numpy.polynomial.polyutils.mapparms

polynomial.polyutils.mapparms(old, new)[source]

Linear map parameters between domains.

Return the parameters of the linear map offset + scale*x that maps old to new such that old[i] -> new[i], i = 0, 1.

Parameters

old, newarray_like

Domains. Each domain must (successfully) convert to a 1-d array containing precisely two values.

Returns

offset, scalescalars

The map L(x) = offset + scale*x maps the first domain to the second.

See also

getdomain, mapdomain

Notes

Also works for complex numbers, and thus can be used to calculate the parameters required to map any line in the complex plane to any other line therein.

Examples

>>> from numpy.polynomial import polyutils as pu
>>> pu.mapparms((-1,1),(-1,1))
(0.0, 1.0)
>>> pu.mapparms((1,-1),(-1,1))
(-0.0, -1.0)
>>> i = complex(0,1)
>>> pu.mapparms((-i,-1),(1,i))
((1+1j), (1-0j))