. Next, the operation of the above embodiment will be described with reference to FIGS. 2 to 12 by taking the case where the operation of the function formula Y = -SINX (1) is performed and the result is displayed in a graph as an example. . In this case, the range key 1E and the numeric keypad 1A of the key input unit 1 are preliminarily operated and the x _min registers 3H, x as shown in FIG.
_The data of the minimum value and the maximum value of the range for the variable x, for example, -180 and 180 are preset in the _max register 3I, and the minimum value of the change range for the variable y is similarly stored in the y _min register 3J and the y _max register 3K. And each data of the maximum value, for example, -2, 2 and x _SCL register 3L, y _SCL
Each of the registers 3M stores scale data, for example, 90,
0.5 is preset. Next, when the function expression of the above expression (1) is input by operating the graph key 1D, the function key 1C, the function key 1B, the numeric keypad 1A, and the EXE key 1F, the addresses 0 to 4 of the expression buffer 7 are displayed as shown in FIG. As shown in FIG. 3, each data of the function expression of the expression (1) is written by being addressed by the execution pointer 4. The data "END" of the execution pointer "4" is END code data written at the time of operating the EXE key 1F. In accordance with the operations in the flowcharts of FIGS. 7 to 12, the calculation unit 5 performs the function calculation of the expression (1) and the calculation for displaying the coordinate axes and the scale, and the resulting graph is shown in FIG.
Is displayed on the display unit 8 as shown in FIG. That is, in the main flow of FIG. 7, when a graph command is input, first, an operation for determining the presence or absence of data in the graph display buffer 6A is executed. , Y _memo register 3
P is cleared, and then the Y coordinate calculation is performed in step G3. Next, in step G4, the y register 3
It is determined whether the data in G is “FF”. Thus,
Since it is now NO, the process proceeds to step G5, where the coordinates (0,
A line is drawn between two points y) and (95, y). In the example of FIG. 5, the y coordinate is “32” from the calculation of FIG. Next, the x _memo register 3N is cleared in step G6, then the X coordinate calculation is executed in step G7, and then the process proceeds to step G8 where the data in the x register 3F is set to "F
F "is determined, and since NO is determined, the process proceeds to Step G9 to draw a line between two points of coordinates (x, 0) and (x, 63). In the example of FIG. 5, the X coordinate is “4” from the calculation of FIG.
8 ". Then, the process proceeds to step G10 to calculate the scale by performing the scale process shown in FIG. 10, and then proceeds to step G11 to perform the graph process shown in FIG. 12, and then proceeds to step G12 to display the graph screen. In step G4, if the data in the y register 3G is "FF", it is an error, and the process proceeds to step G6. Step G8
When the data in the x register 3F is "FF", it is an error, and the process proceeds to Step G10. Next, the calculation of the Y coordinate in step G3 will be described with reference to the flowchart of FIG. First,
In step Y1, the calculation of the expression for _obtaining the value of the Y coordinate shown is executed according to the data set in the y _memo register 3P, the y _min register 3J, and the y _max register 3K, and the resulting data is stored in the y register 3G. Set. Next, in step Y2, the set data is converted into an integer by the rounding method, and then, in step Y3
In, it is determined whether or not the converted data is smaller than the minimum position coordinate “0” in the Y coordinate direction. The YES is hexadecimal data "80 _H" is set to the y register 3G proceeds to step Y4 when the (step Y4), ending.
The hexadecimal data “80 _H ” has an 8-bit configuration as shown in FIG. 4 for the data configuration of the y register 3G and the like.
This is for an ANGER / UNDER RANGE flag. In this case, a flag "1" indicating UNDER RANGE is written in the flag bit. The minimum coordinate data "0" is written in the lower 7 bits of the y register 3G. On the other hand, if NO in step Y3, the process further proceeds to step Y5, where the integer data is converted to Y
It is determined whether or not it is larger than the maximum position coordinate "63" in the coordinate direction. If YES, the process proceeds to step Y6 to write hexadecimal data "BF _H " in the y register 3G, and OVER
A flag “1” indicating RANGE and the maximum coordinate data “6”
"3" is written. Further, if NO is determined in the step Y5, the effect of the current Y coordinate calculation is not over the range, so that the process ends. Next, the X coordinate calculation in step G7 will be described with reference to the flowchart in FIG. First, step X
In step 1, the operation of the equation shown is executed using the data in the x _memo register 3N, the data set in the x _min register 3H, and the data set in the x _max register 3I, and the result is set in the x register 3F. Next, at step X2, the data in the x register 3F is converted into an integer, and then the process proceeds to step X3 to determine whether the data is smaller than "0". If YES, the process proceeds to step X4, where the same processing as in step Y4 is performed and x register 3
A flag of UNDER RANGE is set in F, and minimum coordinate data "0" is written. On the other hand, if NO in step X3, the process proceeds to step X5 to determine whether or not the data in the x register 3F is greater than "95". If YES, the process proceeds to step X6 and the OVER RANGE is stored in the x register 3F. Hexadecimal data D indicating the flag and the maximum coordinate data "95"
Write F _H and end. Further, in step X5, when the data in the x register 3F is smaller than "95", the range is not over and the current X coordinate calculation ends. Next, the operation of the graduation process in step G10 will be described with reference to the flowcharts of FIGS.
