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Residuals Window

This window is used to plot the observed - calculated values from a fit (or related quantities). Bring this up with View, Residuals if required.

The status bar displays the x, y co-ordinates of the mouse and, if the mouse is over an experimental point, the source of the data point. Note that you can often go directly to the source of the data by right clicking on a given point and selecting "Edit Point" - see below for other options. This requires the Slave Editor to be set up.Note that the average error displayed at the top is slightly different to the value given in fits - it is simply [Σ[(obsi-calci)/wi]2/nobs]½, and does not take account of the number of parameters floated. (This allows a value to be calculated without doing a fit.)
Reload observations and recalculate residuals (equivalent to doing a fit with no parameters floated).
Select the Y axis of the plot. Possible choices are:
  • Weighted Obs-Calc
  • Unweighted Obs-Calc
  • Weighted (Obs-Calc)/Obs = Relative weighted error
  • Unweighted (Obs-Calc)/Obs = Relative unweighted error
  • Observed
  • Calculated
  • Observed and Calculated
  • Weight
  • Calc/Obs
Some of these quantities are not residuals, but can be useful for indicating the data included in the fit. The ratio plots can be particularly useful when fitting intensities.

Take log (to base 10) of preceeding axis.
Select the X axis of the plot. Possible choices are:
  • Observation Number
  • Frequency
  • State Energy (Use the "Upper" check box to select the lower or upper state)
  • Calculated value
  • Observed Value
  • Weight
  • Population
  • J
  • N
  • F
  • A: Ω for linear molecules, |K| for symmetric tops, Ka for asymmetric tops
  • B: F1, F2...for linear molecules, Kl for symmetric tops, Kc for asymmetric tops
  • F1 Hyperfine quantum numbers (if appropriate)
  • F2
  • ...
  • F9
Check to use upper (rather than lower) state quantum numbers or state energy.
Plot data with zero weight (which would otherwise not be plotted).

If the x axis style is Observation Number, and the observations span more than one file, show the file boundaries and names on the plot.
Zoom into region selected with mouse.
Zoom plot out.
Reset plot to fill window.

PopupMenu Items

To bring up this menu right click on the plot. The first two items are only available if a specific point is clicked on.

Edit Point Open point under cursor in text editor if possible.
Show Transition Shift main plot to show transition that the indicated point derives from.
Copy to clipboard Use Paste Special to paste picture or underlying data (if available) in the target application
Print... Show print preview and allow print of plot
Export to file... Export plot to external file
Font... Choose font for graph text
Variable Char Size Character size on printer and clipboard depends on window size
Limit Line Segments Limit number of segments on a plotted curve. Leave this checked unless you have problems with the graph when printed or exported.