On Fri, Dec 8, 2017 at 3:00 AM, woschangqiang@126.com
wrote:
Hello, dear everyone. I downloaded a XAFS data about mettalic Ru from the website of *ixs.iit.edu http://ixs.iit.edu*. There are 4 groups of information in the data, and each ranges between ~67800 with ~63000 in energy. So how to import the data to Athena, and how this kind of data was produced? Does anyone come across this situation? Thanks for your time and help in advance.
This data file is a particularly nasty form of data from the Lytle database. Each line of data contains consecutive pairs of AngleSteps Mu To convert the angle steps to energy, you need to know how many steps there are in a degree and the lattice constant of the mono crystal used. Neither of these are in the file. I happen to have a good guess that these numbers should be 8000 steps per degree, and 1.92017 Angstroms. Still the data are a pain to deal with. They can be read with Ifeffit too, but with Larch it goes like this: ru = read_ascii('ru.001.txt') # flatten array data to [step, mu, step, mu,...] dat = ru.data.transpose().flatten() # take every 2nd value as angle or xmu asteps = dat[0::2] xmu = dat[1::2] step2rad = (pi/180)/ 8000 # radians per step hc = 12398.417 # eV Ang dspace = 1.92017 # Ang energy = hc/(2*dspace)/sin(asteps * step2rad) label = 'energy xmu angle_steps' header = ['data converted from Lytle database file: %s' % ru.filename, 'using dspace=1.92017, steps-per-degree=8000'] write_ascii('ru.001.xmu', energy, xmu, asteps, header=header, label=label) Resulting converted file attached. --Matt