Solution 6.6 - Chemometrics: Data Analysis for the Laboratory and Chemical Plant

1 and 2. The graph with the peaks with an overall intensity of greater than 10% of the maximum labelled is presented below. 10% of the maximum sum is 3983 and 43 wavelengths are identified, this simply removes uninteresting wavelengths.

3. The points lie roughly on a triangle. Note that this will only occur if there is very low noise and all spectra have some significant intensities throughout the region, otherwise it is necessary to remove low intensity wavelengths prior to performing PCA. The most diagnostic wavelengths are at the corners and appear to be 720, 768 and 832 cm^-1.

4. This is simply a matrix of intensities at each of the three wavelengths and is given as follows.

5. The estimated spectra are presented below.