A process is disclosed for determining the number of components in peaks, bands and signals of chromatograms, electrograms and spectrograms of all types obtained for purposes of analysis and substance separation in spectrograms of all types wherever energy-correlated measurement values as a function of an evolving parameter are formed and decomposed again. The problem addressed by the invention is that of designing a simple process. This problem is solved in that the different energy-correlated measurement values of a family of such measurement values produced from such a parameter are mutually related, so that characteristic geometric figures are obtained in which the originating evolving parameters are no longer contained. The thus obtained figures are gradually reduced, depending on their complexity, into straight lines, then into points. The number of components which contribute to the peaks and thus the composition of the total spectrogram in terms of the elements that make it up are obtained by the most simple manner, as well as the composition of the mixture of substances to be analysed and/or separated,.