You are probably trying to do at(x^2,x=4)
or subst(4,x,x^2)
or x^2, x=4
atvalue is an entirely different concept, used for defining a function or
derivative at a point.
Please read the documentation. Try
atvalue('diff(f(x),x),x=0, c);
diff(f(x),x);
at(diff(f(x),x),x=0);
_____
From: maxima-bounces at math.utexas.edu [mailto:maxima-bounces at math.utexas.edu]
On Behalf Of J. Simons
Sent: Sunday, October 21, 2007 1:05 PM
To: maxima at math.utexas.edu
Subject: at
L.S.,
What goes wrong here :
(%i2) atvalue(x^2,x=4);
Maxima encountered a Lisp error: Error in MACSYMA-TOP-LEVEL [or a callee]:
MACSYMA-TOP-LEVEL [or a callee] requires more than two
arguments.Automatically continuing.To reenable the Lisp debugger set
*debugger-hook* to nil.
and here
(%i4) atvalue(x^2+y^3,[x=1,y=2]);
Maxima encountered a Lisp error:
Error in MACSYMA-TOP-LEVEL [or a callee]: MACSYMA-TOP-LEVEL [or a callee]
requires more than two arguments.
Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.
or what did I wrong ?
I don't understand the error_comment
Thanking you in advance for you help.
Best regards,
Jos? Simons