Re: Evaluate[expr]
- To: mathgroup at smc.vnet.net
- Subject: [mg123448] Re: Evaluate[expr]
- From: Sebastian Hofer <sebhofer at gmail.com>
- Date: Thu, 8 Dec 2011 05:21:13 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <jbni7r$48k$1@smc.vnet.net>
- Reply-to: comp.soft-sys.math.mathematica at googlegroups.com
As you can read in the manual: "Table effectively uses Block to localize values or variables."
If we try Block then we will find
In[41]:= Block[{x = 1}, {{x}, f[x], D[f[x], x]}]
During evaluation of In[41]:= General::ivar: 1 is not a valid variable. >>
Out[41]= {{1}, -1, \!\(
\*SubscriptBox[\(\[PartialD]\), \(1\)]\((\(-1\))\)\)},
which is essentially the same error message as for your original example. I think the produced output says it all: The symbol x is set to one and is thus not a valid variable for D[f[x], x] anymore.
In[42]:= x = 1; D[f[x], x]
will give the same.