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Hello Adrian,<br>
<br>
Indeed the '\' operator is easy-to-use and powerful (Lapack-based).
I advised it in a private exchange with Tunji (which should have
been made public):<br>
<br>
"<br>
Let's call your 6x6 matrix 'M'.<br>
<br>
Try --> res = M(:,1:5) \ Mat(:, 6)<br>
<br>
The idea is to divide M into a right-hand side ('b' in linsolve
page) and a left-hand side ('A') and use the '\' solving operator.<br>
<br>
If you want a function to enter your coefficients directly, you can
write it:<br>
<br>
function res = mySolve(M)<br>
res = M(:,1:5) \ Mat(:, 6);<br>
endfunction<br>
"<br>
<br>
Regards,<br>
Paul<br>
<br>
<br>
<div class="moz-cite-prefix">On 03/19/2014 10:47 AM,
<a class="moz-txt-link-abbreviated" href="mailto:aweeks@hidglobal.com">aweeks@hidglobal.com</a> wrote:<br>
</div>
<blockquote
cite="mid:OFCAF1F19A.EEC2BFEE-ON80257CA0.0032EC29-80257CA0.0035BC9D@prox.com"
type="cite">
<p><font face="sans-serif" size="2">Hi Paul,</font><br>
<br>
<font face="sans-serif" size="2">I have a suggestion but also a
more general observation.</font><br>
<br>
<font face="sans-serif" size="2">I have also been solving
simultaneous linear equations of the form A * x = b. My first
thought was to use the method:</font><br>
<br>
<font face="sans-serif" size="2"> x = A \ b</font><br>
<br>
<font face="sans-serif" size="2">and it seemed to me that if
Tunji's equations are well-behaved then this may be the
easiest method, rather than using 'linsolve'.</font><br>
<br>
<font face="sans-serif" size="2">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:<br>
</font><br>
<font face="sans-serif" size="2"> Warning :</font><br>
<font face="sans-serif" size="2"> matrix is close to singular or
badly scaled. rcond = 1.0388D-08</font><br>
<font face="sans-serif" size="2"> computing least squares
solution. (see lsq).</font><br>
<br>
<font face="sans-serif" size="2">The method goes to completion
but the results are obviously wrong.</font><br>
<font face="sans-serif" size="2">If I use 'linsolve' instead, it
goes to completion without producing any warnings or errors
but the results are wrong.</font><br>
<font face="sans-serif" size="2">For me, 'umfpack' is the best
method by far and works very well.</font><br>
<br>
<font face="sans-serif" size="2">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.</font><br>
<br>
<font face="sans-serif" size="2">Best wishes,</font><br>
<br>
<font face="sans-serif" size="2">Adrian.</font><br>
<br>
<br>
<table border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr valign="top">
<td class="t" valign="middle" width="178">
<ul style="padding-left: 1pt">
<font color="#333333" face="Arial" size="2"><b>Adrian
Weeks </b></font><font color="#666666"
face="Arial" size="1"><br>
Development Engineer <br>
<br>
<br>
HID Global,<br>
3 Cae Gwyrdd,<br>
Green Meadow Springs<br>
Business Park,<br>
Cardiff CF15 7AB,<br>
United Kingdom.<br>
+44 (0)29 20528523 (Office)</font><font
color="#0000FF" face="Arial" size="1"><u><br>
</u></font><a moz-do-not-send="true"
href="mailto:aweeks@hidglobal.com"><font
color="#0000FF" face="Arial" size="1"><u>aweeks@hidglobal.com</u></font></a><font
color="#0000FF" face="Arial" size="1"><u><br>
</u></font><a moz-do-not-send="true"
href="http://www.hidglobal.com/"><font
color="#0000FF" face="Arial" size="1"><u>www.hidglobal.com</u></font></a>
</ul>
</td>
<td valign="middle" width="139">
<ul style="padding-left: 1pt">
<a moz-do-not-send="true"
href="http://www.hidglobal.com/"><img
src="cid:part3.02010501.02070409@scilab-enterprises.com"
border="0" height="170" width="130"></a>
</ul>
</td>
</tr>
</tbody>
</table>
<br>
<br>
<img src="cid:part5.03040407.02040503@scilab-enterprises.com"
alt="Inactive hide details for Paul Bignier ---18/03/2014
10:01:09---Hi Tunji, linsolve help page" border="0"
height="16" width="16"><font color="#424282" face="sans-serif"
size="2">Paul Bignier ---18/03/2014 10:01:09---Hi Tunji,
linsolve help page</font><br>
<br>
<table border="0" cellpadding="0" cellspacing="0" width="100%">
<tbody>
<tr valign="top">
<td width="1%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="96"><br>
<ul style="padding-left: 4pt">
<font color="#5F5F5F" face="sans-serif" size="1">From:</font>
</ul>
</td>
<td width="100%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="1"><br>
<font face="sans-serif" size="1">Paul Bignier
<a class="moz-txt-link-rfc2396E" href="mailto:paul.bignier@scilab-enterprises.com"><paul.bignier@scilab-enterprises.com></a></font></td>
</tr>
<tr valign="top">
<td width="1%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="96"><br>
<ul style="padding-left: 4pt">
<font color="#5F5F5F" face="sans-serif" size="1">To:</font>
</ul>
</td>
<td width="100%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="1"><br>
<font face="sans-serif" size="1">"International users
mailing list for Scilab."
