Re: Series expansion question
- To: mathgroup at smc.vnet.net
- Subject: [mg122717] Re: Series expansion question
- From: Alexei Boulbitch <Alexei.Boulbitch at iee.lu>
- Date: Mon, 7 Nov 2011 05:53:38 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
Hi, Recif,
This:
Clear[gts];
gts[x_, y_] := Normal[Series[g[x, y], {x, x0, 1}, {y, y0, 1}]];
gts[x, y] /. {x -> x0 + z, y -> y0 + z}
may help. Try. Have fun.
I defined a function:
gts[x_, y_] := Normal[Series[g[x, y], {x, x0, 1}, {y, y0, 1}]]
and when I use it with 'a' and 'b' undefined, I get the value I expect:
gts[a, b]
g[x0,y0] + (a-x0) g^(1,0)[x0,y0] + (b-y0) g^(0,1)[x0,y0] ...
However when I assign values to a and b:
a = x0 + z
b = y0 + z
gts[a,b]
gives me an error:
General::ivar: "x0+z is not a valid variable"
etc.
I would appreciate any help to fix this.
Thanks.
Recif
Alexei BOULBITCH, Dr., habil.
IEE S.A.
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