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C++ Mathematical Expression Library (ExprTk) http://www.partow.net/programming/exprtk/index.html

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Arash Partow
2013-04-01 20:30:28 +11:00
parent 7fdaf28b12
commit 6b0b02a805
2 changed files with 35 additions and 12 deletions
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6
exprtk_test.cpp
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@ -3234,7 +3234,11 @@ inline bool run_test18()
"equal(va_func(x+t,y+v,z+u,w+w,u+z,v+y,t+x),2*(x+y+z+w+u+v+t))",
"equal(1+va_func(1,x,3,y,5,z,7,w,9),(1+x+3+y+5+z+7+w+9)+1)",
"equal(va_func(va_func(x,y,z,w,u,v,t),va_func(x,y,z,w,u,v,t)),2*(x+y+z+w+u+v+t))",
"equal(va_func(va_func(x),va_func(y),va_func(z)),va_func(x,y,z))"
"equal(va_func(va_func(x),va_func(y),va_func(z)),va_func(x,y,z))",
"equal(va_func(va_func(va_func(va_func(va_func(va_func(va_func(va_func(x)))))))),x)",
"equal(va_func(va_func(va_func(va_func(va_func(va_func(va_func(va_func(123.456)))))))),123.456)",
"equal(va_func(va_func(va_func(va_func(va_func(va_func(va_func(va_func(x+1)))))))),x+1)",
"equal(va_func(va_func(va_func(va_func(va_func(va_func(va_func(va_func(x+y)))))))),x+y)"
};
static const std::size_t expr_str_list_size = sizeof(expr_str_list) / sizeof(std::string);

41
readme.txt
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@ -407,35 +407,40 @@ correctly optimize such expressions for a given architecture.
(05) Expression lengths are limited only by storage capacity.
(06) Equal/Nequal routines use epsilons of 0.0000000001 and 0.000001
(06) The life-time of objects registered with a symbol-table must
span at least the life-time of expressions generated using
that symbol-table, otherwise the result will be undefined
behavior.
(07) Equal/Nequal routines use epsilons of 0.0000000001 and 0.000001
for double and float types respectively.
(07) All trigonometric functions assume radian input unless
(08) All trigonometric functions assume radian input unless
stated otherwise.
(08) Expressions may contain white-space characters such as
(09) Expressions may contain white-space characters such as
space, tabs, new-lines, control-feed et al.
('\n', '\r', '\t', '\b', '\v', '\f')
(09) Strings may be constructed from any letters, digits or special
(10) Strings may be constructed from any letters, digits or special
characters such as (~!@#$%^&*()[]|=+ ,./?<>;:"`~_), and must
be enclosed with single-quotes.
eg: 'Frankly, my dear, I don't give a damn!'
(10) User defined normal functions can have up to 20 parameters.
Where as user defined vararg-functions can have unlimited an
(11) User defined normal functions can have up to 20 parameters,
where as user defined vararg-functions can have an unlimited
number of parameters.
(11) The inbuilt polynomial functions can be at most of degree 12.
(12) The inbuilt polynomial functions can be at most of degree 12.
(12) Where appropriate constant folding optimisations will be
(13) Where appropriate constant folding optimisations will be
applied. (eg: The expression '2+(3-(x/y))' becomes '5-(x/y)')
(13) String processing capabilities are available by default.
(14) String processing capabilities are available by default.
To turn them off, the following needs to be defined at
compile time: exprtk_disable_string_capabilities
(14) Expressions may contain any of the following comment styles:
(15) Expressions may contain any of the following comment styles:
1. // .... \n
2. # .... \n
3. /* .... */
@ -449,6 +454,17 @@ correctly optimize such expressions for a given architecture.
#include "exprtk.hpp"
template <typename T>
struct myfunc : public exprtk::ifunction<T>
{
myfunc() : exprtk::ifunction<T>(2) {}
inline T operator()(const T& v1, const T& v2)
{
return T(1) + (v1 * v2) / T(3);
}
};
int main()
{
typedef exprtk::symbol_table<double> symbol_table_t;
@ -456,17 +472,20 @@ int main()
typedef exprtk::parser<double> parser_t;
typedef exprtk::parser_error::type error_t;
std::string expression_str = "z := 2 [sin(x/pi)^3 + cos(pi/y)^4]";
std::string expression_str = "z := 2 myfunc[4 + sin(x/pi)^3,y^2]";
double x = 1.1;
double y = 2.2;
double z = 3.3;
myfunc<double> mf;
symbol_table_t symbol_table;
symbol_table.add_constants();
symbol_table.add_variable("x",x);
symbol_table.add_variable("y",y);
symbol_table.add_variable("z",z);
symbol_table.add_function("myfunc",mf);
expression_t expression;
expression.register_symbol_table(symbol_table);