Fixed issue with first slag basis

Author: Boris Leistedt

src/main/c/flag_spherbessel.c

@@ -84,7 +84,7 @@ void flag_sbesselslag(double *sbesselslag, int ell, double *kvalues, int Nk, int
         if( j == 0 ){
           weight =  pow(2, 2) * gsl_sf_fact(ell + 2) * (n + 1.0) * (n + 2.0) / 2.0 ; // 
         }else{
-          weight = - 2 * (n - j + 1) * weight / ((j + 2)); //  
+          weight = - 2 * (ell + 2 + j) * (n - j + 1) * weight / (j * (j + 2)); //  
         }
         //sbesselslag[n * Nk + k] += pow((n+1)*(n+2), -0.5) * weight * mulk_coefs[j+2] ;
         printf(" %3.0e ",weight);

src/main/c/flag_spherlaguerre.c

@@ -444,6 +444,7 @@ void flag_spherlaguerre_mapped_synthesis(complex double *f, const complex double
 void flag_spherlaguerre_basis(double *KN, const int N, const double *nodes, int Nnodes, double tau)
 {
 	assert(Nnodes > 0);
+	assert(N > 0);
 	int i, n;
 	const int alpha = 2;
 	double factor, lagu0, lagu1, lagu2, r;
@@ -456,11 +457,9 @@ void flag_spherlaguerre_basis(double *KN, const int N, const double *nodes, int
 		lagu0 = 0.0;
 		lagu1 = 1.0;
 
-		if (N == 0 ){
+		KN[i * N] = factor * pow(factorial_range(1, alpha), -0.5) * lagu1;
 
-			KN[i] = factor * pow(factorial_range(1, alpha), -0.5) * lagu1;
-		
-		} else {
+		if ( N > 1 ) {
 
 			for (n = 1; n < N; n++) 
 			{