JPH063468Y2 - Small electronic calculator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a small electronic computer having a display designation function for a calculation result of a mathematical formula.

[Prior Art and its Problems] Some conventional small-sized electronic calculators input a mathematical expression including a variable, process the mathematical expression by inputting the variable, and display the result. For example, X = A + B + C is input, then A = 1, B = 2, C = 3 are input to perform calculation, and X = 6 is displayed on the display unit as the calculation result.

Further, there is a system in which a plurality of related mathematical expressions are input and a numerical value is substituted for a predetermined variable to perform a calculation process, and the calculation result is displayed only for those designated for display. For example, X = A + B + C Y = X + 1 PRINT Y A = 2, B = 3, C = 4 is input, and the calculation result Y = 10 is displayed on the display unit.

However, in the case of the former, since the calculation result of the input mathematical expression is displayed, the result of the intermediate calculation for obtaining Y, such as X in the latter, is also displayed, resulting in a display error. easy.

In the latter case, the display contents differ depending on the input position of the PRINT command. That is, when X = A + B + C PRINT Y Y = X + 1, “Y = 0” is displayed. In this way, if the input order is incorrect, the desired display content cannot be obtained. In addition, there is a problem that input errors are easy to make.

[Object of the Invention] The present invention has been made in view of the above points, and provides a small electronic calculator capable of displaying numerical data of a desired variable regardless of the input order of commands or mathematical expressions. With the goal.

[Summary of the Invention] The present invention instructs the display of the calculation result of an arbitrary mathematical expression in a small electronic computer that executes a calculation process by inputting a plurality of related mathematical expressions and substituting numerical values into predetermined variables. Means are provided, and the calculation result of the mathematical formula designated by this means is displayed.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, reference numeral 10 denotes a key input section, a numeral key 1, a function key 2, a character key 3, an IN key 4 for instructing data input to a mathematical expression memory, which will be described later, and a ":" indicating a mathematical expression delimiter.
A key 5, a CAL key 6 for designating a calculation mode, and an EXE key 7 for instructing execution of calculation are provided. Then, the data input from the key input unit 10 is sent to the control unit 11. The control unit 11 is composed of, for example, a ROM that stores various control commands, and an address is designated by an input from the key input unit 10 or the like to read control data. The control unit 11 is provided with an address bus AB
Also, the formula memory 12, the formula memory address storage unit 13, the variable data storage unit 14, the display variable data address storage unit 15, and the display memory 16 are connected via the data bus DB.
Further, a mathematical expression calculation section 17 and a non-display command symbol detection section 18 are connected to the data bus DB. The detection signal from the non-display command symbol detector 18 is sent to the controller 11. Also,
The control unit 11 gives a "+1" signal and a reset signal R to the addressing counter 19 which specifies the address of the formula memory. Further, a control end signal is sent from the control unit 11 to the display variable data address storage unit 15. And
The display data stored in the display memory 16 is sent to the display control unit 20 and displayed on the display unit 21.

