Compute the N-dimensional discrete Fourier Transform for real input. This function computes the N-dimensional discrete Fourier Transform over any number of axes in an M-dimensional real array by means of the Fast Fourier Transform (FFT). By default, all axes are transformed, with
(a, s=None, axes=None, norm=None)
| 1109 | |
| 1110 | @array_function_dispatch(_fftn_dispatcher) |
| 1111 | def rfftn(a, s=None, axes=None, norm=None): |
| 1112 | """ |
| 1113 | Compute the N-dimensional discrete Fourier Transform for real input. |
| 1114 | |
| 1115 | This function computes the N-dimensional discrete Fourier Transform over |
| 1116 | any number of axes in an M-dimensional real array by means of the Fast |
| 1117 | Fourier Transform (FFT). By default, all axes are transformed, with the |
| 1118 | real transform performed over the last axis, while the remaining |
| 1119 | transforms are complex. |
| 1120 | |
| 1121 | Parameters |
| 1122 | ---------- |
| 1123 | a : array_like |
| 1124 | Input array, taken to be real. |
| 1125 | s : sequence of ints, optional |
| 1126 | Shape (length along each transformed axis) to use from the input. |
| 1127 | (``s[0]`` refers to axis 0, ``s[1]`` to axis 1, etc.). |
| 1128 | The final element of `s` corresponds to `n` for ``rfft(x, n)``, while |
| 1129 | for the remaining axes, it corresponds to `n` for ``fft(x, n)``. |
| 1130 | Along any axis, if the given shape is smaller than that of the input, |
| 1131 | the input is cropped. If it is larger, the input is padded with zeros. |
| 1132 | if `s` is not given, the shape of the input along the axes specified |
| 1133 | by `axes` is used. |
| 1134 | axes : sequence of ints, optional |
| 1135 | Axes over which to compute the FFT. If not given, the last ``len(s)`` |
| 1136 | axes are used, or all axes if `s` is also not specified. |
| 1137 | norm : {"backward", "ortho", "forward"}, optional |
| 1138 | .. versionadded:: 1.10.0 |
| 1139 | |
| 1140 | Normalization mode (see `numpy.fft`). Default is "backward". |
| 1141 | Indicates which direction of the forward/backward pair of transforms |
| 1142 | is scaled and with what normalization factor. |
| 1143 | |
| 1144 | .. versionadded:: 1.20.0 |
| 1145 | |
| 1146 | The "backward", "forward" values were added. |
| 1147 | |
| 1148 | Returns |
| 1149 | ------- |
| 1150 | out : complex ndarray |
| 1151 | The truncated or zero-padded input, transformed along the axes |
| 1152 | indicated by `axes`, or by a combination of `s` and `a`, |
| 1153 | as explained in the parameters section above. |
| 1154 | The length of the last axis transformed will be ``s[-1]//2+1``, |
| 1155 | while the remaining transformed axes will have lengths according to |
| 1156 | `s`, or unchanged from the input. |
| 1157 | |
| 1158 | Raises |
| 1159 | ------ |
| 1160 | ValueError |
| 1161 | If `s` and `axes` have different length. |
| 1162 | IndexError |
| 1163 | If an element of `axes` is larger than than the number of axes of `a`. |
| 1164 | |
| 1165 | See Also |
| 1166 | -------- |
| 1167 | irfftn : The inverse of `rfftn`, i.e. the inverse of the n-dimensional FFT |
| 1168 | of real input. |
no test coverage detected