Reflectance measurements from hawkmoth wings and natural backgrounds were taken with an Ocean Optics USB2000 + spectrometer (Dunedin, FL, USA), with the probe held at a 45° angle, coupled to either a PX-2 pulsed xenon lamp or a stabilized deuterium light source (SLS204, ThorLabs, ...
Although the principal components do not have a direct physical correspondence, they reflect the variable inputs, consisting of the main fluorescence bands, as identified in the spectra. Cluster analysis is also an unsupervised classification method. It aims to arrange the dataset into clusters based...