psql: add, postgresql configuration file

[config/dotfiles.git] / maxima / maxima-init.mac

diff --git a/maxima/maxima-init.mac b/maxima/maxima-init.mac
index 586cb32db238135fe1f001cd9b1fefd282fb50f4..1dedac1ba79932fc63ab1222536bf25db42be6a6 100644 (file)
--- a/maxima/maxima-init.mac
+++ b/maxima/maxima-init.mac
@@ -1,7 +1,15 @@
 /*
- * Maxima (computer algebra system) configuration file, maxima part.
+ * Maxima (computer algebra system) configuration file, Maxima part.
  *
- * Also have a look at maxima/maxima-init.mac.
+ * Also have a look at maxima/maxima-init.lisp.
+ *
+ * Notes:
+ *
+ * Solve Ax = b, thanks to Florian.
+ *
+ * A : matrix([1,2,0],[0,2,3],[0,0,4])$
+ * b : matrix([1],[3],[5])$
+ * linsolve_by_lu(A,b);
  */
 
 /*
@@ -30,7 +38,7 @@ norm(x) := sqrt(transpose(x) . x);
 /* Maxima's mat_norm() can't calculate the 2-norm. Thanks to Wolfgang Lindner
  * (http://www.ma.utexas.edu/pipermail/maxima/2007/006300.html) for an
  * improved version. */
-mat_norm2(x) := sqrt(lmax(eigenvalues(transpose(conjugate(x)).x)[1]));
+mat_norm2(x) := sqrt(lmax(eigenvalues(transpose(conjugate(x)) . x)[1]));
 
 /* Shortcut to perform lu factorization. */
 lu(x) := block(x : lu_factor(x), get_lu_factors(x));