Special Functionality Routines

LimitBandwidth(grid, lmax, lmin=0, norm=4, csphase=1)

This convenience routine returns a grid which contains degrees lmin to lmax of the input grid. Basically, it first decoposes the input grid by making a call to SHExpandDH , then sets all coefficients outside the range to zero and then issues a call to MakeGrid2D to recompose the coefficients.

Parameters:

• grid (numpy array) – A 2D grid
• lmax (int) – maximum spherical harmonic degree of decomposition
• lmin (int) – minimum spherical harmonic degree of decomposition
• norm (int) – spherical harmonic normalization
• csphase (int) – Condon-Shortley phase factor

Returns:

2D grid which is band-limited between lmin and lmax

Return type:

numpy array