[FIX] coord for mrconvert

[rmukh]

Summary

Fixes # .

List of changes proposed in this PR (pull-request)

mrconvert in the newest version of MRtrix3 crashes if -coord is float

Acknowledgment

• [X ] (Mandatory) I acknowledge that this contribution will be available under the Apache 2 license.

[codecov]

Codecov Report

Merging #3369 (8bf5af2) into master (7080ef9) will decrease coverage by 0.26%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3369      +/-   ##
==========================================
- Coverage   65.11%   64.84%   -0.27%     
==========================================
  Files         307      307              
  Lines       40373    40364       -9     
  Branches     5326     5326              
==========================================
- Hits        26288    26174     -114     
- Misses      13014    13099      +85     
- Partials     1071     1091      +20     

Flag	Coverage Δ
unittests	64.84% <ø> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
nipype/interfaces/mrtrix3/utils.py	83.00% <ø> (ø)
nipype/interfaces/r.py	45.83% <0.00%> (-37.51%)	⬇️
nipype/interfaces/nipy/base.py	80.00% <0.00%> (-20.00%)	⬇️
nipype/testing/utils.py	70.90% <0.00%> (-18.19%)	⬇️
nipype/workflows/__init__.py	88.23% <0.00%> (-11.77%)	⬇️
nipype/interfaces/freesurfer/base.py	65.32% <0.00%> (-11.30%)	⬇️
nipype/info.py	78.12% <0.00%> (-9.38%)	⬇️
nipype/pkg_info.py	75.00% <0.00%> (-6.25%)	⬇️
nipype/interfaces/fsl/base.py	77.65% <0.00%> (-3.20%)	⬇️
nipype/pipeline/plugins/legacymultiproc.py	63.23% <0.00%> (-2.46%)	⬇️
... and 27 more

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[effigies]

If previous versions allowed floats, then this change could break workflows that were written for those versions. Do you know what the history is here?

[effigies]

@Lestropie Possibly you could shed some light here?

[Lestropie]

Proposed change is correct. First input to mrconvert -coord has always been an integer, as it selects an image axis. If a pipeline is attempting to pass a genuine floating-point number here, breaking it is IMO the best outcome.

In MRtrix3 C++ binaries, attempting to convert e.g. string "3.6" to an integer happens via operator >> on a std::istringstream, which simply terminates upon encountering the first incompatible character, and so would terminate at the dot point character and yield 3 in this case. Reason for the change in behaviour is that from 3.0_RC3 to 3.0.0 (specifically MRtrix3/mrtrix3#1794), an additional check is applied to ensure that the entire string is consumed in that conversion; so now attempting to convert string "3.6" to an integer will result in an Exception being thrown (and command execution failure if not caught). This successful conversion of substrings to numerical values was causing a number of stealthy bugs, so we now forbid it.

[effigies]

Sounds good. Thanks for the confirmation.