NAME

Ifeffit::Demeter::Data::Mu - methods for handling XAS mu(E) data

VERSION

This documentation refers to Ifeffit::Demeter version 0.0.1

SYNOPSIS

  my $data = Ifeffit::Demeter::Data ->
       new({group => 'data0',});
  $data -> set({is_xmu    => 1,
                file      => "fe.060.xmu",
                bkg_rbkg  => 1.4,
                bkg_spl2e => 1800,
                fft_kmax  => 3, # \ note that this gets
                fft_kmin  => 14,# / fixed automagically
                fft_rmax  => 4.3,
                label     => 'My copper data',
               });
  $data -> plot("r");

DESCRIPTION

This subclass of Ifeffit::Demeter::Data contains methods for dealing with mu(E) data.

METHODS

Data processing methods

normalize

This method normalizes the data and calculates the flattened, normalized spectrum.

  $data_object -> normalize;

autobk

This method computes the background spline using the Autobk algorithm and extracts chi(k) from the mu(E) data.

  $data_object -> autobk;

plotE

This method plots the data in energy using information from the Plot object.

  $data_object -> plotE;

This method is not typically called directly. Instead it is called as one of the options of the more generic plot method.

save_xmu

This method writes an output mu(E) file containing the background, pre- and post-edge lines, and first and second derivatives.

  $data_object -> save_xmu;

This method is not typically called directly. Instead it is called as one of the options of the more generic save method.

save_norm

This method writes an output mu(E) file containing the normalized data and background, flattened data and background, and the first and second derivatives of the normalized data.

  $data_object -> save_norm;

This method is not typically called directly. Instead it is called as one of the options of the more generic save method.

This method generates code for making an Ifeffit array containing a Heaviside step function centered at the edge energy and placed on the grid of the energy array associated with the object. The resulting array containing the step function will have the suffix step.

    $string = $self->step;

_plotE_command

This method generates a string containing the commands required to plot data in energy. It is called by the plotE method, which then disposes of the commands.

Utility methods

find_edge

This method determines the absorber and edge of mu(E) data by comparing the edge energy for these data to a table of edge energies of the elements.

   ($elem, $edge) = $self->find_edge($e0);

clamp

This method translates between numeric and descriptive values of clamping strengths.

e2k

This method converts between relative energy values and wavenumber.

k2e

This method converts between relative wavenumber and energy values.

BUGS AND LIMITATIONS

Cromer-Liberman normalization is not yet implemented.

There is currently no mechanism for importing an array into Ifeffit and associating an object with it.

Please report problems to Bruce Ravel (bravel AT anl DOT gov)

Patches are welcome.

AUTHOR

Bruce Ravel (bravel AT anl DOT gov)

http://cars9.uchicago.edu/~ravel/software/

LICENCE AND COPYRIGHT

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.