diff --git a/src/mod/applications/mod_expr/expreval.html b/src/mod/applications/mod_expr/expreval.html index f66d327c2d..d6cade26c2 100644 --- a/src/mod/applications/mod_expr/expreval.html +++ b/src/mod/applications/mod_expr/expreval.html @@ -1,1334 +1,1334 @@ - - -ExprEval Library - - - - -
-

ExprEval Library

-
-
- -
-

Contents

-

- -

-
- -
-

Introduction

-
-

ExprEval Help document. This document is probably full of - bugs and mispellings. I may get around to proofreading - it later.

-

ExprEval is a C based expression evaluation library. - It is entirely C based, but can be used in C++ programs - as well.. The source code is provided for the library - so that it can be recompiled for the specific system - or compiler.

-

ExprEval makes adding mathematical expression support to - an application easy. It takes an expression string and - parses it, and then it can evaluate it over and over. - This library also has support for functions, constants, - and variables. All of these items are stored in - seperate lists so they can be shared among expressions or - they can be private to a single expression or any mix and - match. It is up to the developer how to link them together. - You can also create your own custom functions.

-
-
- -
-

License

-
-

This library is licensed under the - ExprEval License. -

-
-
- -
-

Expression Syntax

-
-

Expressions have pretty much the same syntax as they - would have on paper, with the following exceptions: -

-

-

More than one expression may be contained within an expression string. - As shown above, each expression must end with a semicolon, even if - only one expression is in the string. The value of an expression - string is the value of the last expression in the string.
- Examlples: -

-

-

Some functions may take reference parameters. These parameters are - references to other variables. You can mix reference parameters - with normal parameters. The order of the normal parameters must - remain the same and the order of the reference parameters must - remain the same.
- Examples: -

-

-

Expressions may also be nested with parenthesis.
- Examples: -

-

-

Expressions may also have whitespace characters and comments. - Whitespace characters such as newlines, linefeeds, carriage - returns, spaces, and tabs are ignored. Comments begin with - the pound sign '#' and end at the end of the line.
- Example: -

-

-

If a variable is used in an expression, but that variable does not exist, - it is considered zero. If it does exist then its value is used instead. -

-
-
- -
-

Using ExprEval in an Application

-
-

Using ExprEval in an application can be a little difficult. - You generally follow these steps: -

- You can manipulate the lists in any order after their creation. - However, functions are translated during the parse, so after - parsing an expression, manipulating the function list will make - no change to an expression. Variables and constants can be - manipulated after a parse to change the result of an expression. - However, you must add any constants to be used by an expression - to the constant list BEFORE parsing the expression, - otherwise it will be seen as a variable. Applications can change - both variables and constants, however the expression can only - change variables. Expressions may NOT assign to a constant - and expressions may NOT use constants as a reference parameter.

-

Function, variable, and constant list example: -

-

-

Expression object example: -

-

-

Expression parse example: -

-

-

Expression evaluation example: -

-

-

Free the expression object and lists example: -

-

-
-
- -
-

Fast Variable Access

-
-

A new feature in ExprEval is fast variable access. This - is simply a technique of quickly accessing variables - by directly accessing their memory locations instead - of using the value list functions. Fast variable access - is always used internally in ExprEval. You must - NOT clear a variable list until after all expressions - using it are completely finished evaluating. Then you - must reparse the expressions before using them again. - The reason is simple. When fast variable access is used, - the variable memory location is directly accessed If you - clear a variable list and then evaluate an expression, - it will access invalid memory.

-

You can also use fast variable access in you application - to dramatically speed up loops. This is accomplished as - follows: -

-

-
-
- -
-

Using the Internal Functions and Constants

-
-

To use the internal functions, they must first be initialized - into a function list with exprFuncListInit. To use the - internal constants, they must first be initialized into a - value list with exprValListInit. For a list of the - internal functions and constants, see the application - help template file: ExprTmpl.html - You may use this file in your own applications so you don't - have to write a detail on the functions in ExprEval. All - you have to do is add you own functions and constants to - the file if there are any. -

-
- -
-

Creating Custom Functions

-
-

Custom functions can be created for use by the library. - This is how a function should look -

- - obj is a pointer to the expression object that called - the function, nodes is a pointer to an array of nodes - that are the parameters of this function, nodecount is - the number of items in the array (the number of parameters), - refs is an array of pointers to referenced variables, - refcount is the number of referenced variables, - and val is a pointer to a variable to recieve the result - of the function. The function should return an error value - indicating the error status of the function. -

-

Solving a function typically goes as follows: -

-

-

Example: -

-

-

In order to use a custom function, it must be added to - a function list before the expression is parsed by using - exprFuncListAdd

-
-
- -
-

Reference

-
-

Headers: -

-

-

Defines: -

-

-

Objects: -

-

-

Types: -

-

-

Version information functions: -

-

-

Function list functions: -

-

-

Value list functions: -

-

-

Expression functions: -

-

-

Some useful functions -

-

-
-
- -
-

Compiling the ExprEval library

-

Compiling the ExprEval library is pretty simple. Just - compile all of the source files (*.c) and link them into - a library. You need to keep "expreval.h" for the header file.

