GUI Buttons

• mean - return the straight mean
• median - median clips at N*sigma (default N=3.0). Iteritively discards the maximum data point until either the maximum is less than N*sigma or there are only 3 points left. Returns the mean of the clipped data at a given data point. If there are 3 or less data points it returns the mean
• weighted - return the weighted mean (No warnings are given if 0 STDEVs are present -change to warn??)
• Med Min - Median clipping as above but discards both the minimum and the maximum data point until both are less than N*sigma or there are less than 4 data points remaining. Returns the mean of the clipped data.
• Minf - Median clipping as above but discards first the minimum and then the maximum data point until both are less than N*sigma or there are less than 4 data points remaining. Returns the mean of the clipped data.
• Maxf - Median clipping as above but discards first the maximum and then the minimum data point until both are less than N*sigma or there are less than 4 data points remaining. Returns the mean of the clipped data.

Additional parameters can be set-up prior to averaging the data

• Setup STDEV cut-offs: A cutoff can be set based on the STDEV. Both the DET and STDEV tags must be present to use this option. If this is an LWS fast scanning observation the STDEV at each data point is the goodness of fit of the ramp slope. This can be plotted as a function of time (if the ITK tag is present). Poorly fitted ramps show a larger goodness of fit and indicate undetected glitches etc. If the ITK tag is missing the STDEV is plotted as a function of wavelength.
  Setup Cut-offs Button: Click on this button and the `Detector selector for cut-off Fitting' widget will pop-up.
  • Clear All: Clears all fits to the STDEV data
  • Detector Buttons There is a button for each detector present in the AAR. Click on a detector button and a pull down menu will appear with
    • set cut-offs: Click on this button and the cut-off selector widget will pop-up with the STDEV plotted as a function of time (if the ITK tag is present) (FIX SO PLOT LABELLED??) or wavelength (if the ITK tag is missing). Use the left mouse button to select a cut-off position. Confirm this poition by clicking the right mouse or cancel the poition with a click of the left mouse button. Continue until you have selected enough cutoff points (plotted as green asterisks) to fit your data. You can chose to do either a 1st, 2nd or 3rd order polynomial fit or a spline fit. The spline fit has a pop-up tension bar to adjust the fit. At any stage you can either clear your selected cutoff positions, quit the fitting or keep the fit by clicking on exit. If you saved your fit the detector button will now be marked with an asterisk. Continue to set cut off values for the other detectors (you do not have to set values for all the detectors). When you have finished click on done to keep your cut-off values and cancel to quit the fitting procedure. Clear all allows you to clear all the detector cutoffs that you have set.
    • clear: Clears any cut-off fit you have stored for this detector data
  • Done: exit and keep the cut-off values that you have set
  • Quit: Quit the fitting process and do not keep any cut-off values
• use STDEV Cutoffs: Use the cut-offs that you have set for the detectors. You cannot use this option with average across detectors.
• Average across detectors: This will average the overlapping portions between detectors. It is best used after you have shifted the individual detector data so that they all line up! For example average the data for each detector, exit average, use shift or normalise to shift the detectors so that the overlap then go back into average and average across detectors using a binsize. When you use this option you cannot select any cut-off values.
• sigma - value used for median clipping
• Bin Size: The data is averaged at a given wavelength. The binsize is in the same units as the wavelength i.e x-data. This is usually microns(um).
  • lws: This is the default value for LWS GRATING observations
  • enter: enter a bin size. Click on the enter button and the default value of 1.e-5 appears in the "value' text widget. You can enter a new default value here.
• environment - move when it matches others???
  • linear
  • linear+errors
• Exit - Return to the main ISAP GUI and merge the averaged data with the remaining portion (if any) of the PRIME AAR.
• Quit - Return to the main ISAP GUI and do not keep the averaged data.