Piecewise and multiple values
- To: mathgroup at smc.vnet.net
- Subject: [mg89980] Piecewise and multiple values
- From: Giacomo Ciani <jackspam79 at gmail.com>
- Date: Wed, 25 Jun 2008 06:31:08 -0400 (EDT)
Hi all,
in brief my problem: I'm using mathematica to create the solutions for
problems that actually came in few different versions (meaning that
the problem in the same, but the initial data change). Suppose I ave
version 1 in which m=3,k=1,..., version 2 in which m=5,k=2,... and so
on... Typically, I use an approach like:
data={m->{3,5,6},k->{1,2,7},...}
Then I write and solve the general symbolic equations, and the replace
the values with the above rule, like:
sol = Solve[...]
sol/.data
obtaining a list of numerical solutions corresponding to the different
set of data contained in the "data" list, like:
{(num sol corresponding to m=3,k=5,...),(num sol corresponding to
m=5,k=2,...)}
This works very well for me, because it allows me to solve the problem
once and check the numerical solution for all the different versions
at a glance.
The problem arises in the case I have to use a Piecewise function. In
this case I define:
| f x<z
h = |
| g x>z
but when I evaluate
f/.data
I obtain something like:
| {f1,f2,...} x<{z1,z2,...}
h = |
| {g1,g2,...} x>{z1,z2,...}
that I don't know how to plot or "disentagle", i.e. obtain expressions
like:
| f1 x<z1
h1 = |
| g1 x>z1
| f2 x<z2
h2 = |
| g2 x>z2
and so on...
Do you have any suggestion? I would prefer to retain my data
replacement scheme, and just understand how to create "disentangled"
piecewise functions...
Thaks
Giacomo