Added 'row'/'col' input to gtMathsRotationMatrixComp to avoid confusion....

Added 'row'/'col' input to gtMathsRotationMatrixComp to avoid confusion. Modified the caller functions accordingly.

git-svn-id: https://svn.code.sf.net/p/dct/code/trunk@543 4c865b51-4357-4376-afb4-474e03ccb993

zUtil_Maths/gtMathsRotationMatrixComp.m

-function rotmatcomp = gtMathsRotationMatrixComp(rotdir)
+function rotmatcomp = gtMathsRotationMatrixComp(rotdir, rc)
 % GTMATHSROTATIONMATRIXCOMP
-%     rotmatcomp = gtMathsRotationMatrixComp(rotdir)
+%     rotmatcomp = gtMathsRotationMatrixComp(rotdir, rc)
 %     ----------------------------------------------
 %
-%     Given an arbitrary rotation axis in 3D space, returns the three matrices
-%     in Rodrigues's formula. The matrices can be used to compose the rotation
-%     tensor. Considers right-handed rotation for a positive angle.
+%     Given an arbitrary rotation axis in 3D space, returns the three 
+%     matrices in Rodrigues's formula (see below). The matrices can be
+%     used to compose the rotation matrix for any angle. It considers 
+%     right-handed rotation for a positive angle.
 %
-%     To be used with ROW VECTORS, MULTIPLY FROM THE RIGHT side!
-%     Multiplication of column vectors from the left gives the wrong result!
+%     Output to be used with row or column vectors: 
+%        1. For ROW VECTORS:     rowvector_rotated = rowvector*Srot
+%        2. For COLUMN VECTORS:  colvector_rotated = Srot*colvector
+%     NOTE: Using the matrix on the wrong side gives the inverse result!
 %
-%     Rodrigues's rotation formula describes a linear combination of
+%     Rodrigues's rotation formula describes a linear combination of three
 %     matrices with only cos(om) and only sin(om) dependent terms:
 %       Srot = Sconst + Scos*cos(om) + Ssin*sin(om)
-%         Srot: rotation tensor for a row vector:
-%                 rowvector_rotated = rowvector*Srot
+%         Srot: 3x3 rotation matrix 
+%                 for row vectors:     rowvector_rotated = rowvector*Srot
+%                 for column vectors:  colvector_rotated = Srot*colvector
 %         om  : rotation angle
 %
+%     To get Srot from the components, use gtMathsRotationTensor.
+%
+%
 %     INPUT
 %       rotdir - rotation axis direction in LAB coordinates for right-handed
-%                rotation; unit vector (1,3)
+%                rotation; unit vector (1x3 for row, 3x1 for column vectors)
+%       rc     - 'row' for row vectors, 'col' for column vectors
 %
 %     OUTPUT
-%       rotmatcomp.const = matrix Sconst (3,3)
-%       rotmatcomp.cos   = matrix Scos   (3,3)
-%       rotmatcomp.sin   = matrix Ssin   (3,3)
+%       rotmatcomp.const = matrix Sconst (3x3)
+%       rotmatcomp.cos   = matrix Scos   (3x3)
+%       rotmatcomp.sin   = matrix Ssin   (3x3)
 
-    if ((size(rotdir,1) ~= 1) || (size(rotdir,2) ~= 3))
-        error('Input rotdir has to be a 1x3 row vector.')
-    end
+if strcmp(rc,'row') && (size(rotdir,1) == 1) && (size(rotdir,2) == 3)
 
     rotmatcomp.const = rotdir' * rotdir;
     rotmatcomp.cos   = eye(3) - rotmatcomp.const;
     rotmatcomp.sin   = [         0,  rotdir(3), -rotdir(2) ; ...
                         -rotdir(3),          0,  rotdir(1) ; ...
                          rotdir(2), -rotdir(1),          0 ];
+
                      
+elseif strcmp(rc,'col') && (size(rotdir,1) == 3) && (size(rotdir,2) == 1)
+   
+    rotmatcomp.const = rotdir * rotdir';
+    rotmatcomp.cos   = eye(3) - rotmatcomp.const;
+    rotmatcomp.sin   = [         0, -rotdir(3),  rotdir(2) ; ...
+                         rotdir(3),          0, -rotdir(1) ; ...
+                        -rotdir(2),  rotdir(1),          0 ];
+    
+else
+    error('Wrong input format. See function help.')
+end
+
+
 end % end of function