mjo-linear_algebra.tex: add the Moore-Penrose \pseudoinverse.

diff --git a/mjo-linear_algebra.tex b/mjo-linear_algebra.tex
index 02e1d12aba4d6383ee2b79f44eea272d96457329..aa0b05eaa640e74bc435aa85eab6c455c443a14c 100644 (file)
--- a/mjo-linear_algebra.tex
+++ b/mjo-linear_algebra.tex
@@ -37,6 +37,10 @@
 % specialized to real matrices.
 \newcommand*{\transpose}[1]{ #1^{T} }
 
+% The Moore-Penrose (or any other, I guess) pseudo-inverse of its
+% sole argument.
+\newcommand*{\pseudoinverse}[1]{ #1^{+} }
+
 % The trace of an operator.
 \newcommand*{\trace}[1]{ \operatorname{trace}\of{{#1}} }