bridge/class-master/depend/pari/src/basemath/mellininv.c
/* Asymptotic expansion of the m-th derivative of inverse Mellin, to length
 * nlimmax. If status = 2, the asymptotic expansion is finite so return only
 * the necessary number of terms nlim <= nlimmax + d. */
Asymptotic expansion of the m-th derivative of inverse Mellin, to length
nlimmax. If status = 2, the asymptotic expansion is finite so return only
the necessary number of terms nlim <= nlimmax + d.
Asymptotic expansion of the m - th derivative of inverse Mellin to length nlimmax . If status = 2 the asymptotic expansion is finite so return only the necessary number of terms nlim < = nlimmax + d .
static GEN
gammamellininvasymp_i(GEN Vga, long nlimmax, long m, long *status)
{
  pari_sp ltop = avma;
  GEN M, A, Aadd;
  long d, i, nlim, n;
  M = Klargeinit0(Vga, nlimmax, status);
  if (!m) return gerepilecopy(ltop, M);
  d = lg(Vga)-1;
  A = gdivgs(gaddsg(1-d, vecsum(Vga)), 2*d);
  if (*status == 2) M = shallowconcat(M, zerovec(m));
  nlim = lg(M)-1;
  Aadd = gdivgs(stoi(2-d), 2*d); 
  for (i = 1; i <= m; i++, A = gadd(A,Aadd))
    for (n = nlim-1; n >= 1; --n)
      gel(M, n+1) = gsub(gel(M, n+1),
                         gmul(gel(M, n), gsub(A, gdivgs(stoi(n-1), d))));
  stripzeros(M);
  return gerepilecopy(ltop, M);
}
static GEN gammamellininvasymp_i ( GEN Vga , long nlimmax , long m , long * status ) { pari_sp ltop = avma ; GEN M , A , Aadd ; long d , i , nlim , n ; M = Klargeinit0 ( Vga , nlimmax , status ) ; if ( ! m ) return gerepilecopy ( ltop , M ) ; d = lg ( Vga ) - 1 ; A = gdivgs ( gaddsg ( 1 - d , vecsum ( Vga ) ) , 2 * d ) ; if ( * status == 2 ) M = shallowconcat ( M , zerovec ( m ) ) ; nlim = lg ( M ) - 1 ; Aadd = gdivgs ( stoi ( 2 - d ) , 2 * d ) ; for ( i = 1 ; i <= m ; i ++ , A = gadd ( A , Aadd ) ) for ( n = nlim - 1 ; n >= 1 ; -- n ) gel ( M , n + 1 ) = gsub ( gel ( M , n + 1 ) , gmul ( gel ( M , n ) , gsub ( A , gdivgs ( stoi ( n - 1 ) , d ) ) ) ) ; stripzeros ( M ) ; return gerepilecopy ( ltop , M ) ; }
Asymptotic expansion of the m-th derivative of inverse Mellin, to length
 nlimmax.
Asymptotic expansion of the m - th derivative of inverse Mellin to length nlimmax .
/* half the exponent of t in asymptotic expansion. */ /* (1/d) - (1/2) */