Re: Disappearing Function Definition
- To: mathgroup at smc.vnet.net
- Subject: [mg45030] Re: Disappearing Function Definition
- From: drbob at bigfoot.com (Bobby R. Treat)
- Date: Sat, 13 Dec 2003 06:06:28 -0500 (EST)
- References: <brcihd$2s4$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
The kernel seems to be crashing on the Integrate! A clue to that is
that the In/Out numbers are reset to 1 afterward.
f[x_,y_]:=x+y
g="Hello"
f[x,y]
Hello
x+y
Pick[x_, y_] = Sum[DiracDelta[y-t], {t, x}];
Integrate[f[x, y]*Pick[x, y], {y, 0, 100}]
?f
g
?Pick
Global`f
g
\!\(\*
RowBox[{\(Information::"notfound"\), \(\(:\)\(\ \)\), "\<\"Symbol \
\\!\\(\\\"Pick\\\"\\) not found.
\\!\\(\\*ButtonBox[\\\"More\[Ellipsis]\\\", \
ButtonStyle->\\\"RefGuideLinkText\\\", ButtonFrame->None, \
ButtonData:>\\\"General::notfound\\\"]\\)\"\>"}]\)
Bobby
"Scott Guthery" <sguthery at mobile-mind.com> wrote in message news:<brcihd$2s4$1 at smc.vnet.net>...
> Can anybody explain the following? Note that In[4] thinks for
> a while and then returns with no Out[4] but if you then take a
> look at f its definition has disappeared.
>
>
> In[1]:= f[x_, y_] = x + y
>
> Out[1]:= x+y
>
> In[2]:= f[x,y]
>
> Out[2]:= x+y
>
> In[3]:= Pick[x_, y_] = Sum[DiracDelta[y-t], {t, x}]
>
> Out[3]:= \!\(\[Sum]\+\(t = 1\)\%x DiracDelta[\(-t\) + y]\)
>
> In[4]:= Integrate[f[x, y]*Pick[x, y], {y, 0, 100}]
>
> *** Nothing returned here ***
>
> In[1]:= f[x,y]
>
> Out[1]= f[x,y]