# Grid test.m

From Spinach Documentation Wiki

Plots grid integration quality as a function of spherical rank.

## Syntax

grid_profile=grid_test(alphas,betas,gammas,weights,max_rank,sfun)

## Description

The quality of a grid is defined as the norm of the residual of spherical harmonics or Wigner functions integrated using the grid provided.

## Arguments

alphas - alpha Euler angles of the grid, in radians, zeros for single-angle grids betas - beta Euler angles of the grid, in radians gammas - gamma Euler angles of the grid, in radians, zeros for two-angle grids weights - point weights of the grid max_rank - maximum spherical rank to consider sfun - spherical function type: for three-angle grids use 'D_lmn', for two-angle grids use 'Y_lm', for single-angle grids use 'Y_l0'.

## Returns

grid_profile - a vector of residual norms in each spherical rank

The function also produces a figure showing the absolute value of the integration residual as a function of the spherical rank.

## Examples

## Notes

A good grid produces near-zero answers for as many spherical ranks as possible.

## See also

grid_kron.m, repulsion.m, shrewd.m, wigner.m, spher_harmon.m

*Version 1.10, authors: Ilya Kuprov*