lsst.astshim  22.0.0+01bcf6a671
Classes | Functions
astshim.test Namespace Reference

Classes

class  ObjectTestCase
 
class  MappingTestCase
 

Functions

def makePolyMapCoeffs (nIn, nOut)
 
def makeTwoWayPolyMap (nIn, nOut)
 
def makeForwardPolyMap (nIn, nOut)
 

Function Documentation

◆ makeForwardPolyMap()

def astshim.test.makeForwardPolyMap (   nIn,
  nOut 
)
Make an astshim.PolyMap suitable for testing

The forward transform is the same as for `makeTwoWayPolyMap`.
This map does not have a reverse transform.

The equation is chosen for the following reasons:
- It is well defined for any positive value of nIn, nOut.
- It stays small for small x, to avoid wraparound of angles for
  SpherePoint endpoints.

◆ makePolyMapCoeffs()

def astshim.test.makePolyMapCoeffs (   nIn,
  nOut 
)
Make an array of coefficients for astshim.PolyMap for the following
equation:

fj(x) = C0j x0^2 + C1j x1^2 + C2j x2^2 + ... + CNj xN^2
where:
* i ranges from 0 to N=nIn-1
* j ranges from 0 to nOut-1,
* Cij = 0.001 (i+j+1)

◆ makeTwoWayPolyMap()

def astshim.test.makeTwoWayPolyMap (   nIn,
  nOut 
)
Make an astshim.PolyMap suitable for testing

The forward transform is as follows:
fj(x) = C0j x0^2 + C1j x1^2 + C2j x2^2 + ...
        + CNj xN^2 where Cij = 0.001 (i+j+1)

The reverse transform is the same equation with i and j reversed
thus it is NOT the inverse of the forward direction,
but is something that can be easily evaluated.

The equation is chosen for the following reasons:
- It is well defined for any positive value of nIn, nOut.
- It stays small for small x, to avoid wraparound of angles for
  SpherePoint endpoints.