-

You may have to make some changes to the library. I've - tried to make doing so as simple as possible. If you - need to change the include files or some macros or whatnot, - edit the file "exprincl.h" This file includes any other files - needed. You should not have to change to much. I have - tried to stick as close to ANSI/ISO C as I can.

-
- -
-

Drawbacks/Problems

-

The following is a list of some basic drawbacks of this - library: -

-

-
- -
-

Problems and Solutions

- -
- -
-

Example Use with Fast Variable Access

- -

This is an example application of this library. It is a - graphics program that calculates the color value of a - pixel based on it's X,Y co-ordinate. It uses a made-up - image library called graphic-lib. It uses faster variable - access by using the exprValListGetAddress function.

-

Note that this codes has not actually been tested. See the - test applications (test and imagegen) for other examples.

- -
- 
-/* Include files */
-#include <stdio.h>
-#include <stdlib.h>
-#include <setjmp.h>
-#include "graphiclib.h"
-#include "expreval.h"
-
-char *transerr(int err)
-    {
-    /* Translate error code into message */
-    }
-
-void gen_image(char *name, int w, int h, char *expr);
-    {
-    exprFuncList *f = NULL;
-    exprValList *v = NULL;
-    exprValList *c = NULL;
-    exprObj *o = NULL;
-    int x, y, err;
-    jmp_buf jumper;
-    int image;
-    EXPRTYPE *v_x, *v_y;
-    EXPRTYPE *v_r, *v_g, *v_b;
-    EXPRTYPE global_value;
-
-    /* Error handling */
-    err = setjmp(jumper);
-    if(err)
-        {
-        if(err != ID_IMAGENOERROR)
-            printf("Error %d occurred: %s\n", err, transerr(err));
-
-        exprFree(o);
-        exprFreeFuncList(f);
-        exprFreeValList(v);
-        exprFreeValList(c);
-
-        image_free(image);
-        return;
-        }
-
-    /* Set up lists */
-
-    /* Function list */
-    err = exprFuncListCreate(&f);
-    if(err != EXPR_ERROR_NOERROR)
-        longjmp(jumper, err);
-
-    err = exprFuncListInit(f);
-    if(err != EXPR_ERROR_NOERROR)
-        {
-        printf("Function list init error. Functions may not be available.\n");
-        }
-
-    /* Variable list */
-    err = exprValListCreate(&v);
-    if(err != EXPR_ERROR_NOERROR)
-        longjmp(jumper, err);
-
-    /* Constant list */
-    err = exprValListCreate(&c);
-    if(err != EXPR_ERROR_NOERROR)
-        {
-        printf("Constants not available\n");
-        }
-    else
-        {
-        err = exprValListInit(c);
-        if(err != EXPR_ERROR_NOERROR)
-            printf("Constant list init error. Constants may not be available.\n");
-        }
-
-    /* Create and parse the expression */
-
-    /* Create */
-    err = exprCreate(&o, f, v, c, NULL, 0);
-    if(err != EXPR_ERROR_NOERROR)
-        longjmp(jumper, err);
-
-    /* Parse expression */
-    err = exprParse(o, expr);
-    if(err != EXPR_ERROR_NOERROR)
-        longjmp(jumper, err);
-
-
-    /* Create the image */
-    image = image_create(w, h);
-    if(image == 0)
-        {
-        longjmp(jumper, ID_IMAGECREATEERROR);
-        }
-
-    /* Add width and height to variable list */
-    exprValListAdd(v, "w", (EXPRTYPE)w);
-    exprValListAdd(v, "h", (EXPRTYPE)h);
-
-    /* Add x and y to the list */
-    exprValListAdd(v, "x", 0.0);
-    exprValListAdd(v, "y", 0.0);
-
-    /* Add r, g, and b to the list */
-    exprValListAdd(v, "r", 0.0);
-    exprValListAdd(v, "g", 0.0);
-    exprValListAdd(b, "b", 0.0);
-
-    /* Get addresses.  Assume no error */
-    exprValListGetAddress(v, "x", &v_x);
-    exprValListGetAddress(v, "y", &v_y);
-
-    exprValListGetAddress(v, "r", &v_r);
-    exprValListGetAddress(v, "g", &v_g);
-    exprValListGetAddress(v, "g", &v_b);
-    
-    /* A way to add global variables that can be used by two different lists. */
-    exprValListAddAddress(v, "global", &global_value);
-    /* exprValListAddAddress(v2, "global", &global_value); */
-    
-    /* Also, exprValListAddAddress can be used to add variables directly.
-       Instead of:
-       
-       EXPRTYPE *a;
-       
-       exprValListAdd(v, "a", 0.0);
-       exprValListGetAddresss(v, "a", &a);
-       
-       You can do:
-       
-       EXPRTYPE a;
-       
-       exprValListAddAddresss(v, "a", &a);
-       
-       If you do this, you must ensure that the stack variable exists as long
-       as it is used by expression, otherwise it may cause a memory access
-       violation. */
-    
-
-    for(y = 0; y < h; y++)
-        {
-        for(x = 0; x < w; x++)
-            {
-            /* Directly set the x and y variables */
-            *v_x = (EXPRTYPE)x;
-            *v_y = (EXPRTYPE)y;
-
-            /* Eval expression, ignoring errors */
-            exprEval(o);
-
-            /* Set pixel, using variables directly */
-            image_setpixel(image, x, y, (int)(*v_r), (int)(*v_g), (int)(*v_b));
-            }
-        }
-
-    /* Save image */
-    image_save(image, name);
-
-    /* Done */
-    longjmp(jumper, ID_IMAGENOERROR);
-    }
-
-void main(void)
-    {
-    char name[MAXPATH]
-    char tmp[10];
-    char expr[4096];
-    int sx, sy;
-
-    printf("Image name to save: ");
-    gets(name);
-
-    printf("Image width: ");
-    gets(tmp);
-    sx = atoi(tmp);
-
-    printf("Image height: ");
-    gets(tmp);
-    sy = atoi(tmp);
-
-    printf("Color Expression (Use x, y, w, h Set r, g, b): ");
-    gets(expr);
-
-    gen_image(name, sx, sy, expr);
-    }
-
-
-
-
- - - + + +ExprEval Library + + + + +
+

