Procedures <Prev Next>

Simulating a Spectrum - the Plot Menu

Once a data file has been created or loaded (File, Open or or simply drag and drop a .pgo file onto the main window) simply press the red simulate button if a simulation does not appear automatically. To change the molecular parameters use the Constants Window. The plot menu entries, many of which are also available as toolbar buttons, can be used to adjust the appearance of the plot.  The Offset, rotational temperature (T),  and the Gaussian (Gau) and Lorentzian (Lor) contributions to the linewidth can also be changed using the boxes in the main window.

Note: To change the plot range, the Plot Selection () button is more useful than Magnify Plot ().

The items below are available as buttons on the toolbar or from the plot menu:

Left Shift plot range to left
Right Shift plot range to right
Compress Compress plot range
Expand Expand plot range
Plot Selection Click and drag the mouse over part of the spectrum and then press this button to change the plot range to the selected range. This only changes the horizontal range; if you want to look at part of the vertical range use the Magnify Plot .
All Expand plot range to include all simulated lines and overlayed spectra. This button is particularly useful if you have "lost" your spectrum.
Simulate Simulate spectrum
Next Plotstyle Cycle through available styles of plot
Show Parts Toggle display of individual spectra making up the overall spectrum
Show Sum Toggle display of sum of individual spectra
Fortrat, Show Toggle display of a Fortrat Diagram

Fortrat, Upper
Select upper or lower state quantum number as vertical axis in Fortrat diagram. It is also possible to adjust the quantum number used; the default is J, but others can be specified by adjusting FortatQno in Simulation

Units Select units for horizontal axis - Possibilities are cm-1, MHz, Kelvin, eV, velocity (in units of cm-1/2), nm in vacuum and nm in air.
Plot Options,
Styles...
This enables the colour, the width of the lines and the line style of spectra to be changed.  To alter one of these settings, select the relevant tick box, click "Apply", alter as required, and click "OK".  The changes will be effected on resimulating the spectrum.  Selecting "Default" restores spectra to solid, 0.0 Width lines.  (Colours of spectral lines are best changed in the constants window.)
Plot Options,
Font
Select font for plots.
Plot Options,
Variable Char Size
Select (default) for character size on printout, clipboard and export to reflect on screen proportions. If not selected he character size remains fixed.
Plot Options,
Limit Line Segments
Select (default) to limit number of segments on a plotted curve. It can be helpful to unselect this option if you intend to edit exported plots. The only drawback is that the resulting plots can be too complicated for some programs to handle.
Magnify Plot Click and drag with the mouse to select a region to zoom into with this button. In contrast to Plot Selection this changes both the vertical and horizontal scale.
Shrink plot Shrink plot
Reset Zoom Reset plot zoom to fill window