JPS61275961A - Electronic calculator with graphic display function - Google Patents

Abstract

PURPOSE:To easily see a graph by displaying at least divisions even when coordinate axes cannot be displayed by displaying a graph adding divisions to an outer edge section of a display screen nearer to the coordinate axes when the calculated coordinate axes are situated outside a display area of the screen based on a variable of a prescribed function. CONSTITUTION:An arithmetic part 5 executes the operation of a function expression from a numerical expression buffer 7 under a control of a control part 2 by using respective registers 3A-3P of a memory section 3. The arithmetic part 5 reads the data for displaying a graph, coordinate axes and its divisions during performing the operation of the function from the memory part 3 to feed to a graph display butter part 6A in a display buffer section 6. When an ordinary numerical value display or the like is carried out, the data therefor is fed to a text display buffer 6B and its display data is fed to a display part 7 and the display of the graph or the numerical value or the like is carried out. When the calculated coordinate axes are outside an area of the display screen, the position of the divisions is displayed at an end section of the display screen nearer to the coordinate axes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention 1] The present invention relates to a small electronic calculator having a function of displaying a functional formula in a graph.

[Prior Art] Conventionally, small electronic calculators that can display graphs corresponding to functional formulas have been considered. In this type of calculator, when displaying a certain functional formula y=f(x) as a graph, the independent variable It is.

This calculator displays only the graph of the functional formula on the display.

[Problem with Prior Art 1] However, in the case of the above-mentioned conventional calculator, the coordinate axes were not displayed, so it was difficult to know the roots of the displayed graph and the number of roots, which was very inconvenient.

[Object of the Invention] It is an object of the present invention to provide a small electronic calculator having a graph display function that can display coordinate axes and make graphs easier to see.

[Key Points of the Invention] Coordinate axes (X-axis, Y-axis,
The position of the axis) and its scale position are calculated, and when the calculated coordinate axis is outside the area of the display screen, the scale position is displayed at the edge of the display screen near the coordinate axis. .

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram of a small electronic calculator equipped with a graph display function. In FIG.

Function key IB, function key IC1 for inputting the function formula, graph key ID for specifying the graph display mode of the function formula, range key specifying the input mode for each range data of variables X and Y included in the function formula EXE (execution) key IF for issuing execution instructions for IE, function calculations, etc.
are provided at least, and signals from each key are sent to the control unit 2 and processed.

The control section 2 consists of a ROM (read only memory) that stores programs for controlling all operations of this computer, and provides various control signals to the memory section 3, execution pointer 4, calculation section 5, and display buffer section 6.

The memory unit 3 consists of a RAM (random access memory), and includes an A register 3A, a B register 3B, and a pointer register 3C1 in which the execution pointer set by the control unit 2 in the execution pointer 4 when performing a function operation is temporarily saved.
The previous coordinates (xo
, 7o) are set respectively in the Xo register 3D.
, yo register 3E, X register 3F, Y register 3G, where the current coordinates (x, y) are set, respectively, X5in register 3H, x,, register, where the minimum and maximum values of the range of variable X are set, respectively. 3I, 7sin register 3 where the minimum and maximum values of the range of variable y are set respectively.
J, Vsax register 3K, x sct register 3L, VSCL register 3M used for scale processing, V
Each has a memo register 3P.

Each data of the function formula inputted from the key input unit 1 is written to each address of the formula buffer 7 indicated by the execution pointer 4, and then read into the calculation unit 5.

The arithmetic unit 5 calculates the function formula from the formula buffer 7 through each of the registers 3A of the memory unit 3 under the control of the control unit 2.
~ Execute using 3P. When executing a function calculation, the calculation unit 5 reads data for displaying the graph, coordinate axes, and scale from the memory unit 3, sends it to the graph display buffer 6A in the display buffer unit 6, and performs normal numerical display, etc. Sometimes, data for this purpose is sent to the text display buffer 6B, and the display data is sent to the display section 7, where graphs, numerical values, etc. are displayed.

The display unit 8 consists of a liquid crystal display device, for example, and has 96 pixels in the X direction.
Data is displayed using a matrix type dot display (coordinate points) of 64 dots in the Y direction.

