internal override Symbol PreEval(Symbol x)
{
var z = x.ToComplex();
var r = Math.exp(z.Re);
if (z.Im != 0.0)
{
return(new Complex(r * Math.cos(z.Im), r * Math.sin(z.Im)));
}
return(new Complex(r));
}
internal static void ifft_1d(double[] re, double[] im, int sign)
{
double u_r, u_i, w_r, w_i, t_r, t_i;
int ln, nv2, k, l, le, le1, j, ip, i, n;
n = re.Length;
ln = ( int )(Math.log(( double )n) / Math.log(2) + 0.5);
nv2 = n / 2;
j = 1;
for (i = 1; i < n; i++)
{
if (i < j)
{
t_r = re[i - 1];
t_i = im[i - 1];
re[i - 1] = re[j - 1];
im[i - 1] = im[j - 1];
re[j - 1] = t_r;
im[j - 1] = t_i;
}
k = nv2;
while (k < j)
{
j = j - k;
k = k / 2;
}
j = j + k;
}
for (l = 1; l <= ln; l++)
{
le = ( int )(Math.exp(( double )l * Math.log(2)) + 0.5);
le1 = le / 2;
u_r = 1.0;
u_i = 0.0;
w_r = Math.cos(Math.PI / ( double )le1);
w_i = sign * Math.sin(Math.PI / ( double )le1);
for (j = 1; j <= le1; j++)
{
for (i = j; i <= n; i += le)
{
ip = i + le1;
t_r = re[ip - 1] * u_r - u_i * im[ip - 1];
t_i = im[ip - 1] * u_r + u_i * re[ip - 1];
re[ip - 1] = re[i - 1] - t_r;
im[ip - 1] = im[i - 1] - t_i;
re[i - 1] = re[i - 1] + t_r;
im[i - 1] = im[i - 1] + t_i;
}
t_r = u_r * w_r - w_i * u_i;
u_i = w_r * u_i + w_i * u_r;
u_r = t_r;
}
}
if (sign > 0)
{
for (i = 0; i < n; i++)
{
re[i] /= n;
im[i] /= n;
}
}
}