spectrum
Description
Show the mean intensities for each frequency band in each region of interest (ROI) in each input. If an input has no ROI, the intensities of all the pixels in the input are used.
It's quite possible for the different inputs to be different images, to permit comparison.
Each region (or input) has a separate line in the resulting plot, labelled with the annotation for the ROI (or "inputN" for an input with no ROI). If ROIs in different inputs have the same annotation, they are labelled as "inN:annotation" where N is the input number.
Each pixel has its own variance, so the shown variance is the pooled variance of all the pixels in the region. This is calculated as the variance of the means, plus the mean of the variances. SpectrumSet handles this.
If a point has data with BAD DQ bits in a band, those pixels are ignored in that band. If there are no good points, the point is not plotted for that band.
A table of the values is also produced, and this output as CSV text. The table has one row per ROI or input, and the columns
- name - the name of the ROI or input
- mwavelength - the mean intensity for the given wavelength band
- swavelength - the population standard deviation of the mean intensity for the given wavelength band
- pwavelength - the number of pixels in the given wavelength band (usually the same as the number of pixels in the ROI, but may be fewer if the ROI has "bad" pixels in that band)
The last two columns are repeated for each wavelength band.
Connections
Inputs
| Index | Name | Type | Desc |
|---|---|---|---|
| 0 | 0 | img | a single line in the plot |
| 1 | 1 | img | a single line in the plot |
| 2 | 2 | img | a single line in the plot |
| 3 | 3 | img | a single line in the plot |
| 4 | 4 | img | a single line in the plot |
| 5 | 5 | img | a single line in the plot |
| 6 | 6 | img | a single line in the plot |
| 7 | 7 | img | a single line in the plot |
Outputs
| Index | Name | Type | Desc |
|---|---|---|---|
| 0 | data | data | a CSV output (use 'dump' or 'sink' to read it) |