Next, the operation of the above embodiment will be described. First, the mathematical expression input operation will be described with reference to the flowchart of FIG.
Now, assuming that the area S of the triangle is to be obtained using the Heron's formula, for example, first, the mathematical expression S = SQR {s * (s−a) * (s−b) * (s -C)}: s == (a + b + c) / 2 Input "IN". In the above equation, “==” indicates non-display, and the designation input is the non-display command symbol detection unit.
It is detected by 18, and the detection signal is sent to the control unit 11. The data key-input from the key input unit 10 is written in the display memory 16 via the control unit 11 as shown in step A1 of FIG. After inputting the formula data, I
When the N key 4 is operated, the control unit 11 detects the input of the IN key 4 in step A2 and transfers the key input data stored in the display memory 16 to the formula memory 12 as shown in step A3. As shown in FIG. 4 (a), the mathematical expressions delimited by ":" are stored in different areas.
In addition, the control unit 11 determines the mathematical expression memory 12 in step A4.
Of the variable data is stored in the formula memory address storage unit 13 and the variable data is
The variable data storage unit 14 is sequentially stored as shown in FIG. After that, in the next step A6, it is judged whether or not the stored variable data includes left-side data. If there is no left-side data, the process is ended. If there is left-side data in the variable data, step A7 is executed. Proceed to. In step A7, it is determined whether or not there is a non-display instruction symbol for the left side data determined in step A6. If all the left side data have non-display instruction symbols, the process ends. However, if there is at least one left-side data without a non-display instruction symbol, the process proceeds to step A8, and the address data of the variable data storage unit 14 in which the left-side data without the non-display instruction symbol is stored is changed to the display variable data address. It is stored in the storage unit 15. In the above equation, "S" before ":" and "s" after ":" are left side data, which are detected in step A6 and proceed to step A7. In step A7, it is determined whether or not there are non-display command symbols for "S" and "s". In “s” after “:”, there are two “=” and there are non-display instruction symbols, but in “S” before “:” there is only one “=” and there is no non-display instruction symbol. In step A8, the address data of the variable data storage unit 14 in which "S" is stored is set to the fourth value.
It is stored in the display variable data address storage unit 15 as shown in FIG. Further, since there is a non-display instruction symbol for "s", address data is not written.

Next, the numerical operation processing operation will be described with reference to the flowchart of FIG. First, a known numerical value is substituted by the key input unit 10. For example, if a = 6: b = 3: c = 7 "EXE" is input, the above numerical values "6, 3, 7" are converted into "a," in the variable data storage unit 14 as shown in step B1 of FIG.
It is input to the area corresponding to "b, c". The control unit 11
When the input of the numerical data to the variable data storage unit 14 is completed, the process proceeds to step B2 and the addressing counter 19 is reset. In this state, the control unit 11 reads the first formula S = SQR {s * (s−a) * (s = b) * (s−c)} stored in the formula memory 12 as shown in step B3. In step B4, it is determined whether the calculation end flag F is "1". In this case, since the calculation end flag F is "0", the process proceeds to step B6 to determine whether the calculation is possible. That is, the variable "s" on the right side,
It is determined whether or not numerical values are substituted for “a”, “b”, and “c”. In this case, since the numerical value is not substituted for "s", the process proceeds to step B6 and the addressing counter 19
Is incremented by 1, and then the process returns to step B3. As the addressing counter 19 is incremented by "+1" as described above, the following formula s = (a + b + c) / 2 is read from the formula memory 12. Then, in step B4, it is determined whether or not the calculation end flag F is "1", but since the flag F is "0", the process proceeds to step B5. Then, in step B5, it is determined whether or not the calculation is possible. Since numerical values are respectively assigned to the variables "a", "b", and "c" on the right side, the process proceeds to step B7 to calculate the mathematical expression. A mathematical operation is performed by the unit 17, and the result of the operation is “s =
8 ”. When this mathematical operation is completed, in step B8, as shown in FIG.
“1” is written in the operation end flag F at the position corresponding to (a + b + c) / 2 ”, and at the step B9, the result of the above mathematical operation is“ s = 8 ”as shown in FIG. 4 (b).
Is written in the position corresponding to “s” in the variable data storage unit 14. Then, in step B10, it is determined whether or not the processing for all the mathematical expressions has been completed, and if not completed, the processing returns to step B2.

In this step B2, the addressing counter 19 is reset, and then in step B3, the first formula S = SQR {s * (s−a) * (s−b) * (s−c)} is read from the formula memory 12. In step B5, it is determined whether calculation is possible. At this point, since numerical values are assigned to all the variables and the calculation can be performed, the process proceeds to step B7 to perform the mathematical calculation, and the calculation result "S = 8.9447191" is obtained. When this mathematical operation is completed, "1" is written in the operation end flag F at the position corresponding to the mathematical expression in step B8, and the result "S" of the mathematical expression is calculated in step B9 as shown in FIG. 4 (b). = 8.94
427191 ”is written to the variable data storage unit 14 at a position corresponding to“ S ”. After that, in step B10, the calculation end flag F of the formula memory 12 is judged, and if all formulas have been calculated, the process proceeds to step B12, where the variable is determined by the address data stored in the formula memory address storage unit 13. The address of the data storage unit 14 is designated, and in step B12 the variable name "S" and the numerical value "8.9442.
7191 "is read into the display memory 16 and displayed on the display unit 21 as shown in FIG. 6 (a). As described above, only the area S of the triangle can be displayed and the display of the variable s can be prohibited.

