Feature Overview

Optimized for speed
  • High parsing performance; Bulk mode offers parallelization of expression evaluation.
  • if-then-else operator with lazy evaluation
  • Compute multiple comma separated subexpressions in a single evaluation: sin(x), x+y, x*x
Supported operators
  • 14 predefined operators.
  • binary operators are user definable
  • postfix operators are user definable
  • infix operators are user definable
Supported functions
  • 25 predefined functions.
  • with a fixed number of up to five arguments
  • with variable number of arguments
  • with a single string argument (for database queries)
  • Can be extended by a user
User-defined constants.
  • numeric constants
  • string constants
User-defined variables.
  • unlimited in number
  • definable at parser runtime by the parser: abc=123
  • assigning variables in terms of other variables is possible
Custom value recognition callbacks

You can define how a value looks like. You can make muparser to read hex values like a=0x00ff00 or binary values. a=0b1000101. You could also use this feature to Query values from a database.

Other features
  • Use postfix operators as unit multipliers (3m -> 0.003)
  • Built in function for numerical differentiation with respect to a given variable.
  • Argument separator, decimal separator, thousands separator can be adjusted to your locale
  • CMake based build system
  • ISO 14882:2017 compliant code
  • DLL version usable from every language able to use function exported in C-style

Built-in functions

The following table gives an overview of the functions supported by the default implementation. It lists the function names, the number of arguments and a brief description.

Name Argc. Explanation
sin 1 sine function
cos 1 cosine function
tan 1 tangens function
asin 1 arcus sine function
acos 1 arcus cosine function
atan 1 arcus tangens function
sinh 1 hyperbolic sine function
cosh 1 hyperbolic cosine
tanh 1 hyperbolic tangens function
asinh 1 hyperbolic arcus sine function
acosh 1 hyperbolic arcus tangens function
atanh 1 hyperbolic arcur tangens function
log2 1 logarithm to the base 2
log10 1 logarithm to the base 10
log 1 logarithm to base e (2.71828...)
ln 1 logarithm to base e (2.71828...)
exp 1 e raised to the power of x
sqrt 1 square root of a value
sign 1 sign function -1 if x<0; 1 if x>0
rint 1 round to nearest integer
abs 1 absolute value
min var. min of all arguments
max var. max of all arguments
sum var. sum of all arguments
avg var. mean value of all arguments

Built-in binary operators

The following table lists the default binary operators supported by the parser.

Operator Description Priority
= assignement * -1
&& logical and 1
|| logical or 2
<= less or equal 4
>= greater or equal 4
!= not equal 4
== equal 4
> greater than 4
< less than 4
+ addition 5
- subtraction 5
* multiplication 6
/ division 6
^ raise x to the power of y 7
* The assignment operator is special since it changes one of its arguments and can only by applied to variables.

Ternary Operators

muparser has built in support for the if then else operator. It uses lazy evaluation in order to make sure only the necessary branch of the expression is evaluated.

Operator Description Remarks
?: if then else operator C++ style syntax