ParameterObject::WriteParameterFiles does not write the first map!

[N-Dekker]

It appears that ParameterObject::WriteParameterFiles skips the first map from the specified parameterMapVector:

elastix/Core/Main/elxParameterObject.cxx

Lines 379 to 401 in 81324cf

	ParameterObject::WriteParameterFiles(const ParameterMapVectorType & parameterMapVector,
	const ParameterFileNameVectorType & parameterFileNameVector)
	{
	if (parameterMapVector.size() != parameterFileNameVector.size())
	{
	itkGenericExceptionMacro(<< "Error writing to disk: The number of parameter maps (" << parameterMapVector.size()
	<< ") does not match the number of provided filenames (" << parameterFileNameVector.size()
	<< ").");
	}
	// Add initial transform parameter file names. Do not touch the first one,
	// since it may have one already
	for (unsigned int i = 1; i < parameterMapVector.size(); ++i)
	{
	ParameterMapType parameterMap = parameterMapVector[i];
	if (parameterMap.find("TransformParameters") != parameterMap.end())
	{
	parameterMap["InitialTransformParameterFileName"][0] = parameterFileNameVector[i - 1];
	}
	Self::WriteParameterFile(parameterMap, parameterFileNameVector[i]);
	}
	}

The bug appears introduced with pull request #50 commit 9ba1683 "ENH: Add convenience methods for writing parameter files", merged on March 20, 2018, when the member function became as follows:

elastix/Core/Main/elxParameterObject.cxx

Lines 256 to 280 in 9ba1683

	::WriteParameterFile( const ParameterMapVectorType & parameterMapVector, const ParameterFileNameVectorType & parameterFileNameVector )
	{
	if( parameterMapVector.size() != parameterFileNameVector.size() )
	{
	itkExceptionMacro(
	<< "Error writing to disk: The number of parameter maps ("
	<< parameterMapVector.size() << ")"
	<< " does not match the number of provided filenames ("
	<< parameterFileNameVector.size()
	<< ")." );
	}
	// Add initial transform parameter file names. Do not touch the first one,
	// since it may have one already
	for( unsigned int i = 1; i < parameterMapVector.size(); ++i )
	{
	ParameterMapType parameterMap = parameterMapVector[ i ];
	if( parameterMap.find( "TransformParameters" ) != parameterMap.end() )
	{
	parameterMap[ "InitialTransformParameterFileName" ][ 0 ] = parameterFileNameVector[ i - 1 ];
	}
	this->WriteParameterFile( parameterMap, parameterFileNameVector[ i ] );
	}
	}

FYI @kaspermarstal

[dzenanz]

That probably means that no one has been using that method. And whoever tried to use it, directly or indirectly, gave up on using it because it does not work. The solution is to make it work appropriately 😄

[thewtex]

I also encountered this issue:

https://github.com/InsightSoftwareConsortium/ITKElastix/blob/29ce6866414070136bb5bc2f70129eafcdde7040/wasm/write-parameter-files.cxx#L74-L76

[N-Dekker]

@dzenanz @thewtex Please check:

• BUG: ParameterObject::WriteParameterFiles should write all maps #967

[N-Dekker]

I also encountered this issue:
https://github.com/InsightSoftwareConsortium/ITKElastix/blob/29ce6866414070136bb5bc2f70129eafcdde7040/wasm/write-parameter-files.cxx#L74-L76

@thewtex Thanks Matt! Please remember that these two lines should be removed, once ITKElastix has been updated to include elastix PR #967 (commit a57470b):

// The initial is not written by WriteParameterFiles
ITK_WASM_CATCH_EXCEPTION(pipeline, elastix::ParameterObject::WriteParameterFile(parameterMaps[0], parameterFiles[0]));