This invention is a data processing/visualization method which includes the software development and operation to apply to any multi-dimensional separation. The GC-MS analysis of diesel is an example to demonstrate this software development and operation. The steps of this method includes (1) displaying the total ion chromatogram obtained from a GC-MS experiment, (2) displaying each mass spectrum versus retention time, (3) selecting a normal paraffin family as the reference compound family for relative polarity display, (4) transforming every mass slice to line-up normal paraffin compound family in the same relative retention time (position), (5) rotating the axis to best display the two (multi) dimensional data.