Usage

Compile the code by

make clean; make

Once the compilation is done, an executable named test_Ylm will be created. Run the test by

./test_Ylm <Lmax> <n>

Lmax is the maximum degree number for l, n is the number of random coordinates to test.

Note that the current tests work only for Lmax <= 6 since the reference answers for Lmax > 6 are not available. However, the sph_harmonics routine works for any non-negative integer Lmax.

For example, the following comand will generate 100000 random coordinates to test the spherical harmonics routines for l up to 3 and compare the results.

./test_Ylm 3 100000

The above command gives the following results:

l =  0, m =  0, error_lm = 0.000e+00
l =  1, m = -1, error_lm = 3.331e-16
l =  1, m =  0, error_lm = 4.441e-16
l =  1, m =  1, error_lm = 2.776e-16
l =  2, m = -2, error_lm = 4.441e-16
l =  2, m = -1, error_lm = 4.996e-16
l =  2, m =  0, error_lm = 5.375e-16
l =  2, m =  1, error_lm = 4.441e-16
l =  2, m =  2, error_lm = 1.617e-16
l =  3, m = -3, error_lm = 4.718e-16
l =  3, m = -2, error_lm = 6.661e-16
l =  3, m = -1, error_lm = 9.159e-16
l =  3, m =  0, error_lm = 5.551e-16
l =  3, m =  1, error_lm = 8.604e-16
l =  3, m =  2, error_lm = 2.470e-16
l =  3, m =  3, error_lm = 6.661e-16
Success! All tests passed!
===============
= Timing info =
===============
Run-time of sph_harmonics: 23.172 ms
Run-time of SPARC routine: 4.169 ms
Total run-time of the test: 45.258 ms