Re:Computing dynamic functions
- To: mathgroup@smc.vnet.net
- Subject: [mg11598] Re:Computing dynamic functions
- From: Allan Hayes <hay@haystack.demon.co.uk>
- Date: Tue, 17 Mar 1998 10:43:30 -0500
In response to my earlier posting
Gabriel Alvarez writes
> What I do not know how to do is to type
>
> ``Something with h's, x_, := ... and Expand[(1+x)^2]''
>
> and get
>
> h[x_]:= h[x] = 1 + 2 x + x^2
The following does this
In[1]:=
remember[ h_,x_,g_]:= (h[x_]:=h[x] = g)
RuleDelayed::"rhs":
"Pattern \!\(x_\) appears on the right-hand side of rule \
\!\(\(remember[\(h_, x_, g_\)]\) \\[RuleDelayed] \(\(h[x_]\) :=
\(\(h[x]\) = \ g\)\)\)."
We can ignore the message.
In[2]:=
remember[h,x,Expand[(1+x)^2]]
In[3]:=
?h
"Global`h"
h[x_] := h[x] = 1 + 2*x + x^2
Some use of holding attributes would change the behaviour --
Allan Hayes
Training and Consulting
Leicester, UK
hay@haystack.demon.co.uk
http://www.haystack.demon.co.uk
voice: +44 (0)116 271 4198
fax: +44 (0)116 271 8642