ExprEval Library

+
+
+ +
+

Contents

+

+ +

+
+ +
+

Introduction

+
+

ExprEval Help document. This document is probably full of + bugs and mispellings. I may get around to proofreading + it later.

+

ExprEval is a C based expression evaluation library. + It is entirely C based, but can be used in C++ programs + as well.. The source code is provided for the library + so that it can be recompiled for the specific system + or compiler.

+

ExprEval makes adding mathematical expression support to + an application easy. It takes an expression string and + parses it, and then it can evaluate it over and over. + This library also has support for functions, constants, + and variables. All of these items are stored in + seperate lists so they can be shared among expressions or + they can be private to a single expression or any mix and + match. It is up to the developer how to link them together. + You can also create your own custom functions.

+
+
+ +
+

License

+
+

This library is licensed under the + ExprEval License. +

+
+
+ +
+

Expression Syntax

+
+

Expressions have pretty much the same syntax as they + would have on paper, with the following exceptions: +

+

+

More than one expression may be contained within an expression string. + As shown above, each expression must end with a semicolon, even if + only one expression is in the string. The value of an expression + string is the value of the last expression in the string.
+ Examlples: +

+

+

Some functions may take reference parameters. These parameters are + references to other variables. You can mix reference parameters + with normal parameters. The order of the normal parameters must + remain the same and the order of the reference parameters must + remain the same.
+ Examples: +

+

+

Expressions may also be nested with parenthesis.
+ Examples: +

+

+

Expressions may also have whitespace characters and comments. + Whitespace characters such as newlines, linefeeds, carriage + returns, spaces, and tabs are ignored. Comments begin with + the pound sign '#' and end at the end of the line.
+ Example: +

+

+

If a variable is used in an expression, but that variable does not exist, + it is considered zero. If it does exist then its value is used instead. +

+
+
+ +
+

Using ExprEval in an Application

+
+

Using ExprEval in an application can be a little difficult. + You generally follow these steps: +

+ You can manipulate the lists in any order after their creation. + However, functions are translated during the parse, so after + parsing an expression, manipulating the function list will make + no change to an expression. Variables and constants can be + manipulated after a parse to change the result of an expression. + However, you must add any constants to be used by an expression + to the constant list BEFORE parsing the expression, + otherwise it will be seen as a variable. Applications can change + both variables and constants, however the expression can only + change variables. Expressions may NOT assign to a constant + and expressions may NOT use constants as a reference parameter.

+

Function, variable, and constant list example: +

+

+

Expression object example: +

+

+

Expression parse example: +

+

+

Expression evaluation example: +

+

+

Free the expression object and lists example: +

+

+
+
+ +
+

Fast Variable Access

+
+

A new feature in ExprEval is fast variable access. This + is simply a technique of quickly accessing variables + by directly accessing their memory locations instead + of using the value list functions. Fast variable access + is always used internally in ExprEval. You must + NOT clear a variable list until after all expressions + using it are completely finished evaluating. Then you + must reparse the expressions before using them again. + The reason is simple. When fast variable access is used, + the variable memory location is directly accessed If you + clear a variable list and then evaluate an expression, + it will access invalid memory.

+

You can also use fast variable access in you application + to dramatically speed up loops. This is accomplished as + follows: +

+

+
+
+ +
+

Using the Internal Functions and Constants

+
+

To use the internal functions, they must first be initialized + into a function list with exprFuncListInit. To use the + internal constants, they must first be initialized into a + value list with exprValListInit. For a list of the + internal functions and constants, see the application + help template file: ExprTmpl.html + You may use this file in your own applications so you don't + have to write a detail on the functions in ExprEval. All + you have to do is add you own functions and constants to + the file if there are any. +

+
+ +
+

Creating Custom Functions

+
+

Custom functions can be created for use by the library. + This is how a function should look +

+ + obj is a pointer to the expression object that called + the function, nodes is a pointer to an array of nodes + that are the parameters of this function, nodecount is + the number of items in the array (the number of parameters), + refs is an array of pointers to referenced variables, + refcount is the number of referenced variables, + and val is a pointer to a variable to recieve the result + of the function. The function should return an error value + indicating the error status of the function. +

+

Solving a function typically goes as follows: +

+

+

Example: +

+

+

In order to use a custom function, it must be added to + a function list before the expression is parsed by using + exprFuncListAdd

+
+
+ +
+

Reference

+
+

Headers: +

+

+

Defines: +

+

+

Objects: +

+

+

Types: +

+

+

Version information functions: +

+

+

Function list functions: +

+

+

Value list functions: +

+

+

Expression functions: +

+

+

Some useful functions +

+

+
+
+ +
+

Compiling the ExprEval library

+

Compiling the ExprEval library is pretty simple. Just + compile all of the source files (*.c) and link them into + a library. You need to keep "expreval.h" for the header file.

