To use one of the GSL modules in a S-lang script, the module must
first be loaded using the require
function. For example, to
load the GSL special function module, use
require ("gslsf");
The gsl.sl
file exists as a convenient way to load
all GSL modules (gslsf
, gslrand
, etc.), e.g.,
require ("gsl");
Finally, it may be desirable to import the GSL module into a separate
namespace. For example, to load the GSL special function module
gslsf
into a namespace called GSL
, use
require ("gsl", "G")
Then to access, e.g., the hypot
function, use the
GSL->hypot
. See the
S-Lang documentation for more information
about namespaces.
Once the desired module has been loaded, intrinsics functions and variables defined by the module may be used in the usual way, e.g.,
require ("gslsf");
.
.
% Use the GSL hypot function to filter a list of (x,y) pairs
% to those values that fall in a circle of radius R centered
% on (0,0)
define filter_region_in_circle (x, y, R)
{
variable i = where (hypot (x,y) < R);
return (x[i], y[i]);
}