There are several mnemonics to remember the definition of the standard vector product in 3D. One of them works as follows (picture from learning-freiburg.de):
Obviously I am only interested in the structure of the left hand side. Now I was trying to typeset some examples of how this works for my students. I am using PSTricks and its psmatrix definition to do so. I get the following result (code below):
Clearly I fail to make it look pretty: The numbers are not aligned, the lines are all of different lengths (and colours are still missing). The reason for the wrong alignment is the minus signs. Without the minus signs the code works well, but of course students need to see how to deal with negative numbers when applying this technique.
My question thus is: How do I get proper alignment for numbers and lines in the presence of minus signs?
MWE
$\psmatrix[colsep=1cm,rowsep=.6ex] 1 & -4\\ -2 & 5\\ 3 & 6\\ 1 & -4\\ -2 & 5\\ 3 & 6 \endpsmatrix$ \psset{linewidth=.5\pslinewidth} \ncline[nodesep=-2em]{-}{1,1}{1,2}% strike through \ncline[nodesep=-2em]{-}{6,1}{6,2}% strike through \psset{nodesep=2pt}% three lines: \ncline{2,1}{3,2} \ncline{3,1}{4,2} \ncline{4,1}{5,2}% three more: \ncline{3,1}{2,2} \ncline{4,1}{3,2} \ncline{5,1}{4,2} I am somewhat flexible about solutions, it does not have to be all that similar to my attempt as long as we stay with PSTricks.
