Added function to calculate absolute value of ulm2

Samo Penic

2018-06-26 0661f62a1a4b5bc87310421d198e7df8538c7363

 src/shcomplex.c

@@ -171,3 +171,9 @@
    
    return retval;
}


ts_double get_absolute_ulm2(ts_vesicle *vesicle, int l, int m){
   return gsl_complex_abs2(vesicle->sphHarmonics->ulmComplex[l][m]);
}