PCA |. PCA demo 1
PCA Tutorial 2
- Load cube
- Tools / import / i/o / import from file
- Select demo-images / date-cubes / Enk / 128-96-100.raw.
- If a .rpl file is there, the parameters in the import window do not
need to be initialized.
- See cube image window - appears black. Slide the slider - see different
- Make plot of spectra with entire cube:
- Select / rectangle - select all. (see yellow rectangle in cube window).
- Data Cube / plot / of spect w/in rectangle
- Select peaks as separate layers
- data cube / slider / layers
- Select 7 layers, adjust sliders to enclose peaks.
- Make new cube with summed layers. 'cube / from layers. Note that this
cube has only 7 slices, rather than 101. However none of the 'counts'
are lost - but summed. Note that the cube as read in uses 2 bytes, but
that 'info / size and limits' shows that none of the pixels is over
1 byte. A new cube taking half of the memory could be made using ' cube
/ clip to byte', without loosing any data.
- Do principal component analysis of the summed
cube: PCA / 1 Eigenvalues
Note - a blank cube image (a mean centered copy of the original cube) is
made. It can be used in place of the original, or closed. To see slices, make
a slider: 'slider / view slice'.
- Show all the score images separately:
- 'image / slices to windows', take default (0 6) of all images.
- See 7 images being made.
- shift / resize.
- Click on score image 6, 5, ... 0. Temporarily reduce size of large
background window. Tile.
I didn't clean up the background before taking this last screen snapshot.
- Scatter diagrams, color overlays can be made with these score images.