Next, the operation of the above embodiment will be explained by taking as an example the case where the function formula % formula % (1) is calculated and the result is displayed in a graph, and with reference to FIGS. 2 to 12.

In this case, the range key IE and numeric keypad I of the key manual section 1 are
By manipulating A in advance, as shown in Figure 5, each data of the minimum value and maximum value of the range for variable
0 and also 7 sin registers 3J, V
Similarly, in the sax register 3K, preset each data of the minimum value and maximum value of the change range for the variable y, for example, -2, 2, and in the xsct register 3L and YSCL register 3M, scale data, for example, 90.0.5. I'll keep it.

Next, the function formula of equation (1) above is input to the graph key ID, function key IC, function key IB, numeric keypad LA, and EX.
When input by operating the E key IF, each data of the function formula of formula (1) is written to addresses 0 to 4 of the formula buffer 7, addressed by the execution pointer 4, as shown in FIG. . In addition, the data rEN of execution pointer "4"
D" is END code data written when the EXE key IF is operated. Then, according to the operations according to the flowcharts of FIGS. 7 to 12, the calculation unit 5 (
1) Functional calculation of the equation and calculation for displaying its coordinate axis and its scale are performed, and the resulting graph is displayed on the display section 8 as shown in Fig. 2. In other words, the main flow shown in Fig. 7 , when a graph command is input, first, an operation to determine the presence or absence of data in the graph display buffer 6A is executed, and since there is currently no data, the process proceeds to step G2, the ymeso register 3P is cleared, and the process proceeds to step G2. Y coordinate calculation is executed by G3. Next, in step G4, it is determined whether the data in the y register 3G is rFF'J. Now, the answer is NO, so proceed to step G5, and set the coordinates (Oly),
Draw a line between the two points (95, y). In the example shown in FIG. 5, the y coordinate is "32" from the calculation shown in FIG. 8, and x mem is determined by step G6 at the 0th order.

Clear the register 3N, then execute the X coordinate calculation in step G7, then proceed to step G8, judge whether the data in the X register 3F is rFFJ, and if NO, proceed to step G9, calculate the coordinate (X ,0),(x,
63). In addition, in the example of Figure 5, draw a line between the two points of
From the calculation in the figure, the X coordinate is "48".

Next, the process proceeds to step GIO, where the scale processing shown in FIG. 10 is performed to calculate the scale, the process proceeds to step Gll, where the graph processing shown in FIG. 11 is performed, and the process proceeds to step G12, where a graph screen is displayed.

Note that in step G4, if the data in the y register 3G is rFFJ, it is an error, so step G6
Proceed to. Further, in step G8, if the data in the X register 3F is rFFJ, it is an error, and the process proceeds to step GIO.

Next, the Y coordinate calculation in step G3 will be explained with reference to the flowchart of FIG.

First, in step Yl, the formula for calculating the value of the Y coordinate shown in the figure is calculated using '7 memo register 3F, 7sin
The execution is performed according to the data set in the registers 3J, 7aax and 3K, respectively, and the resulting data is set in the y register 3H.

Next, in step Y2, the set data is rounded off to an integer, and then in step Y3,
The integer data is the minimum position coordinate in the Y coordinate direction.
It is determined whether or not the value is smaller than "0". When the answer is YES, the process advances to step Y4 and the hexadecimal data r is stored in the y register 3G.
80oJ is set (step Y4) and the process ends. In addition,
The meaning of this hexadecimal data r80HJ is y register 3G
As shown in Figure 4, the data structure is an 8-bit structure, and the most significant bit is 0VERRANG.
It is for the E/UNDERRANGE flag, and in this case, the flag bit indicates “UNDERRANGE”.
This means that 1'' has been written. Also, y register 3G
Minimum coordinate data rQJ is written in the lower 7 bits of .

