r_util

stistools.r_util.expandFileName(filename)

Expand environment variable in a file name.

If the input file name begins with either a Unix-style or IRAF-style environment variable (e.g. $lref/name_dqi.fits or lref$name_dqi.fits respectively), this routine expands the variable and returns a complete path name for the file.

Parameters:
filenamestr

A file name, possibly including an environment variable.

Returns:
fullnamestr

The file name with environment variable expanded.

stistools.r_util.interpolate(x, values, xp)

Interpolate.

Linear interpolation is used. If the specified indpendent variable value xp is outside the range of the array x, the first (or last) value in values will be returned.

Parameters:
xa sequence object, e.g. an array, int or float

Array of independent variable values.

valuesa sequence object, e.g. an array (not character)

Array of dependent variable values.

xpint or float

Independent variable value at which to interpolate.

Returns:
interp_valsthe same type as one element of values

Linearly interpolated value.