This function will shape an input signal to the given spectrum (simple, unregulated spectral shaping)
Syntax: [ y_shaped ] = shapeSpectrum( y, fs, spectrum )
Inputs:
y - Input signal in the time-domain which requires shaping.
spectrum - A vector containing the magnitude spectrum to shape the
signal with. ( length = fs/2 - 1 )
freqs - A vector containing the corresponding frequencies for the
spectrum vector.
Outputs:
y_shaped - The input signal shaped to the given spectrum