       Re: Recursive function: What is the proper way to get mathematica to

• To: mathgroup at smc.vnet.net
• Subject: [mg130262] Re: Recursive function: What is the proper way to get mathematica to
• From: debguy <johnandsara2 at cox.net>
• Date: Sat, 30 Mar 2013 04:08:56 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• Delivered-to: l-mathgroup@wolfram.com
• Delivered-to: mathgroup-newout@smc.vnet.net
• Delivered-to: mathgroup-newsend@smc.vnet.net
• References: <kiog04\$3cb\$1@smc.vnet.net>

```Most importantly you need to first ask: when can I use Number
Integration and when must the result of Integration be symbolic in
order to procede with counting?

Let's evaluate that by hand.

Being Integrate I'm Taking Parts of eq'n and expect to yeild a new
equation (or number).  (the Mathematica Book, Principles of
Evaluation)

When I integrate X[i,t] you tell me evaluate X[i,t] to find what to
integrate (the Parts).  I try but the result is always the same: I'm
asked to find X[i,t] again (has not changed).

may as well say:

y[x_]:=y[x]

Also, possibly erroneously in your setup, what is independant or
dependant to integrate changes depending upon whether X[i j,t] or x[i
j,t] is invoked first.

I don't think you want recursion.

If you intend to code recursivly you need a condition of exit.  See
www.wikipedia.com for lessions about recursion and exit as the
Mathematica Book does not explain, ie tail recursion, well.

If you intend to recurse during an integral evaluation you need to
continually evaluate and Integrate does not do that, so maybe Sum[] or
For loop is a better way to begin if you have non-instantaneous
variables / functions to evaluate at each partition of sum.  (possible
NIntegrate with special objects).  You might even plot what is being
summed while it is.

Most importantly you need to first ask: when can I use Number
Integration and when must the evaluation be symbolic.  When can I
state the symbol definition of the equation , and when can i
substitute in it.

```

• Prev by Date: Re: Calling Mathematica from Java (Eclipse)
• Next by Date: Re: Plotting a transition function
• Previous by thread: Recursive function: What is the proper way to get mathematica to
• Next by thread: Insufficient memory "General::nomem:" using Tuples