00001 #ifndef __DERIVATIVE__
00002 #define __DERIVATIVE__
00003
00049 namespace FFT{
00050
00055 template <typename Complex_data_2D_array>
00056 void x_derivative(const Complex_data_2D_array& source,
00057 Complex_data_2D_array* const result);
00058
00063 template <typename Complex_data_2D_array>
00064 void y_derivative(const Complex_data_2D_array& source,
00065 Complex_data_2D_array* const result);
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00084
00085 template <typename Complex_data_2D_array>
00086 void x_derivative(const Complex_data_2D_array& source,
00087 Complex_data_2D_array* const result){
00088
00089 typedef typename Complex_data_2D_array::value_type complex_type;
00090 typedef float real_type;
00091 typedef unsigned int size_type;
00092
00093 const size_type width = source.x_size();
00094 const size_type height = source.y_size();
00095 const size_type half_width = width/2;
00096
00097 if ((result->x_size()!=width)||(result->y_size()!=height)){
00098 result->resize(width,height);
00099 }
00100
00101 for(size_type x=0;x<width;x++){
00102 for(size_type y=0;y<height;y++){
00103
00104 const real_type X = static_cast<real_type>(x) -
00105 width*((x+half_width)/width);
00106
00107 (*result)(x,y) = complex_type(0,2*M_PI*X/width)*source(x,y);
00108 }
00109 }
00110
00111 }
00112
00113
00114 template <typename Complex_data_2D_array>
00115 void y_derivative(const Complex_data_2D_array& source,
00116 Complex_data_2D_array* const result){
00117
00118 typedef typename Complex_data_2D_array::value_type complex_type;
00119 typedef float real_type;
00120 typedef unsigned int size_type;
00121
00122 const size_type width = source.x_size();
00123 const size_type height = source.y_size();
00124 const size_type half_width = width/2;
00125
00126 if ((result->x_size()!=width)||(result->y_size()!=height)){
00127 result->resize(width,height);
00128 }
00129
00130 for(size_type x=0;x<width;x++){
00131 for(size_type y=0;y<height;y++){
00132
00133 const real_type Y = static_cast<real_type>(y);
00134
00135 (*result)(x,y) = complex_type(0,2*M_PI*Y/height)*source(x,y);
00136 }
00137 }
00138
00139 }
00140
00141 }
00142
00143 #endif
