/*
* Copyright (C) 1999, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2011,
* 2012, 2013 Free Software Foundation, Inc.
*
* This file is part of GNU libmatheval
*
* GNU libmatheval is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* GNU libmatheval is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU libmatheval. If not, see
* .
*/
#ifndef MATHEVAL_H
#define MATHEVAL_H 1
#ifdef __cplusplus
extern "C" {
#endif
/* Create evaluator from string representing function. Function
* returns pointer that should be passed as first argument to all
* other library functions. If an error occurs, function will
* return null pointer. */
extern void *evaluator_create(char *string);
/* Destroy evaluator specified. */
extern void evaluator_destroy(void *evaluator);
/* Evaluate function represented by evaluator given. Variable
* names and respective values are represented by function third
* and fourth argument. Number of variables i.e. length of these
* two arrays is given by second argument. Function returns
* evaluated function value. In case that function contains
* variables with names not given through third function argument,
* value of this variable is undeterminated. */
extern double evaluator_evaluate(void *evaluator, int count,
char **names, double *values);
/* Return textual representation of function given by evaluator.
* Textual representation is built after evaluator simplification,
* so it may differ from original string supplied when creating
* evaluator. String representing function is allocated,
* remembered and later destroyed by evaluator object, thus caller
* must not free returned pointer. Returned information is valid
* until evaluator object destroyed. */
extern char *evaluator_get_string(void *evaluator);
/* Get array of strings with names of variables appearing in
* function represented by given evaluator. Only variables
* referenced by evaluator after simplification are returned.
* Address of first string in array is stored into location
* pointed by function second argument. Number of array elements
* is stored into location pointed by third argument. Array is
* allocated, remembered and later destroyed by evaluator object,
* thus caller must not free any of string nor array itself.
* Returned information is valid until evaluator object destroyed.
*/
extern void evaluator_get_variables(void *evaluator,
char ***names, int *count);
/* Create evaluator for first derivative of function represented
* by evaluator given as first argument using derivative variable
* given as second argument. */
extern void *evaluator_derivative(void *evaluator, char *name);
/* Helper functions to simplify evaluation when variable names are
* "x", "x" and "y" or "x" and "y" and "z" respectively. */
extern double evaluator_evaluate_x(void *evaluator, double x);
extern double evaluator_evaluate_x_y(void *evaluator, double x,
double y);
extern double evaluator_evaluate_x_y_z(void *evaluator, double x,
double y, double z);
/* Helper functions to simplify differentiation when variable
* names are "x" or "y" or "z" respectively. */
extern void *evaluator_derivative_x(void *evaluator);
extern void *evaluator_derivative_y(void *evaluator);
extern void *evaluator_derivative_z(void *evaluator);
#ifdef __cplusplus
}
#endif
#endif