newbie question: plotting signum(x) doesn't work

Ashot,

Sorry for the bother. The problem with plot2d(signum(x), ...) is an
unintended side effect of my attempt to fix something else.

Here's a work around. Copy the following into a file, say tmp.lisp,
and then enter load("tmp.lisp"); at the input prompt.

(defun $signum (x) (|''MAKE-FUN| '%signum x))
(defun $erf (x) (|''MAKE-FUN| '%erf x))
(defun $round (x) (|''MAKE-FUN| '%round x))
(defun $truncate (x) (|''MAKE-FUN| '%truncate x))
(defun $plog (x) (|''MAKE-FUN| '%plog x))

Then plot2d should work for the functions signum, erf, etc.
A bug fix will be in the next Maxima release (December).

HTH

Robert Dodier

PS. To everyone else -- the above list was obtained via the following.
The symbols in the MAPCAR argument are dollarified versions of all
the symbols in the :maxima package which begin with "%" and have
simplification functions.

MAXIMA> (mapcar #'(lambda (s) (if (fboundp s) t `(nil ,s)))
'($INVERSE_JACOBI_SN $INVERSE_JACOBI_SC $INVERSE_JACOBI_SD $AIRY_BI
$INVERSE_JACOBI_NC $INVERSE_JACOBI_ND $INVERSE_JACOBI_NS $TANH
$ELLIPTIC_KC $AIRY_AI $TAN $ELLIPTIC_EC $SQRT $GAMMA $PLOG $SECH
$BESSEL_K $BESSEL_J $BESSEL_I $BESSEL_Y $SEC $ACOS $ACOT $SIN $ACSC
$DERIVATIVE $ASINH $MAYBE $PRODUCT $ACSCH $SUM $SIGNUM $TRUNCATE $COSH
$MATRIX $ATANH $COTH $ATAN $AIRY_DBI $AIRY_DAI $INTEGRATE $ASECH
$BINOMIAL $CHARFUN $ASEC $GENFACT $JACOBI_CS $ASIN $JACOBI_CN
$JACOBI_CD $JACOBI_AM $JACOBI_DS $JACOBI_DN $JACOBI_DC $ROUND
$JACOBI_NS $JACOBI_NC $JACOBI_ND $JACOBI_SN $JACOBI_SC $JACOBI_SD $ERF
$BUILDQ $ACOSH $LIMIT $LOG $ACOTH $COS $COT $CSC $SINH $MABS
$INVERSE_JACOBI_CN $INVERSE_JACOBI_CD $INVERSE_JACOBI_CS $CSCH
$INVERSE_JACOBI_DN $INVERSE_JACOBI_DC $INVERSE_JACOBI_DS $IS ))

=> (T T T T T T T T T T T T T T (NIL $PLOG) T T T T T T T T T T (NIL
$DERIVATIVE)
 T T (NIL $PRODUCT) T (NIL $SUM) (NIL $SIGNUM) (NIL $TRUNCATE) T (NIL $MATRIX)
 T T T T T T T T (NIL $CHARFUN) T T T T T T T T T T (NIL $ROUND) T T T T T T
 (NIL $ERF) (NIL $BUILDQ) T T T T T T T T (NIL $MABS) T T T T T T T T)