On the other hand, if NO in step Y3, the process further advances to step Y5, where it is determined whether the above-mentioned integer data is larger than the maximum position coordinate "63" in the Y coordinate direction, and YES.
When , proceed to step Y6 and set 16 to y register 3G.
The decimal data rBF+J is written, and the flag "1" indicating 0VERRANGE and the maximum cut-off data "63" are written and the writing is completed. Further, if NO in step Y5, the result of the current Y coordinate calculation is not over the range, and the process ends.

Next, according to the flowchart of FIG. 9, the step G7 is
The calculation of the X coordinate will be explained.

First, in step x1, the calculation of the formula shown in the figure is executed using the data in the x5eso register 3N, the data set in the Xain register 3H, and the X@ax register 3I, and the result is set in the X register 3F. .

Next, in step x2, the data in the X register 3F is converted into an integer, and the process then proceeds to step x3, where it is determined whether the data is smaller than rQJ. So, YES
If so, proceed to step x4, perform the same process as step Y4 above, and write tJNDERRANGE to the X register 3F.
Set the flag and write the minimum coordinate data "0".

On the other hand, if the result in step x3 is No, the process proceeds to step x5, and it is determined whether the data in the The process ends by writing hexadecimal data DFH indicating coordinate data "95".

Further, in step x5, if the data in the X register 3F is smaller than "95", the current X coordinate calculation ends because the range is not over.

Next, the operation of the scale processing in step G10 will be explained using the flowcharts shown in FIGS. 10(1) and 10(2).

First, in step S1, it is determined whether the data in the X SCL register 3L is "0" or not.
As shown in the figure, since it is "90", the process proceeds to step S2, and it is determined whether the current Y coordinate is "63" or less. Therefore, in the example shown in Figure 5, the answer is YES, and the Y coordinate is 0VERRA.
Since it is not NGE, the process proceeds to step S4, and it is determined whether or not the Y coordinate is less than or equal to the center coordinate "32". In the example of FIG. Since it is located at step S5, the Y coordinate is incremented by 1 and it is set in the y register 3G. As a result, for the X-axis, as shown in Figure 6 (B) or (C), the scale is placed above the X-axis, that is, toward the wider space in the center of the screen. will be done.

Next, in step S7, the coordinate data in the X register 3F is saved to the A register 3A, and then the calculation in step S8 (
-180÷90) and set "-2" in the B register 3B. Further, in step S9, the data is rounded, and then in step S10, xsct register 3
Data “90” in L and data “-” in B register 3B
2", and the result obtained is r-180",
. Set in register 3N. And step Sll
Accordingly, 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 312, it is determined whether or not the above-mentioned X coordinate is rDFhJ, and if it is now NO, it is not a calculation error, so the process proceeds to step S14, and it is determined whether or not the X coordinate is r80++j. Proceed to step S15 and
Plot a point in coordinates. Then, in step S16, the data in the B register 3B is incremented by 1 to become "-1", and the process returns to step S10.

Then, in step 310, the x semo register 3N
The data becomes r-904. And step Sll
Then, the X coordinate is r due to the calculation in step Xi.
23.75J, convert it into an integer, the X coordinate becomes "24", and step S12, Si2.5
15 is executed, and then in step 31B, the data in the B register 3B becomes "0". Then, the process returns to step 510, where the data in the X@emo register 3N becomes rOJ, and then, by the calculation in step Sll, the X coordinate is "
48'' and then step S12. S14.515
, 316 is executed, and the data in B register 3B becomes "1".
Then, return to step SIO x sea. The data in the register 3N becomes "+90", and in the X coordinate calculation in step Sll, the X coordinate becomes "71" in steps S12, S14, S15. S16 is executed, and the data in the B register 3B becomes "2", and the process returns to step 510, where the data in the x memo register 3N becomes "180". Then, in the X coordinate calculation in step S11, the X coordinate becomes "95", and in step S11, the
12.514, S15, and S16 are executed, and data "3" is set in B register 3B.0th step S
Xmen by running 10. The data in register 3N becomes "270", and then in the X coordinate calculation in step 511, the X coordinate becomes rl19J-7'0VERRANGE? , As a result, the result is YES in step S12, and the result is YES in step S13.
The process proceeds to step S17, where the data saved in the A register 3A is returned to the X register 3F, and the process proceeds to step S17, where a scale process for the Y axis begins. That is, for the X axis, X5CL
The four locations are marked with data "90" in the register 3L.

