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[Free42] root finder
06-15-2016, 01:39 PM (This post was last modified: 06-15-2016 02:13 PM by Marcio.)
Post: #4
RE: [Free42] root solving
This is the program, quite straight-forward, no optimization attempt:
Code:
LBL "BALL"
MVAR "T"
RCL "T"
+/-
20
/
EXP
+/-
1
+
5000
x
RCL "T"
200
x
-
RTN

Free42 requires one estimate only. I tried a bunch of them now (2,3,4,5) and couldn't replicate the problem I had last night. However, if you enter T as 0.25, Free42 will return a *very* small value, which we assume to be zero. After this, Free42 will give the correct answer for t >0 if t is greater than 3*, sometimes greater 9. I will have to elaborate on this. If you keep playing with it, you will notice this "minimum" value required for the estimate to work changes. I suspect some kind of non-deterministic algorithm is being called here.

Once it finds the root for t>0, which is 9.2843... it won't converge to 0 zero again unless the estimate is also zero. That is when you can't do anything further and some sort of "reset" on the solver is necessary so that other roots (different from 0) can be found. A simple integration will do the job.

*The 15C's solver is even less tolerant and demands the estimates be greater than 5.
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Messages In This Thread
[Free42] root finder - Marcio - 06-15-2016, 12:23 AM
RE: [Free42] root finder - Dieter - 06-15-2016, 10:09 PM
RE: [Free42] root solving - Dieter - 06-15-2016, 01:03 PM
RE: [Free42] root solving - Marcio - 06-15-2016 01:39 PM
RE: [Free42] root solving - Dieter - 06-15-2016, 07:18 PM
RE: [Free42] root finder - Marcio - 06-15-2016, 09:12 PM
RE: [Free42] root finder - Dieter - 06-15-2016, 10:04 PM
RE: [Free42] root finder - Marcio - 06-16-2016, 03:04 PM
RE: [Free42] root finder - Dieter - 06-16-2016, 05:14 PM
RE: [Free42] root finder - Marcio - 06-16-2016, 06:41 PM
RE: [Free42] root finder - Thomas Okken - 06-19-2016, 11:18 PM



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