Data manipulation
EstraPy provides core data manipulation commands to prepare and reshape XAS datasets before analysis. This page covers three essential operations: cutting, rebinning, and smoothing.
Cut
The cut command restricts the dataset to a given range, discarding all values outside the specified bounds. It modifies the entire data table, removing the values outside the specified range. See Number and unit specification for the range syntax explanation.
cut <range>
The bounds may be specified in any valid unit. EstraPy automatically infers the domain over which to cut (real domain: eV, k, fourier domain: A). If the unit is not specified, the default domain is assumed to be the energy axis (E, eV).
Example
cut 5000eV 8000eV
This cuts the dataset to include only data between 5000eV and 8000eV.
Smooth
The smooth command applies LOWESS smoothing to a selected column in the dataset. This helps reduce noise while preserving trends in the signal.
smooth [column] [axis] [--options]
| Argument | Explanation |
|---|---|
[column] | Column to smooth. Default is a. |
[axis] | Axis to use as the x-coordinate for the smoothing. Default is E. |
--window / -w <value> | Width of the window (in number of points) to use for the LOWESS smoothing. |
Example
smooth a E --window 15
Smooths the a column over the energy axis using a 15-point LOWESS window.
Rebin
The rebin command redistributes and averages data across a new set of bins with specified interval or number of points. This is useful for uniform sampling or to match data resolution for comparative analysis. The command only averages the data, and does not create new datapoints. Bins that do not refer to any datapoints are discarded. The commands modifies the entire table in-place.
rebin <range> <interval>
rebin <range> --number <points>
You can specify the range explicitly with units, and either provide a fixed interval or specify the number of desired points.
| Argument | Explanation |
|---|---|
<range> | The range to rebin within. See Number and unit specification for the range syntax explanation. |
<interval> | The spacing between output points. If the interval unit is n (e.g. 15n), is equivalent to --number 15 |
--number / -n <value> | Number of output points to generate. Cannot be use with interval. |
Examples
rebin 5000eV 8000eV 0.5eV
Rebins the dataset between 5000 and 8000 eV with a spacing of 0.5 eV.