texinode(The mathfunc Module)(The parameter Module)(The mapfile Module)(Zsh Modules)
sect(The mathfunc Module)
cindex(functions, mathematical)
cindex(mathematical functions)
The tt(mathfunc) module provides standard mathematical functions for use when
evaluating mathematical formulae.  The syntax agrees with normal C and
FORTRAN conventions, for example,

example((( f = sin(0.3) )))

assigns the sine of 0.3 to the parameter f.

Most functions take floating point arguments and return a floating point
value.  However, any necessary conversions from or to integer type will be
performed automatically by the shell.  Apart from tt(atan) with a second
argument and the tt(abs), tt(int) and tt(float) functions, all functions
behave as noted in the manual page for the corresponding C function,
except that any arguments out of range for the function in question will be
detected by the shell and an error reported.

The following functions take a single floating point argument: tt(acos),
tt(acosh), tt(asin), tt(asinh), tt(atan), tt(atanh), tt(cbrt), tt(ceil),
tt(cos), tt(cosh), tt(erf), tt(erfc), tt(exp), tt(expm1), tt(fabs),
tt(floor), tt(gamma), tt(j0), tt(j1), tt(lgamma), tt(log), tt(log10),
tt(log1p), tt(logb), tt(sin), tt(sinh), tt(sqrt), tt(tan), tt(tanh),
tt(y0), tt(y1).  The tt(atan) function can optionally take a second
argument, in which case it behaves like the C function tt(atan2).
The tt(ilogb) function takes a single floating point argument, but
returns an integer.

The function tt(signgam) takes no arguments, and returns an integer, which
is the C variable of the same name, as described in manref(gamma)(3).  Note
that it is therefore only useful immediately after a call to tt(gamma) or
tt(lgamma).  Note also that `tt(signgam())' and `tt(signgam)' are distinct
expresssions.

The following functions take two floating point arguments: tt(copysign),
tt(drem), tt(fmod), tt(hypot), tt(nextafter).

The following take an integer first argument and a floating point second
argument: tt(jn), tt(yn).

The following take a floating point first argument and an integer second
argument: tt(ldexp), tt(scalb).

The function tt(abs) does not convert the type of its single argument; it
returns the absolute value of either a floating point number or an
integer.  The functions tt(float) and tt(int) convert their arguments into
a floating point or integer value (by truncation) respectively.

Note that the C tt(pow) function is available in ordinary math evaluation
as the `tt(**)' operator and is not provided here.