In LV51 it is built in. I have not seen any readily available examples
online.
In matlab basic spectrogram is calculated as follows (note that this is from
their manual).
specgram calculates the spectrogram for a given signal as follows:
1. It splits the signal into overlapping sections and applies the window
specified by the window parameter to each section.
2. It computes the discrete-time Fourier transform of each section with
a length nfft FFT to produce an estimate of the short-term frequency content
of the signal; these transforms make up the columns of B. specgram zero pads
the windowed sections if nfft > length(window), so the quantity
(length(window) - noverlap) specifies by how many samples specgram shifts
the window.
3. For real input, specgram truncat
es the spectrogram to the first
nfft/2 + 1 points for nfft even and (nfft + 1)/2 for nfft odd.
wrote in message news:3803FC17.1369@prodigy.net...
> Hello,
>
> I am looking for a simple VI which calculates and displays spectrograms
> of time-domain data. It is most useful for non-stationary signals such
> as voice and similar data. Any pointers would be helpful. (I know
> about the Joint Time-Freq toolkit offered by national, but that is
> overkill, and $$$). Please email me direct. Thanks
>
> Calvin
>
> calvinf15@prodigy.net
