orthax.polyutils.mapparms

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

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

Returns:

offset, scale (scalars) – 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 orthax 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))