Load spectral data from files in common EPR data formats.

eprload(FileName)
y = eprload(FileName)
[x,y] = eprload(FileName)
[x,y,Params] = eprload(FileName)
[x,y,Params,FileN] = eprload(FileName)
eprload
... = eprload
... = eprload(FileName,Scaling)

This function loads real or complex spectral data from files in common data formats of EPR spectrometers.

FileName is the filename to be loaded. If FileName is just a file name without a directory ('mydata.DSC'), eprload looks for it in Matlab's current directory. FileName can also include the full path to the file (C:\mydata\sample5\mydata.DSC'). If FileName is a directory, a file selection dialog box is displayed. If no FileName is given, the current directory is used as default.

x contains the x axis data (the magnetic field, time, frequency axis), y contains the spectral data, Params is a structure containing the entries from the associated parameter file (if it exists), and FileN is the name of the loaded file including the full path. If no output parameter is given, the loaded data are plotted.

If the spectrum is two-dimensional, then x contains both axes. x{1} is the first axis, and x{2} is the second axis.

All fields in Params are converted to numbers if possible. E.g., Params.XPTS='1024' is converted to Params.XPTS=1024. In addition, 'True' is converted to 1, and 'False' is converted to 0.

Formats are identified by the extension of the file name specified in FileName, which can be either the data file or the parameter file extension. If no extension is given, eprload tried several extensions. The following commercial formats are supported:

In addition, several older academic file formats are supported:

Depending on the nature of the data, a real or complex 1D, 2D or 3D array is returned in y.

Note that BES³T files stored in ASCII format cannot be read by eprload. In this case and for any other plain ASCII formats use MATLAB's textread function.

Scaling is a character array of one-letter codes that instructs eprload to scale the spectral data. The codes are:

• 'n': divide by the number of scans
• 'G': divide by the receiver gain
• 'P': divide by the square root of the microwave power (in milliwatts)
• 'T': multiply by the temperature (in kelvin)
• 'c': divide by the conversion/sampling time (in milliseconds)

For example, 'nGP' would scale the spectrum by the number of scans, the receiver gain, and the square root of the microwave power.

If Scaling is omitted, no scaling is performed. Currently, Scaling is only supported for Bruker par/spc files.

To load and display a one-dimensional CW EPR spectrum stored in BES³T format in the files myspec.DTA and myspec.DSC, type

[B,spec,pars] = eprload('myspec.DTA');
plot(B,spec);

To load and display a two-dimensional data set stored in BES³T format in the files myspec2d.DTA and myspec2d.DSC, use

[x,data] = eprload('myspec2d.DTA');
axis1 = x{1};     % first axis, e.g. magnetic field
axis2 = x{2};     % second axis, e.g. time or temperature
plot(axis1,data);

If you want to display the data only without retrieving the data, use

eprload('myspec.DTA');

eprsave