First, in step S1 of FIG. 10, it is determined whether or not the data in the x _SCL register 3L is "0". In this example, since the data is "90" as shown in FIG. It is determined whether the Y coordinate is “63” or less. In the example of FIG. 5, the result is YES, and the Y coordinate is OVER R
Since it is not an angle, the flow advances to step S4 to determine whether or not the Y coordinate is equal to or less than the center coordinate “32”. In the example of FIG. 5 in which the Y coordinate is “32”, the X coordinate axis is located below the center of the display unit 8. The process proceeds to step S5, and the Y coordinate is incremented by +1.
Then, it is set in the y register 3G. As a result, X
For the axis, as shown in FIG. 6 (B) or (C), the scale is applied to the upper side of the X axis, that is, toward the larger space at the center of the screen. . Next, in step S7, the coordinate data in the x register 3F is saved in the A register 3A, and then the calculation (-180/90) in step S8 is performed to set "-2" in the B register 3B. In step S9, the data is rounded. Next, in step S10, data "90" in the x _SCL register 3L is multiplied by data "-2" in the B register 3B, and the result is obtained. -18
"0" is set in the x _memo register 3N. Then, in step S11, the X coordinate calculation shown in FIG. 9 is performed. As a result, the X coordinate “0” is obtained in step X1. Then, in step S12, the X coordinate is "DF
_It is determined whether or not the X coordinate is “ _H ”, and if NO at this time, it is not a calculation error and the process proceeds to step S14, and the X coordinate is “80H”
It is determined whether or not this is the case. Since it is now NO, the process proceeds to step S15, and the point of the X coordinate is plotted. Then, step S1
In 6, the data in the B register 3B is incremented by 1 to "-1", and the process returns to step S10. Next, in step S10, the data of the x _memo register 3N becomes "-90". Then, in step S11, the X coordinate becomes “23, 75” by the calculation in step X1, which is converted to an integer, and the X coordinate becomes “24”. Then, steps S12, S14,
S15 is executed, and then, in step S16, the data of the B register 3B becomes "0". Next, step S10
Returning, the data of the x _memo register 3N becomes “0”, then the X coordinate becomes “48” by the calculation in step S11, and then the steps S12, S14, S1
5, S16 is executed, and the data of the B register 3B becomes "1". Then, returning to step S10, the data of the x _memo register 3N becomes "+90". Then, in the X coordinate calculation in step S11, the X coordinate becomes “71”. Next, steps S12, S14, S15 and S16 are executed, and the data of the B register 3B becomes "2". Then, returning to step S10, the data of the x _memo register 3N becomes "180". Then, in the X coordinate calculation in step S11, the X coordinate becomes "95", and
2, S14, S15 and S16 are executed, and the B register 3
B data “3” is set. Next, step S10
As a result, the data of the x _memo register 3N becomes "27
0 ”, and then in the X coordinate calculation of step S11,
Since the X coordinate becomes "119" and becomes OVER RANGE, YES is obtained in step X5, and data "DF _H " is set in the x register 3F. As a result, step S is executed.
In step S12, the answer is YES, the process proceeds to step S13, and the data saved in the A register 3A is returned to the x register 3F. Then, the process proceeds to step S17 in FIG. That is, four scales are set for the X axis by the data “90” in the _xSCL register 3L. Next, in step S17, since the data of the y _SCL register 3M is "0.5" and not 0 in the present example, the flow advances to step S18 to determine whether or not the X coordinate of the x register 3F is "95" or less. Thus, in the example of FIG.
In step S20, the process proceeds to step S20 to check whether the Y axis is on the right or left of the center of the display unit 8. In the example of FIG. 5, the X coordinate data on the left side is “48”.
Since it is below, the process proceeds to step S21, and the X coordinate data of the Y axis is incremented by one. As a result, as shown in FIG.