Further, when it is desired to display the calculation result of the variable s together with the area S of the triangle, S = SQR {s * (s−a) * (s−b) * (s−c)}: s from the key input unit 10 = (A + b + c) / 2 The numerical operation data is input by operating the "IN" key, and the non-display command symbol is not input. When the non-display command symbol is not input as described above, it is determined that there is no non-display command symbol for both left side data "S" and "s" in step A7 of FIG. 2, and the process proceeds to step A8. Then, in this step A8, as shown in FIGS. 5B and 5C, the address data for “S” and “s” in the variable data storage unit 14 is written in the display variable data address storage unit 15.

After that, by inputting numerical values for the variables "a", "b", and "c", the mathematical expression calculation shown in FIG. 3 is started. When the mathematical operation is completed, the variable data storage unit is operated according to the address data stored in the display variable data address storage unit 15 in step B11 of FIG.
From 14, the variable names “S” and “s” and their numerical value “8.94”
427191 ”and“ 8 ”are read to the display memory 16,
As shown in FIG. 6 (b), the display section 21 displays S = 8.942471191 s = 8.

In addition, in the above-described embodiment, the symbol indicating the non-display is "=
Although “=” is used, various other methods such as “#” symbol can be considered.

Moreover, you may make it specify the variable which wants to be displayed like the conventional program calculator. For example, when obtaining a solution of Y = aX ² + bX + c, PRINT = {X1, X2}: X1 = (− b + SQR (D)) / (2 * a): X2 = (− b−SQR (D)) as a key input. ) / (2 * a): D = -b ² -4 * a * c. In this case, PRINT = {X1, X
2} is read, X1 and X2 are input to the variable data storage unit 14 and the address data of the variable data storage unit 14 are input to the display variable data address storage unit 15, and then X
When inputting the variables of the formulas 1 = ..., X2 = ..., D = ..., To the variable data storage unit 14, the display variable data address storage unit
No address data is input to 15. Variables to be displayed can be specified by the above processing.

[Effects of the Invention] As described in detail above, according to the present invention, a plurality of related mathematical expressions are input, and a small electronic computer that executes arithmetic processing by substituting a numerical value into a predetermined variable can calculate an arbitrary mathematical expression. Since it is arranged to display the calculation result of the mathematical formula designated by the above-mentioned means when the calculation processing is completed, the calculation result is displayed regardless of the input order of the command or the mathematical formula. You can display the numerical data of the variable you want.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a block diagram showing a circuit configuration, FIG. 2 is a flow chart showing a mathematical expression input operation, FIG. 3 is a flow chart showing a mathematical expression operation, FIG. FIG. 5 is a diagram showing a data storage state of various memories, and FIG. 6 is a diagram showing a display state example. 10 ... Key input unit, 11 ... Control unit, 12 ... Formula memory, 13 ... Formula memory address storage unit, 14 ... Variable data storage unit, 15 ...
Display variable data address storage unit, 16 ... Display memory,
17 ... Math operation unit, 18 ... Non-display instruction symbol detection unit, 19 ... Addressing counter, 20 ... Display control unit, 21 ... Display unit.

Claims (1)

[Scope of utility model registration request] 1. Input means for inputting a plurality of mathematical expressions including variables, instruction means for instructing whether or not to display a calculation result for the mathematical expression input by the input means, and a plurality of input means for inputting the mathematical expressions. Mathematical expression storage means for storing the mathematical expression of ## EQU1 ##, substitution means for substituting numerical values for the variables of the plurality of mathematical expressions, arithmetic means for substituting numerical values by the substitution means, and arithmetic operations of the plural mathematical expressions, and A small electronic computer comprising: a display control means for displaying only the calculation result of a mathematical formula instructed to display the calculation result when the calculation is completed.