Differences

This shows you the differences between two versions of the page.

--- tutorial:transformations [2014/01/03 15:45] – external edit 127.0.0.1
+++ user_guide:tutorials:transformations [2019/01/28 17:40] – ↷ Links adapted because of a move operation oroehrig
@@ Line 1: / Line 1: @@
 ===== Polytopes and Linear Maps =====
-polymake works with [[tutorial:coordinates|homogeneous coordinates]], which is why //projective// linear transformations are natural to apply to polytopes. Affine transformations are a special case.  By the way, a //transformation// is always bijective, by definition.
+polymake works with [[user_guide:tutorials:coordinates|homogeneous coordinates]], which is why //projective// linear transformations are natural to apply to polytopes. Affine transformations are a special case.  By the way, a //transformation// is always bijective, by definition.
 ==== Transformations ====
@@ Line 67: / Line 67: @@
 <code>
 polytope > $A=new Matrix<Rational>([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,0]]);
+</code>
-polytope > transform($c,$A);
+Using transform would not work in this case:
+<code>
+# polytope > transform($c,$A);
 polymake:  ERROR: matrix not invertible
 </code>
+The above error says that transform is not the proper function to deal with this situation as the linear map given by A is not invertible.
-The above error says that transform is not the proper function to deal with this situation as the linear map given by A is not invertible.  To produce the image the following command works:
+To produce the image the following command works:
 <code>