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Dear mrTrix community,<br>
<br>
I am currently running mrTrix 0.2.10 (mrtrix-0.2.10_2012-02-10) on
Linux and repeatedly encounter the error message:<br>
<br>
<tt><b>disp_profile: unexpected number of SH coefficients - assuming
response function</b></tt><br>
<br>
when I run the following command to plot the estimated single fiber
response function:<br>
<br>
<tt><b>disp_profile -response sf_response.txt</b></tt><br>
<br>
I have followed the documentation, specifically "Data
pre-processing" section, where it describes how to generate a
single-fiber mask, and call <b><tt>estimate_response</tt></b> to
determine the SH coefficients for the single fiber. I edited a
custom single-fiber mask, based on FA levels, and ensured that all
voxels in the mask were in white matter regions, and not be voxels
of erroneous FA values (e.g. FA > 1). <br>
<br>
Examples from two of my <tt><b>sf_response.txt</b></tt> files are:<br>
<br>
<tt>1862.36 -570.495 84.5122 -8.29821 0.629007</tt><br>
<br>
<tt>1296.21 -909.403 383.255 -116.241 28.1946</tt><br>
<br>
These values seem consistent with what is described in the
documentation. So, I find it very odd that I am receiving the above
error message. Furthermore, even though the error appears, the
actual SH profile displayed changes (i.e. it doesn't seem to assume
and then load a default response function as the error states).<br>
<br>
Can anyone explain what is causing the <tt><b>disp_profile</b></tt>
error above? May be the outputting of the error message is the
error itself? Can anyone check <tt><b>disp_profile -response</b></tt>
using the values I have listed above. What are your outcomes?<br>
<br>
Thank-you researchers!<br>
Bryce<br>
<br>
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