Using eis_auto_fit#

The IDL routine eis_auto_fit is available in the EIS part of the Solarsoft tree, and performs single Gaussian fitting to calibrated EIS data.

In order to use eis_auto_fit you must first calibrate your EIS data with eis_prep. You should then extract the data window that you are interested in with eis_getwindata(). E.g., for Fe XII 195:

IDL> wd=eis_getwindata(level1_filename,195.12)

You can then use eis_auto_fit as follows:

IDL> eis_auto_fit,wd,fit,refwvl=195.12

it is necessary to specify the reference wavelength in order to compute a velocity array from the measured centroid positions. The output 'fit' is an IDL structure with a number of tags including ones for intensity, line width, centroid and velocity, each of which has an associated 1-sigma error array.

If you do not want to use all of the wavelength window in the fit, you can use either the wvlpix= or pix_all= keywords. Please check the routine header for details on how to use these keywords.

eis_auto_fit uses the MPFIT procedures of C. Markwadt for fitting.