+

You may have to make some changes to the library. I've + tried to make doing so as simple as possible. If you + need to change the include files or some macros or whatnot, + edit the file "exprincl.h" This file includes any other files + needed. You should not have to change to much. I have + tried to stick as close to ANSI/ISO C as I can.

+
+ +
+

Drawbacks/Problems

+

The following is a list of some basic drawbacks of this + library: +

+

+
+ +
+

Problems and Solutions

+ +
+ +
+

Example Use with Fast Variable Access

+ +

This is an example application of this library. It is a + graphics program that calculates the color value of a + pixel based on it's X,Y co-ordinate. It uses a made-up + image library called graphic-lib. It uses faster variable + access by using the exprValListGetAddress function.

+

Note that this codes has not actually been tested. See the + test applications (test and imagegen) for other examples.

+ +
+ 
+/* Include files */
+#include <stdio.h>
+#include <stdlib.h>
+#include <setjmp.h>
+#include "graphiclib.h"
+#include "expreval.h"
+
+char *transerr(int err)
+    {
+    /* Translate error code into message */
+    }
+
+void gen_image(char *name, int w, int h, char *expr);
+    {
+    exprFuncList *f = NULL;
+    exprValList *v = NULL;
+    exprValList *c = NULL;
+    exprObj *o = NULL;
+    int x, y, err;
+    jmp_buf jumper;
+    int image;
+    EXPRTYPE *v_x, *v_y;
+    EXPRTYPE *v_r, *v_g, *v_b;
+    EXPRTYPE global_value;
+
+    /* Error handling */
+    err = setjmp(jumper);
+    if(err)
+        {
+        if(err != ID_IMAGENOERROR)
+            printf("Error %d occurred: %s\n", err, transerr(err));
+
+        exprFree(o);
+        exprFreeFuncList(f);
+        exprFreeValList(v);
+        exprFreeValList(c);
+
+        image_free(image);
+        return;
+        }
+
+    /* Set up lists */
+
+    /* Function list */
+    err = exprFuncListCreate(&f);
+    if(err != EXPR_ERROR_NOERROR)
+        longjmp(jumper, err);
+
+    err = exprFuncListInit(f);
+    if(err != EXPR_ERROR_NOERROR)
+        {
+        printf("Function list init error. Functions may not be available.\n");
+        }
+
+    /* Variable list */
+    err = exprValListCreate(&v);
+    if(err != EXPR_ERROR_NOERROR)
+        longjmp(jumper, err);
+
+    /* Constant list */
+    err = exprValListCreate(&c);
+    if(err != EXPR_ERROR_NOERROR)
+        {
+        printf("Constants not available\n");
+        }
+    else
+        {
+        err = exprValListInit(c);
+        if(err != EXPR_ERROR_NOERROR)
+            printf("Constant list init error. Constants may not be available.\n");
+        }
+
+    /* Create and parse the expression */
+
+    /* Create */
+    err = exprCreate(&o, f, v, c, NULL, 0);
+    if(err != EXPR_ERROR_NOERROR)
+        longjmp(jumper, err);
+
+    /* Parse expression */
+    err = exprParse(o, expr);
+    if(err != EXPR_ERROR_NOERROR)
+        longjmp(jumper, err);
+
+
+    /* Create the image */
+    image = image_create(w, h);
+    if(image == 0)
+        {
+        longjmp(jumper, ID_IMAGECREATEERROR);
+        }
+
+    /* Add width and height to variable list */
+    exprValListAdd(v, "w", (EXPRTYPE)w);
+    exprValListAdd(v, "h", (EXPRTYPE)h);
+
+    /* Add x and y to the list */
+    exprValListAdd(v, "x", 0.0);
+    exprValListAdd(v, "y", 0.0);
+
+    /* Add r, g, and b to the list */
+    exprValListAdd(v, "r", 0.0);
+    exprValListAdd(v, "g", 0.0);
+    exprValListAdd(b, "b", 0.0);
+
+    /* Get addresses.  Assume no error */
+    exprValListGetAddress(v, "x", &v_x);
+    exprValListGetAddress(v, "y", &v_y);
+
+    exprValListGetAddress(v, "r", &v_r);
+    exprValListGetAddress(v, "g", &v_g);
+    exprValListGetAddress(v, "g", &v_b);
+    
+    /* A way to add global variables that can be used by two different lists. */
+    exprValListAddAddress(v, "global", &global_value);
+    /* exprValListAddAddress(v2, "global", &global_value); */
+    
+    /* Also, exprValListAddAddress can be used to add variables directly.
+       Instead of:
+       
+       EXPRTYPE *a;
+       
+       exprValListAdd(v, "a", 0.0);
+       exprValListGetAddresss(v, "a", &a);
+       
+       You can do:
+       
+       EXPRTYPE a;
+       
+       exprValListAddAddresss(v, "a", &a);
+       
+       If you do this, you must ensure that the stack variable exists as long
+       as it is used by expression, otherwise it may cause a memory access
+       violation. */
+    
+
+    for(y = 0; y < h; y++)
+        {
+        for(x = 0; x < w; x++)
+            {
+            /* Directly set the x and y variables */
+            *v_x = (EXPRTYPE)x;
+            *v_y = (EXPRTYPE)y;
+
+            /* Eval expression, ignoring errors */
+            exprEval(o);
+
+            /* Set pixel, using variables directly */
+            image_setpixel(image, x, y, (int)(*v_r), (int)(*v_g), (int)(*v_b));
+            }
+        }
+
+    /* Save image */
+    image_save(image, name);
+
+    /* Done */
+    longjmp(jumper, ID_IMAGENOERROR);
+    }
+
+void main(void)
+    {
+    char name[MAXPATH]
+    char tmp[10];
+    char expr[4096];
+    int sx, sy;
+
+    printf("Image name to save: ");
+    gets(name);
+
+    printf("Image width: ");
+    gets(tmp);
+    sx = atoi(tmp);
+
+    printf("Image height: ");
+    gets(tmp);
+    sy = atoi(tmp);
+
+    printf("Color Expression (Use x, y, w, h Set r, g, b): ");
+    gets(expr);
+
+    gen_image(name, sx, sy, expr);
+    }
+
+
+
+
+ + + diff --git a/src/mod/applications/mod_expr/exprtmpl.html b/src/mod/applications/mod_expr/exprtmpl.html index f4f6187c3c..6781baece0 100644 --- a/src/mod/applications/mod_expr/exprtmpl.html +++ b/src/mod/applications/mod_expr/exprtmpl.html @@ -1,828 +1,828 @@ - - - -Expression Help - - - - - -
-

