# This file was *autogenerated* from the file ./legendre.sage
from sage.all_cmdline import *   # import sage library

_sage_const_2 = Integer(2); _sage_const_1 = Integer(1); _sage_const_0 = Integer(0); _sage_const_20 = Integer(20); _sage_const_1En14 = RealNumber('1E-14')#!/usr/bin/sage

# Schmidt Quasi-Normalized Legendre Functions for Spherical Harmonics

x = var('x');

def polypart(n,m):
    pol = (x**_sage_const_2 -_sage_const_1 )**n
    for I in range(_sage_const_1 ,n+_sage_const_1 ):
        pol = diff(pol,x)
    for I in range(_sage_const_1 ,m+_sage_const_1 ):
        pol = diff(pol,x)
    return pol

def normpart(n,m):
    if(m==_sage_const_0 ):
        nrm = _sage_const_1 /_sage_const_2 **n/factorial(n)
    else:
        nrm = (_sage_const_1 /_sage_const_2 **n/factorial(n)) * sqrt(_sage_const_2 *factorial(n-m)/factorial(n+m))
    return nrm

NN = _sage_const_20 


lns = []
coefs = []
nmaxcoefs = _sage_const_0 
for I in range(_sage_const_0 ,NN+_sage_const_1 ):
    for J in range(_sage_const_0 ,I+_sage_const_1 ):
        pol = polypart(I,J)
        nrm = normpart(I,J)
        pol2 = expand(pol)
        p2c = pol2.coefficients(sparse=False)

        pol3 = nrm*pol2
        p3c = pol3.coefficients(sparse=False)
        for K in range(_sage_const_0 ,len(p3c)):
            p3c[K] = p3c[K].n()

        coefs.append(p3c)
        if(nmaxcoefs<len(p3c)):
            nmaxcoefs = len(p3c)
        
        #print("{:d}\t{:d}\t{}\t\t{}".format(I,J,nrm,p2c))
        
        s = ""
        s = s + "{:d}\t{:d}\t".format(I,J)
        for K in range(_sage_const_0 ,len(p3c)):
            nn = p3c[K]
            if(abs(nn)<_sage_const_1En14 ):
                nn = _sage_const_0 
            s = s + "{:1.8g}\t".format(nn)
        s = s + "\n"
        print(s)
        lns.append(s)

##C style coefficient output

fout = "c_legendrecoefs.c"
fp = open(fout,"w+")


pref1 = "static const int amslegendre_ndegree = {:d};\n".format(NN)
pref2 = "static const int amslegendre_maxporder = {:d};\n".format(nmaxcoefs-_sage_const_1 )
pref = pref1 + pref2 + "static const float amslegendrecoefs[] = { \n"

for I in range(_sage_const_0 ,NN+_sage_const_1 ):
    for J in range(_sage_const_0 ,I+_sage_const_1 ):
        ind = I*(I+_sage_const_1 )/_sage_const_2 +J
        for K in range(_sage_const_0 ,nmaxcoefs):
            if(K<len(coefs[ind])):
                nn = coefs[ind][K]
                if(abs(nn)<_sage_const_1En14 ):
                    nn = _sage_const_0 
            else:
                nn = _sage_const_0 
            
            if(ind<len(coefs)-_sage_const_1 ):
                if(K<nmaxcoefs-_sage_const_1 ):
                    pref = pref + "{:1.8g},".format(nn)
                else:
                    pref = pref + "{:1.8g},\n".format(nn)
            else:
                if(K<nmaxcoefs-_sage_const_1 ):
                    pref = pref + "{:1.8g},".format(nn)
                else:
                    pref = pref + "{:1.8g}".format(nn) + "\n};\n\n"

fp.writelines(pref)
fp.close()