Hi Paul, I have a suggestion but also a more general observation.
I have also been solving simultaneous linear equations of the form A * x =
b. My first thought was to use the method:
x = A \ b
and it seemed to me that if Tunji's equations are well-behaved then this
may be the easiest method, rather than using 'linsolve'.
In my case I'm trying to solve electrical circuit equations which are
sparse and include complex values. I used x = A \ b to begin with but for
some component values I get messages like:
Warning :
matrix is close to singular or badly scaled. rcond = 1.0388D-08
computing least squares solution. (see lsq).
The method goes to completion but the results are obviously wrong.
If I use 'linsolve' instead, it goes to completion without producing any
warnings or errors but the results are wrong.
For me, 'umfpack' is the best method by far and works very well.
This is a situation which has occurred several times before. SciLab is a
very powerful piece of software and as a result there may (apparently) be
several methods of doing the same thing but there are rarely explanations
of how each method works or why you would use one method rather than
another.
Best wishes,
Adrian.
Adrian Weeks
Development Engineer
HID Global,
3 Cae Gwyrdd,
Green Meadow Springs
Business Park,
Cardiff CF15 7AB,
United Kingdom.
+44 (0)29 20528523
(Office)
[email protected]
www.hidglobal.com
From: Paul Bignier <[email protected]>
To: "International users mailing list for Scilab."
<[email protected]>, [email protected]
Date: 18/03/2014 10:01
Subject: Re: [Scilab-users] Solving linear simultaneous equations
Sent by: "users" <[email protected]>
Hi Tunji,
linsolve help page contains utilization examples.
If you still cannot use it, please tell us more about the problem you are
trying to solve.
Regards,
Paul
On 03/18/2014 10:16 AM, 'Tunji OTUNNIYI wrote:
Hello:
I am quite a starter here.
Could someone please help me through solving n x n linear
simultaneous equations.
I saw linsolve in help, but can’t follow through the arguments.
Applying the calling sequence to a simple example will be of help.
Thanks a lot.
Tunji OTUNNIYI | MME SEET FUTA Akure, Nigeria.
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Paul BIGNIER
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