Expression Help

-
-
- -
-

Contents

-

- -

-
- -
-

Expression Syntax

-
-

Expressions have pretty much the same syntax as they - would have on paper, with the following exceptions: -

-

-

More than one expression may be contained within an expression string. - As shown above, each expression must end with a semicolon, even if - only one expression is in the string. The value of an expression - string is the value of the last expression in the string.
- Examlples: -

-

-

Some functions may take reference parameters. These parameters are - references to other variables. You can mix reference parameters - with normal parameters. The order of the normal parameters must - remain the same and the order of the reference parameters must - remain the same.
- Examples: -

-

-

Expressions may also be nested with parenthesis.
- Examples: -

-

-

Expressions may also have whitespace characters and comments. - Whitespace characters such as newlines, linefeeds, carriage - returns, spaces, and tabs are ignored. Comments begin with - the pound sign '#' and end at the end of the line.
- Example: -

-

-

If a variable is used in an expression, but that variable does not exist, - it is considered zero. If it does exist then its value is used instead. -

-

Notice: An expression can NOT assign to a constant and an - expression can NOT use a constant as a reference parameter. -

-
-
- -
-

Order of operators.

-
-

The order of operators are processed correctly in ExprEval. - The parameters to functions may be evaluated out of order, depending - on the function itself.

- - The following illustrates the order of operators: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
OperatorDirectionExample
Functions and ParenthesisN/A(x + 5) * sin(d);
NegationRight to Lefty = -2;
ExponentsLeft to Righty = x ^ 2;
Multiplication and DivisionLeft to Rightx * 5 / y;
Addition and SubtractionLeft to Right4 + 5 - 3;
AssignmentRight to Leftx = y = z = 0;
- -
-
- -
-

