====== Displaying the motion-parameters of a subject ======

===== Motivation =====
While SPM writes out the motion parameters into a text file, sometimes only the files remain (e.g. after pruning the folders). For such cases, the motion parameters can be retrieved from the Analyze files and re-displayed using the [[showspmrparams]] function.

===== Requirements =====
This function reads motion parameters from the following files:
  * realigned (but **not resliced!**) Analyze/NIftI files
  * SPM's rp_*.txt files (which then does **NOT** contain the information of motion between runs!)

===== Usage =====
The usage is straight forward. Simply change into the folder where the run folders are located and execute the following command:

<code matlab showspmrparams_example.m>% only read from run folders with "attention" in their name
% and read raw files (which begin with a capital letter S)
[f, rpf] = showspmrparams([pwd '/*attention*'], struct('source', 'S*.hdr'));</code>

===== Output =====
Next to the figure handle (in this example variable name ''f''), the function also returns the motion parameters for further plotting or scripting commands such as ''max(rpf) - min(rpf)'' (which would give the peak-to-peak distance, a.k.a. as maximum motion in each of the six degrees of freedom).

The graphical output looks like this:

{{:showspmrparams_tworuns_fromfiles.png|showspmrparams output with two runs and 200 volumes each}}