The axis is graduated to the right, i.e., toward the larger space in the center of the screen. Thereafter, steps S23 to S30, which are processing steps similar to steps S8 to S16 described above, are repeatedly executed to perform a calculation for obtaining a scale for the Y coordinate. On the other hand, if NO in step S2, the Y coordinate exceeds the maximum coordinate, and the flow advances to step S3 to store the data in the y register 3G and the data "3F _H " (63). And the y register 3
The upper two bits of G are cleared, and the process proceeds to step S7. Then, steps S7 to S16 are executed, and graduation processing for the X axis is performed. As a result, as shown in FIG.
With respect to the axis, a scale is provided at the outer edge (side) of the display screen of the display unit 8 below the X axis, that is, toward the center of the screen. On the other hand, if the answer is NO in step S4, the process proceeds to step S6, where the data in the y register 3G is
1 and proceed to step S7. In this case, the X coordinate axis is located above the center of the display unit 8,
As shown in FIG. 6 (A), the scale is attached to the X coordinate axis toward the lower side, that is, toward the wide direction of the screen space. Further, if NO in step S18, the X coordinate exceeds the maximum coordinate, so that step S19 is executed.
The logical product of the data of the x register 3F and the data “5F _H ” is obtained, and the upper 1 bit is cleared. Thereafter, steps S23 to S30 are executed, and graduation processing for the Y axis is performed. As a result, the scale for the Y coordinate is shown in FIG.
As shown in (C), the outer edge of the display screen of the display unit 8 is attached to the center of the screen. Furthermore, if the result of the above step S20 is NO, it means that the Y axis is located to the right of the center of the display unit 8. In step S22, the X coordinate data of the Y axis is decremented by one.
It is set in the x register 3F, and the following step S23
The calculation for marking the Y axis in S30 is performed. As a result, as shown in FIG. 6B, the scale is provided toward the left side of the Y axis, that is, toward the wide space at the center of the screen of the display unit 8. The display example of FIG. 6D is an example in which both the calculated coordinate axes are out of the display screen area.
The coordinate of the axis exceeds the maximum coordinate and the coordinate of the Y axis exceeds the minimum coordinate. Next, the graph processing in step G11 will be described with reference to the flowchart in FIG. That is, in step M1, the head pointer of execution pointer 4 (address "0") together with the transferred retracted in the pointer register 3C, y ₀ Register Data "FF" (hexadecimal code) to 3E are written, further The x register 3F is cleared. Next, at step M2, the x _min register 3
H, using the data preset in the x _max register 3I and the data in the x register, which is now “0,” the arithmetic operation of the illustrated equation is executed, and the data indicating the size of one dot of the variable X ( Now, the data "-180" preset in the x _min register 3H is obtained, and it is set in the x _memo register 3N. In other words, the coordinates of the first display dot in the X coordinate direction are thereby obtained. Next, at step M3, the pointer register 3
The address "0" saved in C is returned to the execution pointer 4, and the next step M4 executes the function operation of the equation (1) in the equation buffer 7 from the addresses "0" to "4". And the first answer is y _memo register 3P
Is set to Next, at step M5, it is determined whether or not the answer is an arithmetic error. If YES, the process proceeds to step M6, where a hexadecimal code "FF" indicating error data is written to the y register 3G, and then the process proceeds to step M9.
Proceed to. On the other hand, if NO in step M5, steps M7 and M8 are executed, and FIG.
According to the flow shown in FIG. 2, the Y coordinate calculation (in this case, calculation for obtaining the coordinates of the first display dot in the Y coordinate direction) and the data of the display dot of the (X, Y) first coordinate are stored in the graph display buffer. 6A, and a process of lighting and displaying on the display unit 8 is executed. Then, the process proceeds to step M9.
In step M9 from x register 3F x ₀ register 3D
In contrast, the current operation result data is transferred and saved as the previous operation result data.
_The current operation data is transferred and saved to the ₀ register 3E as the previous operation data. Next, in step M10, the data of the x register 3F is incremented by one, and in step M11, the result data is set to "9" which is larger than the maximum display coordinate "95" in the X direction.
6 "or more, and in this case, naturally, the determination is NO and the process returns to step M2. The coordinates of the second and lower (X, Y) coordinates are obtained by repeating steps M2 to M11. When the answer is YES in step M11, the calculation is terminated, and as a result, the graph shown in FIG. Next, referring to the flowchart of FIG.
