Change of variables in integration
- To: mathgroup at smc.vnet.net
- Subject: [mg28266] Change of variables in integration
- From: "Loren Dill" <lorendill at mediaone.net>
- Date: Fri, 6 Apr 2001 01:53:17 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
Is there a simple way to perform a change of variables when integrating in a
symbolic form? I'm writing a paper, and would like to express certain
results in an unevaluated dimensionless form even though I started in a
dimensional form. I know I can check things by hand, but would prefer
Mathematica to do the work for me. Here is a sample double integration I
want expressed in dimensionless form:
Integrate[ E^(-y u/d) p[x],{x,0,-a},{y,0,b}]
Here, x, y, a, b, p, u, and d are all dimensional. I want to define new
dimensionless variables and parameters as follows:
xh=x/a
yh=y/b
ph[xh]=p[xh a]/p0
pe=b u/d
Here, p0 has the same dimensions as p, and pe is a dimensionless parameter.
Regards,
Loren Dill