MathCAD Help Needed

Forum|Forum|15 years ago
September 11, 2010
4 replies
4339 views

Hello,

I am writing a simple routine to exchange the rows, columns or both of a symmetric matrix. Prior to doing so, the routine must catch errors and display them together (if multiple errors are present, they must be listed as separate lines but in a single execution of routine). My routine works, but I cannot figure out how to catch and display the errors properly.

I have attached my code. Any help much appreciated.

1_DMSample-xmcd.zip

Other

J

jeanGiraud

1-Visitor

1. Not clear what the switched product is ! ?

2.The "error test" depends upon what the

symmetric matrix represents.

Monkey don't see, monkey can't help .

jmG

D

DenisMartens

Author

1-Visitor

Jean,

The symmetric matrix does not represent anything in particular at this point. I simply cannot figure out how to display three different errors simultaneously. That is, I can only display the first error which my routine catches (the routine exits once the error occurs). I want to display all errors which occur (total of 3 possible types in my program). Have a look at my code if you can. Sorry if this is a silly thread, I am a newbie to MathCAD and I have to say that although it is a great calculating tool, writing algorithms with this software is a bit painful :/.

Thanks again for the help.

J

jeanGiraud

1-Visitor

Denis Martens wrote:
Jean,
The symmetric matrix does not represent anything in particular at this point. I simply cannot figure out how to display three different errors simultaneously. That is, I can only display the first error which my routine catches (the routine exits once the error occurs). I want to display all errors which occur (total of 3 possible types in my program). Have a look at my code if you can. Sorry if this is a silly thread, I am a newbie to MathCAD and I have to say that although it is a great calculating tool, writing algorithms with this software is a bit painful :/.
Thanks again for the help.

Denis,

I can't see your code, I'm Mathcad 11.

Some collab will surely be curious of what you are attempting.

Cheers, Jean

J

jeanGiraud

1-Visitor

What you let understand is that some stuff should result in a symmetric matrix and that if it is not symmetric, you then want to rotate whatever can be in order to make it it symmetric . Immediately, if a result is not correct for some conditions or values , that indicates some boundary in exploiting such a system. I can't see how to rotate 2*3 to make it 7. Has it got something to do about those "PseudoInverse". You must have some source and reference of what is doing what.

R

RichardJ

19-Tanzanite

You have it written in such a way that if the error doesn't exist then S1, S2, and S3 are undefined. In which case you can't concatenate them! You could add an otherwise for each error and assign an empty string, but there is an easier way.

1_DMSample-mcd.zip

R

RichardJ

19-Tanzanite

You have other errors too. Unless you specifiy otherwise, all array indexing in Mathcad starts at 0, not 1. The logic of your first "if" is also wrong: you need "and", not "or". I slightly improved the error handling too.

1_DMSample-mcd.zip