ExprEval Internal Functions

-
- The following functions are provided with ExprEval: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
FunctionMin. ArgsMax. ArgsMin. Ref ArgsMax. Ref ArgsResult/Comment
abs(v)1100Absolute value of v.
- abs(-4.3) returns 4.3
mod(v,d)2200Remainder of v/d.
- mod(5.2,2.5) return 0.2
ipart(v)1100The integer part of v.
- ipart(3.2) returns 3
fpart(v)1100The fractional part of v.
- fpart(3.2) returns 0.2
min(v,...)1None00The minimum number passed.
- min(3,2,-5,-2,7) returns -5
max(v,...)1None00The maximum number passed.
- max(3,2,-5,-2,7) returns 7
pow(a,b)2200The value a raised to the power b.
- pow(3.2,1.7) returns 3.21.7
sqrt(a)1100The square root of a.
- sqrt(16) returns 4
sin(a)1100The sine of a radians.
- sin(1.5) returns around 0.997
sinh(a)1100The hyperbolic sine of a.
- sinh(1.5) returns around 2.129
asin(a)1100The arc-sine of a in radians.
- asin(0.5) returns around 0.524
cos(a)1100The cosine of a radians.
- cos(1.5) returns around 0.0707
cosh(a)1100The hyperbolic cosine of a.
- cosh(1.5) returns around 2.352
acos(a)1100The arc-cosine of a in radians.
- acos(0.5) returns around 1.047
tan(a)1100The tangent of a radians.
- tan(1.5) returns around 14.101
tanh(a)1100The hyperbolic tangent of a.
- tanh(1.5) returns around 0.905
atan(a)1100The arc-tangent of a in radians.
- atan(0.3) returns about 0.291
atan2(y,x)2200The arc-tangent of y/x, with quadrant correction.
- atan2(4,3) returns about 0.927
log(a)1100The base 10 logarithm of a.
- log(100) returns 2
pow10(a)110010 raised to the power of a.
- pow10(2) returns 100
ln(a)1100The base e logarithm of a.
- ln(2.8) returns around 1.030
exp(a)1100e raised to the power of a.
- exp(2) returns around 7.389
logn(a,b)2200The base b logarithm of a.
- logn(16,2) returns 4
ceil(a)1100Rounds a up to the nearest integer.
- ceil(3.2) returns 4
floor(a)1100Rounds a down to the nearest integer.
- floor(3.2) returns 3
rand(&seed)0011Returns a number between 0 up to but not including 1.
random(a,b,&seed)2211Returns a number between a up to and including b.
randomize(&seed)0011Seed the random number generator with a value - based on the current time.
- Return value is unknown
deg(a)1100Returns a radians converted to degrees.
- deg(3.14) returns around 179.909
rad(a)1100Returns a degrees converted to radians.
- rad(180) returns around 3.142
recttopolr(x,y)2200Returns the polar radius of the rectangular co-ordinates.
- recttopolr(2,3) returns around 3.606
recttopola(x,y)2200Returns the polar angle (0...2PI) in radians of the rectangular co-ordinates.
- recttopola(2,3) returns around 0.588
poltorectx(r,a)2200Returns the x rectangular co-ordinate of the polar - co-ordinates.
- poltorectx(3,1.5) returns around 0.212
poltorecty(r,a)2200Returns the y rectangular co-ordinate of the polar - co-ordinates.
- poltorecty(3,1.5) returns around 2.992
if(c,t,f)3300Evaluates and returns t if c is not 0.0. - Else evaluates and returns f.
- if(0.1,2.1,3.9) returns 2.1
select(c,n,z[,p])3400Returns n if c is less than 0.0. Returns z - if c is 0.0. If c is greater than 0.0 and only - three arguments were passed, returns z. If c - is greater than 0.0 and four arguments were passed, - return p.
- select(3,1,4,5) returns 5
equal(a,b)2200Returns 1.0 if a is equal to b. Else returns 0.0
- equal(3,2) returns 0.0
above(a,b)2200Returns 1.0 if a is above b. Else returns 0.0
- above(3,2) returns 1.0
below(a,b)2200Returns 1.0 if a is below b. Else returns 0.0
- below(3,2) returns 0.0
avg(a,...)1None00Returns the average of the values passed.
- avg(3,3,6) returns 4
clip(v,min,max)3300Clips v to the range from min to max. If v is less - than min, it returns min. If v is greater than - max it returns max. Otherwise it returns v.
- clip(3,1,2) returns 2
clamp(v,min,max)3300Clamps v to the range from min to max, looping - if needed.
- clamp(8.2,1.3,4.7) returns 1.4
pntchange(side1old, side2old, side1new, side2new, oldpnt)5500This is used to translate points from different - scale. It works no matter the orientation as long - as the sides are lined up correctly.
- pntchange(-1,1,0,480,-0.5) returns 120 (x example)
- pntchange(-1,1,480,0,-0.5) returns 360 (y example)
poly(x,c1,...)2None00This function calculates the polynomial. x is the value - to use in the polynomial. c1 and on are the coefficients.
- poly(4,6,9,3,1,4) returns 2168
- same as 6*44 + 9*43 + 3*42 + 1*41 + 4*40
and(a,b)2200Returns 0.0 if either a or b are 0.0 Else returns 1.0
- and(2.1,0.0) returns 0.0
or(a,b)2200Returns 0.0 if both a and b are 0.0 Else returns 1.0
- or(2.1,0.0) returns 1.0
not(a)1100Returns 1.0 if a is 0.0 Else returns 0.0
- not(0.3) returns 0.0
for(init,test,inc,a1,...)4None00This function acts like a for loop in C. First init is - evaluated. Then test is evaluated. As long as the - test is not 0.0, the action statements (a1 to an) are - evaluated, the inc statement is evaluated, and the test - is evaluated again. The result is the result of the - final action statement.
- for(x=0,below(x,11),x=x+1,y=y+x) returns 55.0 (if y was - initially 0.0)
many(expr,...)1None00This function treats many subexpressions as a single object - (function). It is mainly for the 'for' function.
- for(many(j=5,k=1),above(j*k,0.001),many(j=j+5,k=k/2),0)
- -
-
- -
-

ExprEval Internal Constants

-
- The following constants are provided with ExprEval: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
ConstantMath FormValue
M_Ee2.7182818284590452354
M_LOG2Elog2(e)1.4426950408889634074
M_LOG10Elog10(e)0.43429448190325182765
M_LN2ln(2)0.69314718055994530942
M_LN10ln(10)2.30258509299404568402
M_PIπ3.14159265358979323846
M_PI_2π/21.57079632679489661923
M_PI_4π/40.78539816339744830962
M_1_PI1/π0.31830988618379067154
M_2_PI2/π0.63661977236758134308
M_1_SQRTPI1/√(π)0.56418958354776
M_2_SQRTPI2/√(π)1.12837916709551257390
M_SQRT2√(2)1.41421356237309504880
M_1_SQRT21/√(2)0.70710678118654752440
-
-
- -
-