Next, in step S17, since the data in the ysct register 3M is rO, 5J and not O in the present example, the process proceeds to step 518, where it is determined whether the X coordinate of the X register 3F is "95" or less, and the fifth In the example in the figure, it is YES,
Proceeding to step S20, it is checked whether the Y-axis is to the right or left of the center of the display section 8. In the example of FIG. 5, it is on the left side, and the X coordinate data of the Y axis is less than "48", so the process advances to step S21, and the X coordinate data of the Y axis is +
Do 1.

As a result, as shown in Figure 6 (A), for the Y axis,
A scale is provided on the right side, that is, towards the wider space at the center of the screen. Thereafter, steps S23 to S30, which are processing steps similar to steps S8 to 316 described above, are repeatedly executed to calculate a scale for the Y coordinate.

On the other hand, if the result in step S2 is No, the Y coordinate exceeds its maximum coordinate, so step S3
Proceed to y register 3G data and data r3FoJ
(63), clears the upper two bits of the y register 3G, and proceeds to step S7.

Then, steps S7 to 516 are executed to perform scale processing for the X-axis.As a result, as shown in FIG. 6(D), for the X-axis, the outer edge (side) of the display screen of the display unit 8
A scale is placed below the X-axis, that is, toward the center of the screen.

On the other hand, if NO in step S4, step S
6, the data in the y register 3G is decremented by 1, and the process proceeds to step S7.In this case, the X coordinate axis is located above the center of the display section 8, and the As shown in FIG. 6(A), the scale is directed downward, that is, toward the widest direction of the screen space.

Further, if NO is determined in step S18, the X coordinate exceeds its maximum coordinate, so the process proceeds to step S19, and the data in the X register 3F is ANDed with the data "5FHJ", and the upper 1 bit is cleared.Then, the following steps are performed. Step 3
Steps 23 to S30 are executed to perform scale processing on the Y axis.

As a result, the scale for the Y coordinate is placed on the outer edge of the display screen of the display unit 8 toward the center of the screen, as shown in FIG. 6(C).

Furthermore, if the result in step S20 is No, it means that the Y-axis is on the right side of the center of the display section 8, and step S22
, the X coordinate data of the Y axis is decremented by 1, it is set in the X register 3F, and the calculation for attaching a scale to the Y axis in steps S23 to 530 is performed. As a result, as shown in FIG.
As shown in B), with respect to the Y axis, the left side, that is, the display section 8
A scale is placed toward a wide space in the center of the screen.

The display example in Figure 6 (D) is an example in which both of the calculated coordinate axes are outside the display screen area, especially the X-axis coordinate exceeds its maximum coordinate, and the Y-axis coordinate exceeds its minimum coordinate. This shows an example that goes beyond.

Next, according to the flowchart of FIG. 11, the above step Gll
Explain the graph processing of

That is, in step M1, the first pointer (address "0") of the execution pointer 4 is transferred and saved to the pointer register 3C, and data rF is stored in the yo register 3E.
F” (1B base code) is written, and then the X register 3
F is cleared.

Next, in step M2, Xain register 3H1
The calculation of the formula shown in the figure is executed using the data preset in the X, □ register 3I and the data in the X register, which is currently "0", and data indicating the size of one dot of the variable X is obtained. (Currently, the data "-180J" preset in the Find the coordinates of.

Next, in step M3, the address rOJ saved in the pointer register 3C is returned to the execution pointer 4, and in the next step M4, "4" is returned from this address rQJ.
The functional operation of formula (1) in the formula buffer 7 up to 0 is executed, and the first answer is set to 7 memo register 3P.Next, in step M5, it is determined whether the answer is an operation error or not. If the result is YES, the process advances to step M6, where a hexadecimal code rFFJ indicating error data is written to the y register 3G, and then the process advances to step M9.

