calibrate using "file"
The calibrate command will attempt to fit the relationship between channel number and some specified calibration units.
The first line of the specified file contains a string specifying the name of the calibration units. The remaining lines each contain two numbers separated by space characters. The first number is the position of a peak in calibrated units and the second number it is relative intensity.
keV 121.78 28.4 344.28 26.6 411.12 2.23 778.9 13.0 964.13 14.3 1408.01 20.9
The calibration fit will be saved until the program exits or until cleared using the clear calibration command.