====== vmr.ApplyTRF ======

===== Motivation =====
The main motivation for using this function is the ability to flexibly script spatial VMR transformation in Matlab.

===== Method reference ('vmr.Help('ApplyTRF')') =====
<file> VMR::ApplyTRF  - apply transformation to VMR
 
 FORMAT:       newvmr = vmr.ApplyTRF(trf [, opts])
 
 Input fields:
 
       trf         TRF object
       opts        struct with optional fields
        .asdouble  store output as double (default: false)
        .inverse   apply inverse transformation (default: false)
        .method    interpolation, see flexinterpn_method (default: 'linear')
 
 Output fields:
 
       newvmr      transformed VMR</file>

===== Usage examples =====
  * using a TRF that was created in BrainVoyager (and instead of the file selector in the first two lines, this can be scripted!): <code matlab vmr_applytrf_bvtrf.m>%load VMR and TRF
vmr = xff('*.vmr');
trf = xff('*.trf');

% apply transformation with cubic interpolation
trfvmr = vmr.ApplyTRF(trf, struct('method', 'cubic'));
trfvmr.SaveAs;

% clear objects
vmr.ClearObject;
trf.ClearObject;
trfvmr.ClearObject;</code>
  * using two VMRs, coregister them, then transform the first: <code matlab vmr_applytrf_coreg.m>% load two VMRs
vmr1 = xff(sourcevmr);
vmr2 = xff(targetvmr);

% run coregistration (requires SPM5 or SPM8 on the path!!)
% vmr2 is the target space (stationary), vmr1 the one to be resampled!
trf = vmrspmcoreg(vmr1, vmr2)

% resample vmr1 using sinc (lanczos3) interpolation
vmr1_in_vmr2_space = vmr1.ApplyTRF(trf, struct('method', 'lanczos3'));

% save TRF and VMR
[sourcepath, sourcefile] = fileparts(sourcevmr);
if isempty(sourcepath)
    sourcepath = '.';
end
[nullpath, targetfile] = fileparts(targetvmr);
trf.SaveAs(sprintf('%s/%s-TO-%s.trf', sourcepath, sourcefile, targetfile));
vmr1_in_vmr2_space.SaveAs(sprintf('%s/%s-TO-%s.vmr', sourcepath, sourcefile, targetfile));

% clear objects
clearxffobjects({vmr1, vmr2, trf, vmr1_in_vmr2_space});</code>