| Category: |
Data Processing and Evaluation – Images |
| Author: |
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| Description: |
Script to compute a periodogram from the active image, using the Welch method (averaging pieces.)
Also does a rotational average of the sq. modulus, outputting the data to a .csv file and a Gatan line profile.
It writes the spatial frequency in the units 1/A.
I installed the script to a menu item; also runs from the script file. |
| Comments: |
Uses values stored as tags for repeated use. Defaults are set by the script. I edit these with the Tag editor. I understand the form of these tags changed in v. 1.6
This is a bug fix than handles the loops correctly. |
| Acknowledgements: |
Uses ideas from HanningFFT.s by Ruben Bjorge of NTNU
and especially P. D. Welch et al., "The Use of Fast Fourier Transform for the Estimation of Power Spectra: A Method Based on Time Averaging Over Short, Modified Periodograms", IEEE Transactions on Audio Electroacoustics, Volume AU-15 (June 1967), pages 70-73
Also uses ideas from the Gatan Scripting section of the DM User Manual |
| Script version: |
2.0 |
| DM/GMS version: |
1.8 |
| Script written as a function: |
Yes |
| Source: |
Show code |
| Download Source Code: |
 |
| Download Zip File: |
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