plotfft(coef); plotfft(coef,fs);
plotfft(coef) plots the output from the fft function. The frequency axis will use normalized frequencies between 0 and 1 (the Nyquist frequency).
plotfft(coef,fs) does the same for the FFT of a signal sampled at a sampling rate of fs Hz.
plotfft(coef,fs,dynrange) additionally limits the dynamic range of the plot. See the description of the 'dynrange' parameter below.
plotfft accepts the following optional arguments:
| 'dynrange',r | Limit the dynamical range to r by using a colormap in the interval [chigh-r,chigh], where chigh is the highest value in the plot. The default value of [] means to not limit the dynamical range. |
| 'db' | Apply \(20\cdot \log_{10}\) to the coefficients. This makes it possible to see very weak phenomena, but it might show too much noise. This is the default. |
| 'dbsq' | Apply \(10\cdot \log_{10}\) to the coefficients. Same as the 'db' option, but assumes that the input is already squared. |
| 'lin' | Show the coefficients on a linear scale. This will display the raw input without any modifications. Only works for real-valued input. |
| 'linsq' | Show the square of the coefficients on a linear scale. |
| 'linabs' | Show the absolute value of the coefficients on a linear scale. |
| 'nf' | Display negative frequencies, with the zero-frequency centered in the middle. This is the default. |
| 'posfreq' | Display only the positive frequencies. |
| 'dim',dim | If coef is multidimensional, dim indicates the dimension along which are the individual channels oriented. Value 1 indicates columns, value 2 rows. |
| 'flog' | Use logarithmic scale for the frequency axis. This flag is only valid in conjuction with the 'posfreq' flag. |
In addition to these parameters, plotfft accepts any of the flags from setnorm. The coefficients will be normalized as specified before plotting.