map2map
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Create a x/y-map with fixed grid (dx and dy is constant) from a x/y-map with varying grid. This function was implemented to display spectrograms with varying hopsize dt and frequency resolution df.
- Usage 1
map2map(type, x, nc)- type
- this argument must be set to 0; it will be used in future to select the format of the input data and/or the remapping algorithm
- x
- a NxM matrix containing the input map
- nc
- a vector with length N; the value nc[i] specifies the number of used columns in the row x[i,*] of the input map
2 ≤ nc[i] ≤ M; with: i=0..N-1
- Description
- Each row i of the input map contains a data vector {x[i,0], .., x[i,nc[i]-1]}. A linear interpolation is used to expand all vectors to the length M.
- Example
- x contains a spectrogram. The spectra are computed with constant hopsize, but different transformation length. The length of each spectrum x[i,*] is stored in nc[i].
- Result 1
- A NxM matrix containing the interpolated map y.
- Usage 2
map2map(type, x, nc, pr)- type, x, nc
- see Usage 1
- pr
- a vector with length N; the value pr[i] specifies the relative position of the function stored in the row x[i,*] of the input map.
pr[0] < pr[1] < .. < pr[N-1]
- Description
- First the vectors x[i,*] are expanded as described above. In the second step interpolated rows are inserted to create a map with equidistant rows. The number of rows L of the interpolated map y depends on the range of the pr values and the minimum distance of two neighboring values of pr.
L = (pr[N-1] - pr[0]) / min(pr[i] - pr[i-1])- Example
- x contains a spectrogram. The spectra stored in the columns of x are computed with varying hopsize and transformation length. The length of each spectrum x[i,*] is stored in nc[i] and the value pr[i] is set to the center position of the i-th analysis window.
- Result 2
- A LxM matrix containing the interpolated map y.