On the other hand, when the result in step M5 is NO, steps M7 and M8 are executed, and the Y coordinate calculation (in this case, the coordinate of the first display dot in the Y coordinate direction) is performed according to the flow shown in FIGS. ) and its (x, y
) is sent to the graph display buffer 6A, and a process of lighting the display dot on the display section 8 is executed. The process then proceeds to step M9.

In step M9, from X register 3F to XO register 3D
In contrast, the current calculation result data is transferred and saved as the previous calculation result data, and the same is true.

The current calculation data is transferred and saved from the y register 3G to the Yo register 3E as the previous calculation data.

Next, in step MIO, the data in X register 3F is +1
In addition, in step Mll, it is determined whether the resulting data is greater than "96" which is larger than the maximum display coordinate "95" in the X direction, and in the current case, the heat output is NO and step M2 is performed. Returning to step M1.1, each coordinate of (X, Y) from the second onwards is executed by repeating steps M2 to Mll, and when YES is obtained in step M1.1, the calculation is finished and as a result, the A graph shown in FIG. 2 is displayed on the display section 8.

Next, with reference to chart 70 in FIG. 12, the DRAW processing in step M8 will be described.

First, in step D1, it is determined whether the upper digit of the y0 register 3E is data rFJ indicating that it is out of range.
When it is ES, this flow ends and no display operation is performed for this coordinate.

On the other hand, when the answer is NO, the process proceeds to step D2, where it is determined whether the data in the upper digits (4 bits) of the y register 3G is data rFJ indicating outside the range, and when the answer is YES, display of this coordinate point is prohibited. . On the other hand, when the answer is No, the process proceeds to step D3, where the coordinates (xo, yo
), (x, y) is executed, and the graph display operation is completed.

In the above embodiment, the scales were attached only to one side of the X-axis and the Y-axis, but they may be attached to both sides.

[Effects of the Invention] As explained above, the present invention is a calculator that calculates and displays a graph of a function, which calculates and displays coordinate axes (X-axis, Y-axis) and their scales based on preset variables of the function. is calculated, and when the calculated coordinate axes are outside the display area of the screen, the graph is displayed with the scale attached to the outer edge (side) of the display screen that is closer to the coordinate axes. Since it is a small electronic calculator equipped with a graph display function, it has the advantage that even when the coordinate axes cannot be displayed, only the scale is displayed, making the graph very easy to read.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a diagram showing a graph obtained by calculating an input function formula, and FIG. 3 is a diagram showing the relationship between the above function formula and the execution pointer 4. figure,
Figure 4 is a data configuration diagram of the XO register 3D to y register 3G, etc., Figure 5 is a diagram of a display example of range data and scale data input manually, Figure 6 is a diagram of a display example of coordinate axes and scales, and Figure 7 is a diagram of a display example of the coordinate axes and scales. 12 through 12 are flowcharts for displaying graphs, coordinate axes, and scales. IA...Numeric keypad, IB...Function key, IC...Function key, ID...
...Graph key. lE...Range key, IF...EXE
(Execution) key, 2...Control unit, 3C...
...Pointer register, 3D...Xo register, 3E...yo register, 3F...
・X register, 3G...y register, 3H...
...Xoin register, 3I...x s
ax register, 3J...Vain register, 3K...V sax register, 3L...
...X SCL register, 3M...Y S
CL register, 3N...x memo register, 3P...V memo register, 4...
...Execution pointer, 5... Arithmetic unit, 6A...
...Graph display buffer, 7...Math buffer, 8...Display section. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 9 Figure 11 CA convex □ Figure 12

Claims (1)

[Claims] A small electronic calculator equipped with the function of displaying graphs on a matrix type display section, which includes an input means for inputting a function formula and range data indicating the range of each variable included in the function formula input by this input means. a range input means for inputting; a range data storage means for storing the range data;
The graph display data of the function formula is calculated from the range data of each variable and the function formula, and the position and scale position of the coordinate axes with respect to the display graph are calculated according to the range data, and the calculated coordinate axes are A graph display function characterized by comprising means for automatically displaying the scale position on the matrix type display section along with the graph at the end of the display screen near the coordinate axes when the scale position is outside the area of the display screen. A small electronic calculator with