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This window is used to display the results of line position, line intensity, energy level or contour fits and will also display details of calculations if the PrintLevel is positive. For line position and intensity fits, a line list giving details of each fitted rotational line, with an observed and calculated frequency or intensity and obs-calc for each line, is also given. For a graph of the residuals, see the Residuals Window. Note that the information displayed applies to one fit cycle; as a non-linear fitting process is used expect to fit several times until convergence is obtained. Click on an item in the picture below for more information:
Observations |
nobs = The number of
lines fitted or the number of experimental points for a
contour fit |
Parameters |
npar = The number of parameters
floated |
Initial Average Error |
This is [Σ[(obsi-calci)/wi]2/(nobs-npar)]½
with the calculated values, calci, obtained using
the parameters at their initial values. wi
are the estimated (relative) standard deviations of the
observations. |
Predicted New Error | This is [Σ[(obsi-calci)/wi]2/(nobs-npar)]½
with the calculated values, calci, obtained from
the non-linear least squares fit. They are typically close
to the values that would be obtained from the new
parameters, but are only exact if the calculated values are
linear (or nearly linear) in the parameters. This is should
be the case near to convergence, but often not when starting
the fitting process. Fit again to find the true new error. |
Old |
The parameter value at the
start of the fit. |
New |
The parameter value after the
fit cycle. |
Std Dev |
The estimated standard
deviation of the parameter, based on the quality of the fit. |
Sens |
Watson's sensitivity
parameter (J. K. G. Watson, J. Mol. Spectrosc. 66, 500 (1977)) for the
parameter. This is the change in the parameter that would
make the average error of the fit increase by a factor of
0.1/npar,
and provides a useful guide as to how many figures should be
quoted for the parameter to ensure that the calculation can
be reproduced. Where parameter correlation is high, this can
be many more figures than suggested by the standard
deviation of the parameter. See also R. J. Le Roy, J. Mol.
Spectrosc. 191, 223 (1998) for discussion of this
issue, and alternative approaches. |
Summary |
The new parameter, with the
one standard deviation in units of the last figure in
brackets. The sensitivity is used to determine how many
figures are displayed for the standard deviation. |
Correlation Matrix | The correlation between the
parameters. |
Do fit of indicated type. For
fits other than a Contour fit, the experimental information
is taken from the file set at the top of the window.
Alternatively, you can take the information from the
clipboard by right clicking on the fit button. (This works
well if you prefer to use Excel or another spreadsheet
program to manage the experimental line list; before each
fit select the required area of the spreadsheet and copy it
to the clipboard.)
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Step constants back one fit cycle for each press | |||||||||||||||||
Step constants forward one fit cycle | |||||||||||||||||
Click to browse for
experimental file name |
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Edit given file; this button
will normally start the Slave
Editor |
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Clear log window | |||||||||||||||||
Copy log to clipboard. | |||||||||||||||||
Save log to file. |