# fftfreqconvmx

##### Internal: Convert FFT frequency bins to Bark/Mel bins

Generate a matrix of weights to combine FFT bins into Bark/Mel bins.

- Keywords
- internal

##### Usage

```
fft2barkmx(nfft, sr = 8000, nfilts = NULL, width = 1, minfreq = 0,
maxfreq = sr/2)
fft2melmx(nfft, sr = 8000, nfilts = 40, width = 1, minfreq = 0,
maxfreq = sr/2, htkmel = FALSE, constamp = FALSE)
```

##### Arguments

- nfft
Source FFT size.

- sr
Sampling rate of the signal.

- nfilts
Number of desired output frequency bands. If

`NULL`

then one per Bark/Mel between`minfreq`

and`maxfreq`

.- width
Width of each output frequency band in Bark/Mel.

- minfreq
Minimum frequency.

- maxfreq
Maximum frequency.

- htkmel
Use HTK- or Slaney's curve of the Melscale.

- constamp
Make integration windows peak at 1 (

`constamp=TRUE`

) or sum to 1 (`constamp=FALSE`

)

##### Value

The weight matrix with 'nfft' columns and 'nfilts' rows.

Edge frequencies of the bins.

##### Note

While wts has nfft columns, the second half are all zero.
Hence, Bark spectrum is `fft2barkmx(nfft, sr) %*% abs(fft(xincols, nfft))`

.

##### References

Daniel P. W. Ellis: http://www.ee.columbia.edu/~dpwe/resources/matlab/rastamat/, Malcolm Slaney: Auditory Toolbox http://cobweb.ecn.purdue.edu/~malcolm/interval/1998-010/

##### See Also

##### Examples

```
# NOT RUN {
#Mel matrix in Slaney's mfcc.m:
#tuneR:::fft2melmx(512, 8000, 40, 1, 133.33, 6855.5, FALSE, FALSE)
# }
```

*Documentation reproduced from package tuneR, version 1.3.3, License: GPL-2 | GPL-3*