// This function scales the dimensions of a layer containing an image plot so that 
// the aspect ratio of the layer matches the aspect ratio of the matrix containting
// the data.
void ly_scale_image_plot()
{
	// Declare active layer as graph layer and check validity
	GraphLayer gly = Project.ActiveLayer();
	if( !gly )
	{
		out_str( "Active layer is not a graph layer!\n" );
		return;
	}

	// Loop thru all style holders in layer and check if a matrix image is present
	StyleHolder sh;
	bool bFound = false;
	foreach( sh in gly.StyleHolders )
	{
		if( IDM_PLOT_MATRIX_IMAGE == sh.GetPlotId() ) bFound = true;
	}
	if( !bFound )
	{
		out_str( "Layer does not contain a matrix image plot!\n" );
		return;
	}

	// Loop over all data plots in layer and find the matrix
	bFound = false;
	DataPlot dp;
	string strMatName;
	foreach( dp in gly.DataPlots )
	{
		strMatName = dp.GetDatasetName();
		// Try declaring a Matrix object and check validity
		MatrixLayer matLy( strMatName );
		if( matLy )
		{
			bFound = true;
			break;
		}
	}
	if( !bFound )
	{
		out_str( "No Matrix data was found in layer!\n" );
		return;
	}

	// Found the matrix object - get its dimensions
	int iNumRows, iNumCols;
	MatrixLayer matLy( strMatName );
	iNumRows = matLy.GetNumRows();
	iNumCols = matLy.GetNumCols();
	if( ( iNumRows < 2 ) || (iNumCols < 2 ) )
	{
		out_str( "Too few rows/cols in matrix!\n");
		return;
	}

	// Compute aspect ratio based on matrix dimension
	double dMatAspectRatio = 1. * iNumCols / iNumRows;

	// Check unit type of layer size - if not in inches, switch to inches temporarily
	int iLyUnitType = gly.Dimension.Units.nVal;
		// NOTE: You can directly access sub-properties of the layer such a units, 
		// which is part of Dimension property of the layer, with statements such 
		// as above. To see what properties are available, one can save a theme file
		// from a graph and look a the contents of the theme file.		
	bool bSwitchedUnits = false;
	// If units is not in inches, switch to inches
	if( 1 != iLyUnitType )
	{
		gly.Dimension.Units.nVal = 1;
		bSwitchedUnits = true;
	}

	// Now get the layer dimension properties into a tree
	Tree trLyDim;
	trLyDim = gly.Dimension;
		// NOTE: It is not necessary to copy the layer properties into a tree. 
		// One can work directly with the layer as in earlier code  where layer
		// dimension units were changed. This just shows that a tree could be used
		// as well.
		
	// Compute layer aspect ratio using layer dimensions
	double dLyAspectRatio = trLyDim.Width.dVal / trLyDim.Height.dVal;

	// Compare the matrix and layer aspect ratios
	double dVariance = abs( dMatAspectRatio - dLyAspectRatio ) / dMatAspectRatio;
	if( dVariance < 0.001 )
	{
		out_str( "Layer aspect ratio is same as matrix aspect ratio!\n" );
		return;
	}
	
	// Matrix and layer have different aspect ratios - so need to scale layer
	if( iNumCols > iNumRows )
		trLyDim.Height.dVal = trLyDim.Width.dVal / dMatAspectRatio;
	else
		trLyDim.Width.dVal = trLyDim.Height.dVal * dMatAspectRatio;

	// Set the tree back to apply the dimension change to the layer
	gly.Dimension = trLyDim;

	// If layer dimension units were switched, then switch back to original settings
	if( bSwitchedUnits )
		gly.Dimension.Units.nVal = iLyUnitType;
}