<a class="moz-txt-link-rfc2396E" href="mailto:users@lists.scilab.org"><users@lists.scilab.org></a>, <a class="moz-txt-link-abbreviated" href="mailto:iootunniyi@futa.edu.ng">iootunniyi@futa.edu.ng</a></font></td>
</tr>
<tr valign="top">
<td width="1%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="96"><br>
<ul style="padding-left: 4pt">
<font color="#5F5F5F" face="sans-serif" size="1">Date:</font>
</ul>
</td>
<td width="100%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="1"><br>
<font face="sans-serif" size="1">18/03/2014 10:01</font></td>
</tr>
<tr valign="top">
<td width="1%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="96"><br>
<ul style="padding-left: 4pt">
<font color="#5F5F5F" face="sans-serif" size="1">Subject:</font>
</ul>
</td>
<td width="100%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="1"><br>
<font face="sans-serif" size="1">Re: [Scilab-users]
Solving linear simultaneous equations</font></td>
</tr>
<tr valign="top">
<td width="1%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="96"><br>
<ul style="padding-left: 4pt">
<font color="#5F5F5F" face="sans-serif" size="1">Sent
by:</font>
</ul>
</td>
<td width="100%"><img
src="cid:part6.08030805.01090301@scilab-enterprises.com"
alt="" border="0" height="1" width="1"><br>
<font face="sans-serif" size="1">"users"
<a class="moz-txt-link-rfc2396E" href="mailto:users-bounces@lists.scilab.org"><users-bounces@lists.scilab.org></a></font></td>
</tr>
</tbody>
</table>
</p>
<hr style="color:#8091A5; " align="left" noshade="noshade"
size="2" width="100%"><br>
<br>
<br>
<font face="serif" size="3"><br>
Hi Tunji,<br>
<br>
linsolve </font><a moz-do-not-send="true"
href="http://help.scilab.org/docs/5.4.1/en_US/linsolve.html"><font
color="#0000FF" face="serif" size="3"><u>help page</u></font></a><font
face="serif" size="3"> contains utilization examples.<br>
<br>
If you still cannot use it, please tell us more about the
problem you are trying to solve.<br>
<br>
Regards,<br>
Paul<br>
<br>
</font><br>
<font face="serif" size="3">On 03/18/2014 10:16 AM, 'Tunji
OTUNNIYI wrote:</font>
<ul style="padding-left: 36pt">
<font color="#1F497D" face="Calibri" size="2">Hello:</font><br>
<font face="Calibri" size="2"> </font><br>
<font face="Calibri" size="2">I am quite a starter here.</font><br>
<font color="#1F497D" face="Calibri" size="2"> </font><br>
<font face="Calibri" size="2">Could someone please help me
through solving n x n linear simultaneous equations.</font><br>
<font face="Calibri" size="2">I saw linsolve in help, but can’t
follow through</font><font color="#1F497D" face="Calibri"
size="2"> </font><font face="Calibri" size="2">the arguments.
Applying the calling sequence to a simple example will be of
help.</font><br>
<font face="Calibri" size="2">Thanks a lot.</font><br>
<font face="Calibri" size="2"> </font><br>
<font face="Calibri" size="2">Tunji OTUNNIYI | MME SEET FUTA
Akure, Nigeria.</font><br>
<font face="Calibri" size="2"> </font>
<p><font face="serif" size="3"><br>
</font><br>
<tt><font size="3">_______________________________________________<br>
users mailing list<br>
</font></tt><a moz-do-not-send="true"
href="mailto:users@lists.scilab.org"><tt><font
color="#0000FF" size="3"><u>users@lists.scilab.org</u></font></tt></a><tt><font
size="3"><br>
</font></tt><a moz-do-not-send="true"
href="http://lists.scilab.org/mailman/listinfo/users"><tt><font
color="#0000FF" size="3"><u>http://lists.scilab.org/mailman/listinfo/users</u></font></tt></a><tt><font
size="3"><br>
</font></tt></p>
</ul>
<br>
<tt><font size="3">-- <br>
Paul BIGNIER<br>
Development engineer<br>
-----------------------------------------------------------<br>
Scilab Enterprises<br>
143bis rue Yves Le Coz - 78000 Versailles, France<br>
Phone: +33.1.80.77.04.69<br>
</font></tt><a moz-do-not-send="true"
href="http://www.scilab-enterprises.com/"><tt><font
color="#0000FF" size="3"><u>http://www.scilab-enterprises.com</u></font></tt></a><tt><font
size="3"> </font></tt><tt><font size="2">_______________________________________________<br>
users mailing list<br>
<a class="moz-txt-link-abbreviated" href="mailto:users@lists.scilab.org">users@lists.scilab.org</a><br>
</font></tt><tt><font size="2"><a moz-do-not-send="true"
href="http://lists.scilab.org/mailman/listinfo/users">http://lists.scilab.org/mailman/listinfo/users</a></font></tt><tt><font
size="2"><br>
</font></tt><br>
<br>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:users@lists.scilab.org">users@lists.scilab.org</a>
<a class="moz-txt-link-freetext" href="http://lists.scilab.org/mailman/listinfo/users">http://lists.scilab.org/mailman/listinfo/users</a>
</pre>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Paul BIGNIER
Development engineer
-----------------------------------------------------------
Scilab Enterprises
143bis rue Yves Le Coz - 78000 Versailles, France
Phone: +33.1.80.77.04.69
<a class="moz-txt-link-freetext" href="http://www.scilab-enterprises.com">http://www.scilab-enterprises.com</a> </pre>
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