Application Internal Functions

-
- Application defined expression functions go here. - - - - - - - - - - - - - - - - - -
FunctionMin. ArgsMax. ArgsMin. Ref ArgsMax. Ref ArgsResult/Comment
-
-
- -
-

Application Internal Constants

-
- Application defined expression constants go here. - - - - - - - - - - - -
ConstantMath FormValue
-
-
- -
-

Application Internal Variables

-
- Application defined expression variables go here. - - - - - - - - - - - -
VariableMath FormValue
-
-
- - - - - - + + + +Expression Help + + + + + +
+

Expression Help

+
+
+ +
+

Contents

+

+ +

+
+ +
+

Expression Syntax

+
+

Expressions have pretty much the same syntax as they + would have on paper, with the following exceptions: +

+

+

More than one expression may be contained within an expression string. + As shown above, each expression must end with a semicolon, even if + only one expression is in the string. The value of an expression + string is the value of the last expression in the string.
+ Examlples: +

+

+

Some functions may take reference parameters. These parameters are + references to other variables. You can mix reference parameters + with normal parameters. The order of the normal parameters must + remain the same and the order of the reference parameters must + remain the same.
+ Examples: +

+

+

Expressions may also be nested with parenthesis.
+ Examples: +

+

+

Expressions may also have whitespace characters and comments. + Whitespace characters such as newlines, linefeeds, carriage + returns, spaces, and tabs are ignored. Comments begin with + the pound sign '#' and end at the end of the line.
+ Example: +

+

+

If a variable is used in an expression, but that variable does not exist, + it is considered zero. If it does exist then its value is used instead. +

+

Notice: An expression can NOT assign to a constant and an + expression can NOT use a constant as a reference parameter. +

+
+
+ +
+

Order of operators.

+
+

The order of operators are processed correctly in ExprEval. + The parameters to functions may be evaluated out of order, depending + on the function itself.

+ + The following illustrates the order of operators: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
OperatorDirectionExample
Functions and ParenthesisN/A(x + 5) * sin(d);
NegationRight to Lefty = -2;
ExponentsLeft to Righty = x ^ 2;
Multiplication and DivisionLeft to Rightx * 5 / y;
Addition and SubtractionLeft to Right4 + 5 - 3;
AssignmentRight to Leftx = y = z = 0;
+ +
+
+ +
+

