gradef problem, was pw.mac problem



Maybe I am mistaken, someone please show me my error in thinking.

Rich


From: Richard Hennessy 
Sent: Thursday, July 11, 2013 3:16 PM
To: Barton Willis ; Rupert Swarbrick ; maxima at math.utexas.edu 
Subject: Re: [Maxima] gradef problem, was pw.mac problem

We have,

gradef(pwdelta(x), diff_pwdelta(1,x))$
gradef(diff_pwdelta(n,x), 'und, diff_pwdelta(n+1,x))$

<snip>

diff(pwdelta(s*x-v),x,4);   // problem below
-> diff_pwdelta(4,s*x-v)*s^4

This last line should be
diff(pwdelta(s*x - v), x, 4);
-> diff_pwdelta(4, s*x-v)
by definition of diff_pwdelta().

I don?t know a workaround for this one.

Rich