public static Complex2D idft_2D(Complex2D src)
{
int width = src.Width;
int height = src.Height;
return(fft_2D_core(src, ref width, ref height, -1));
}
// 2维快速傅里叶变换
// 作者：死猫
// int width, int height：欲变换数据的长度和宽度，函数调用后此值更改为实际变换长度
// int flag：区分fft或dtft，为1为fft，为-1为idft
private static Complex2D fft_2D_core(Complex2D src, ref int width, ref int height, int flag)
{
//补零后长度
int width_Log2N = ReLog2N(width);
int height_Log2N = ReLog2N(height);
int Relog2N = Math.Max(width_Log2N, height_Log2N);
int ReWidth = 0x01 << Relog2N;
int ReHeight = 0x01 << Relog2N;
//重新复制数据，清零
Complex2D ReList2D = new Complex2D(ReWidth, ReHeight);
ReList2D.Clear();
int width_temp = Math.Min(src.Width, width);
int height_temp = Math.Min(src.Height, height);
for (int i = 0; i < height_temp; i++)
{
for (int j = 0; j < width_temp; j++)
{
ReList2D[i, j] = new Complex(src[i, j].Re, src[i, j].Im);
}
}
ComplexList Xn;
ComplexList Xk;
int Lenght_temp;
//第1遍fft
for (int i = 0; i < ReHeight; i++)
{
Xn = ReList2D.GetRow(i);
Lenght_temp = Xn.Lenght;
Xk = fft_core(Xn, ref Lenght_temp, flag);
ReList2D.SetRow(i, Xk);
}
//第2遍fft
for (int i = 0; i < ReWidth; i++)
{
Xn = ReList2D.GetColumn(i);
Lenght_temp = Xn.Lenght;
Xk = fft_core(Xn, ref Lenght_temp, flag);
ReList2D.SetColumn(i, Xk);
}
//赋值
width = ReWidth;
height = ReHeight;
//清理内存
//Xn = null;
//Xk = null;
//GC.Collect();
//返回
return(ReList2D);
}
public Complex2D GetAmplitude()
{
Complex2D ret = new Complex2D(Width, Height);
for (int i = 0; i < Height; i++)
{
for (int j = 0; j < Width; j++)
{
ret[i, j] = new Complex(this[i, j].Modulus());
}
}
return(ret);
}
public static Complex2D 延拓(Complex2D frqData, double 延拓高度)
{
int height = frqData.Height;
int whith = frqData.Width;
var 延拓结果 = new Complex2D(height, whith);
var coex = Coeff(whith, xtick);
var coey = Coeff(height, ytick);
for (int i = 0; i < height; i++)
{
for (int j = 0; j < whith; j++)
{
var a = Math.Sqrt(coey[i] * coey[i] + coex[j] * coex[j]) * 延拓高度;
延拓结果[i, j] = frqData[i, j] * Math.Exp(a);
}
}
return(延拓结果);
}
public static Complex2D Zdrf(Complex2D frqData)
{
int height = frqData.Height;
int whith = frqData.Width;
var zdrfData = new Complex2D(height, whith);
var coex = Coeff(whith, xtick);
var coey = Coeff(height, ytick);
for (int i = 0; i < height; i++)
{
for (int j = 0; j < whith; j++)
{
var a = Math.Sqrt(coey[i] * coey[i] + coex[j] * coex[j]);
zdrfData[i, j] = a * frqData[i, j];
}
}
return(zdrfData);
}
public static Complex2D Ydrf(Complex2D frqData)
{
int height = frqData.Height;
int whith = frqData.Width;
var ydrfData = new Complex2D(height, whith);
//var coex = Coeff(whith, xtick);
var coey = Coeff(height, ytick);
var im = new Complex(0, 1);
for (int i = 0; i < height; i++)
{
for (int j = 0; j < whith; j++)
{
//var a = 2.0 * Math.PI * Math.Sqrt(coey[i] * coey[i] + coex[j] * coex[j]);
ydrfData[i, j] = coey[i] * frqData[i, j] * im;
}
}
return(ydrfData);
}
private void OpenFile(object parameter)
{
var ofd = new OpenFileDialog
{
Filter = "Grid|*.grd"
};
if (ofd.ShowDialog() == true)
{
int rows, cols;
double xtick, ytick, zmin, zmax;
var para = Convert.ToString(parameter);
if (para == "Anomaly")
{
anomalyData = OpenFile(ofd.OpenFile(), out rows, out cols, out xtick, out ytick, out zmin, out zmax);
AnomalyMin = zmin;
AnomalyMax = zmax;
AnomalyMap = GetMap(anomalyData, zmin, zmax);
EdgeDetection.Initialize(cols, rows, xtick, ytick, anomalyData);
frqData = null;
xdrData = null;
ydrData = null;
zdrData = null;
xdrfData = null;
ydrfData = null;
zdrfData = null;
vxxData = null;
vyyData = null;
vxyData = null;
}
else if (para == "Local")
{
secondData = OpenFile(ofd.OpenFile(), out rows, out cols, out xtick, out ytick, out zmin, out zmax);
SecondMin = zmin;
SecondMax = zmax;
SedondMap = GetMap(secondData, zmin, zmax);
}
}
}
public static Complex2D Vxy(Complex2D frqData)
{
int height = frqData.Height;
int whith = frqData.Width;
var VxyData = new Complex2D(height, whith);
var coex = Coeff(whith, xtick);
var coey = Coeff(height, ytick);
for (int i = 0; i < height; i++)
{
for (int j = 0; j < whith; j++)
{
VxyData[i, j] = -coey[i] * coex[j] * frqData[i, j] / Math.Sqrt(coey[i] * coey[i] + coex[j] * coex[j]);
}
}
VxyData[0, 0] = new Complex(0, 0);
VxyData[height / 2, 0] = new Complex(0, 0);
VxyData[0, whith / 2] = new Complex(0, 0);
VxyData[height / 2, whith / 2] = new Complex(0, 0);
return(VxyData);
}