ExprEval Internal Functions

+
+ The following functions are provided with ExprEval: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FunctionMin. ArgsMax. ArgsMin. Ref ArgsMax. Ref ArgsResult/Comment
abs(v)1100Absolute value of v.
+ abs(-4.3) returns 4.3
mod(v,d)2200Remainder of v/d.
+ mod(5.2,2.5) return 0.2
ipart(v)1100The integer part of v.
+ ipart(3.2) returns 3
fpart(v)1100The fractional part of v.
+ fpart(3.2) returns 0.2
min(v,...)1None00The minimum number passed.
+ min(3,2,-5,-2,7) returns -5
max(v,...)1None00The maximum number passed.
+ max(3,2,-5,-2,7) returns 7
pow(a,b)2200The value a raised to the power b.
+ pow(3.2,1.7) returns 3.21.7
sqrt(a)1100The square root of a.
+ sqrt(16) returns 4
sin(a)1100The sine of a radians.
+ sin(1.5) returns around 0.997
sinh(a)1100The hyperbolic sine of a.
+ sinh(1.5) returns around 2.129
asin(a)1100The arc-sine of a in radians.
+ asin(0.5) returns around 0.524
cos(a)1100The cosine of a radians.
+ cos(1.5) returns around 0.0707
cosh(a)1100The hyperbolic cosine of a.
+ cosh(1.5) returns around 2.352
acos(a)1100The arc-cosine of a in radians.
+ acos(0.5) returns around 1.047
tan(a)1100The tangent of a radians.
+ tan(1.5) returns around 14.101
tanh(a)1100The hyperbolic tangent of a.
+ tanh(1.5) returns around 0.905
atan(a)1100The arc-tangent of a in radians.
+ atan(0.3) returns about 0.291
atan2(y,x)2200The arc-tangent of y/x, with quadrant correction.
+ atan2(4,3) returns about 0.927
log(a)1100The base 10 logarithm of a.
+ log(100) returns 2
pow10(a)110010 raised to the power of a.
+ pow10(2) returns 100
ln(a)1100The base e logarithm of a.
+ ln(2.8) returns around 1.030
exp(a)1100e raised to the power of a.
+ exp(2) returns around 7.389
logn(a,b)2200The base b logarithm of a.
+ logn(16,2) returns 4
ceil(a)1100Rounds a up to the nearest integer.
+ ceil(3.2) returns 4
floor(a)1100Rounds a down to the nearest integer.
+ floor(3.2) returns 3
rand(&seed)0011Returns a number between 0 up to but not including 1.
random(a,b,&seed)2211Returns a number between a up to and including b.
randomize(&seed)0011Seed the random number generator with a value + based on the current time.
+ Return value is unknown
deg(a)1100Returns a radians converted to degrees.
+ deg(3.14) returns around 179.909
rad(a)1100Returns a degrees converted to radians.
+ rad(180) returns around 3.142
recttopolr(x,y)2200Returns the polar radius of the rectangular co-ordinates.
+ recttopolr(2,3) returns around 3.606
recttopola(x,y)2200Returns the polar angle (0...2PI) in radians of the rectangular co-ordinates.
+ recttopola(2,3) returns around 0.588
poltorectx(r,a)2200Returns the x rectangular co-ordinate of the polar + co-ordinates.
+ poltorectx(3,1.5) returns around 0.212
poltorecty(r,a)2200Returns the y rectangular co-ordinate of the polar + co-ordinates.
+ poltorecty(3,1.5) returns around 2.992
if(c,t,f)3300Evaluates and returns t if c is not 0.0. + Else evaluates and returns f.
+ if(0.1,2.1,3.9) returns 2.1
select(c,n,z[,p])3400Returns n if c is less than 0.0. Returns z + if c is 0.0. If c is greater than 0.0 and only + three arguments were passed, returns z. If c + is greater than 0.0 and four arguments were passed, + return p.
+ select(3,1,4,5) returns 5
equal(a,b)2200Returns 1.0 if a is equal to b. Else returns 0.0
+ equal(3,2) returns 0.0
above(a,b)2200Returns 1.0 if a is above b. Else returns 0.0
+ above(3,2) returns 1.0
below(a,b)2200Returns 1.0 if a is below b. Else returns 0.0
+ below(3,2) returns 0.0
avg(a,...)1None00Returns the average of the values passed.
+ avg(3,3,6) returns 4
clip(v,min,max)3300Clips v to the range from min to max. If v is less + than min, it returns min. If v is greater than + max it returns max. Otherwise it returns v.
+ clip(3,1,2) returns 2
clamp(v,min,max)3300Clamps v to the range from min to max, looping + if needed.
+ clamp(8.2,1.3,4.7) returns 1.4
pntchange(side1old, side2old, side1new, side2new, oldpnt)5500This is used to translate points from different + scale. It works no matter the orientation as long + as the sides are lined up correctly.
+ pntchange(-1,1,0,480,-0.5) returns 120 (x example)
+ pntchange(-1,1,480,0,-0.5) returns 360 (y example)
poly(x,c1,...)2None00This function calculates the polynomial. x is the value + to use in the polynomial. c1 and on are the coefficients.
+ poly(4,6,9,3,1,4) returns 2168
+ same as 6*44 + 9*43 + 3*42 + 1*41 + 4*40
and(a,b)2200Returns 0.0 if either a or b are 0.0 Else returns 1.0
+ and(2.1,0.0) returns 0.0
or(a,b)2200Returns 0.0 if both a and b are 0.0 Else returns 1.0
+ or(2.1,0.0) returns 1.0
not(a)1100Returns 1.0 if a is 0.0 Else returns 0.0
+ not(0.3) returns 0.0
for(init,test,inc,a1,...)4None00This function acts like a for loop in C. First init is + evaluated. Then test is evaluated. As long as the + test is not 0.0, the action statements (a1 to an) are + evaluated, the inc statement is evaluated, and the test + is evaluated again. The result is the result of the + final action statement.
+ for(x=0,below(x,11),x=x+1,y=y+x) returns 55.0 (if y was + initially 0.0)
many(expr,...)1None00This function treats many subexpressions as a single object + (function). It is mainly for the 'for' function.
+ for(many(j=5,k=1),above(j*k,0.001),many(j=j+5,k=k/2),0)
+ +
+
+ +
+

ExprEval Internal Constants

+
+ The following constants are provided with ExprEval: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
ConstantMath FormValue
M_Ee2.7182818284590452354
M_LOG2Elog2(e)1.4426950408889634074
M_LOG10Elog10(e)0.43429448190325182765
M_LN2ln(2)0.69314718055994530942
M_LN10ln(10)2.30258509299404568402
M_PIπ3.14159265358979323846
M_PI_2π/21.57079632679489661923
M_PI_4π/40.78539816339744830962
M_1_PI1/π0.31830988618379067154
M_2_PI2/π0.63661977236758134308
M_1_SQRTPI1/√(π)0.56418958354776
M_2_SQRTPI2/√(π)1.12837916709551257390
M_SQRT2√(2)1.41421356237309504880
M_1_SQRT21/√(2)0.70710678118654752440
+
+
+ +
+

Application Internal Functions

+
+ Application defined expression functions go here. + + + + + + + + + + + + + + + + + +
FunctionMin. ArgsMax. ArgsMin. Ref ArgsMax. Ref ArgsResult/Comment
+
+
+ +
+

Application Internal Constants

+
+ Application defined expression constants go here. + + + + + + + + + + + +
ConstantMath FormValue
+
+
+ +
+

Application Internal Variables

+
+ Application defined expression variables go here. + + + + + + + + + + + +
VariableMath FormValue
+
+
+ + + + + +