Re: Series expansion question
- To: mathgroup at smc.vnet.net
- Subject: [mg122705] Re: Series expansion question
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Mon, 7 Nov 2011 05:51:29 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
On 11/6/11 at 5:56 AM, recif at yahoo.com (Recif) wrote:
>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:
>However when I assign values to a and b:
>a = x0 + z
>b = y0 + z
>gts[a,b] gives me an error
How about:
In[2]:= gts[x_, y_] :=
Block[{a, b},
Normal[Series[g[a, b], {a, x0, 1}, {b, y0, 1}]] /. {a -> x, b
-> y}]
In[3]:= gts[x + x0, y + y0]
Out[3]= y*(x*Derivative[1, 1][g][x0, y0] +
Derivative[0, 1][g][x0, y0]) +
x*Derivative[1, 0][g][x0, y0] + g[x0, y0]