The DRAW process in step M8 will be described. First, Step D1 In y ₀ Register 3E upper digit (4bit)
Is determined to be data "F" indicating out of range. If YES, this flow ends, and the display operation for this coordinate is not executed. On the other hand, if NO, the process proceeds to step D2, where it is determined whether or not the upper digit data of the y register 3G is data "F" indicating out of range. If YES, display of these coordinate points is prohibited. On the other hand, if NO, the process proceeds to step D3, where the coordinates (x ₀ , y ₀ ), (x, y) based on the data set in the x ₀ register 3E, the y ₀ register 3F, the x register 3F, and the y register 3G, respectively. The graph display operation for connecting the points between them is executed, and the process ends. In the above embodiment, the scale is provided only on one side of the X-axis and the Y-axis, but it may be provided on both sides. According to the present invention, a graph corresponding to an arbitrary range among the graphs represented by the function expression data is calculated based on the function expression data, and the coordinate axes corresponding to the arbitrary range are set. Calculate, attach a scale to the calculated coordinate axis, and display the coordinate axis with the scale and the graph together, so you can freely specify the range of the graph to be displayed, and the displayed graph is The relationship between the coordinate axes and the scales attached to the coordinate axes makes it very easy to see.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing a configuration of an embodiment of the present invention. FIG. 2 is a diagram showing a graph obtained by calculating an input function expression. FIG. 3 is a diagram showing a relationship between a function expression and an execution pointer 4 in FIG. 2; FIG. 4 is a diagram showing a data configuration in a register. FIG. 5 is a diagram showing a display example of range data and scale data input by keys. FIG. 6 is a diagram showing a display example of coordinate axes and scales. FIG. 7 is a flowchart of a graph instruction. FIG. 8 is a flowchart of a Y coordinate calculation. FIG. 9 is a flowchart of an X coordinate calculation. FIG. 10 is a flowchart of a scale process. FIG. 11 is a flowchart of a graduation process following FIG. 10; FIG. 12 is a flowchart of a graph process. FIG. 13 is a flowchart of a DRAW process in FIG. 12; [Description of symbols] 1A numeric keypad 1B function keys 1C function keys 1D graph key 1E range key 1F EXE (execute) key 2 control unit 3C pointer register 3D x ₀ Register 3E y ₀ Register 3F x Register 3G y register 3H x _min register 3I x _max register 3J y _min register 3K y _max register 3L x _scl register _{3My scl} register 3N x _memo register 3P y _memo register 4 execution pointer 5 operation unit 6A graph display buffer 7 equation buffer 8 display unit

Continuation of front page (56) References JP-A-52-116050 (JP, A) JP-A-53-92643 (JP, A) JP-A-54-51752 (JP, A) JP-A-57-147769 (JP) , A) JP-A-58-97762 (JP, A) JP-A-59-45589 (JP, A) JP-A-59-47638 (JP, A) Fully open 1980-14,881 (JP, U) Fully open 60-42645 (JP, U) Fumihiko Kudo et al. All of PC-8801 graphics ASCII Publishing Chapter 3 Issued 1st edition, 3rd print on December 20, 1982 1st edition (58) Fields surveyed (Int. Cl. ⁶ , DB name) ) G06F 15/02

Claims (1)

(57) [Claims] Function expression storage means for storing function expression data for displaying a graph; range designation means for designating an arbitrary range in a graph represented by the function expression data stored in the function expression storage means; A graph calculating means for calculating a graph corresponding to the range specified by the specifying means based on the function formula data stored in the function formula storing means; and a coordinate axis corresponding to the range specified by the range specifying means Coordinate axis calculating means, scale adding means for giving a scale to the coordinate axis calculated by the coordinate axis calculating means, and the coordinate axes marked by the scale adding means and the graph calculated by the graph calculating means. And a display control means for controlling the display so as to be displayed together. 2. The scale adding means includes space scale adding means for giving a scale to the coordinate axes toward a wider space among the spaces divided by the coordinate axes calculated by the coordinate axis calculating means. Item 2. The graph display control device according to Item 1. 3. Storing the function formula data, specifying an arbitrary range in the graph indicated by the stored function formula data, calculating a graph corresponding to the specified range based on the stored function formula data, A coordinate axis corresponding to the specified range is calculated, a scale is attached to the calculated coordinate axis, and control is performed so that the coordinate axis with the scale and the calculated graph are displayed together. And a graph display control method. 4. 4. The graph display control method according to claim 3, wherein, when the scale is provided, the scale is provided for the coordinate axis toward a wider space among the spaces divided by the calculated coordinate axes.