while cycle with functions

Question

while cycle with functions

crashkeeper (Structural)

(OP)

13 Feb 08 07:32

Hi, i would like to do a while cycle with functions inside. i have tried but seems that mathcad dont like functions inside.
what i want to do is augment a matrix i times like this:

CODE

A(x)=| f(x) 0 | <- this is a matrix with a function
| 0 f(x) |

i want my while cycle to augment N(x) matrix with A(x) to result in this:

CODE

N(x)=| f(x) 0 f(x) 0 ... |
| 0 f(x) 0 f(x)..|

so the cycle i have made is:

CODE

A(x):= | f(x)    0  |
       |  0     f(x)|
i:=0
N(x):= while i<3
         A(x) <- augment(A(x),N(x))
         i:=i+1

N(x)-> doenst calculate. it takes lot of time and nothin

Can you please help me in this problem?
thanks

PNachtwey (Electrical) · Answer 1 · 2008-02-13 09:10:56

I would remove the recursive call. That is why your computer hangs up.

CODE

A(x):= | f(x)    0  |
       |  0     f(x)|
i:=0
N(x):= while i<3
                               vvv  Recursive call
         A(x) <- augment(A(x),N(x))
         i:=i+1

I didn't think you could increment a global variable "i" from inside the subroutine. Just local variables.

crashkeeper (Structural) · Answer 2 · 2008-02-13 13:08:01

but i need that call N(x) to augment the matrix.
that means that i want to enlarge matrix A(x) with N(x) from the left to the right.
If i remove N(x) i cant augment the matrix.

i can do it manually, with no while cycle and i can do it too with a while cycle without functions. if i use constants instead of functions that routine works.

about the increasing variable i, i have it inside the routine, that is a mistake.

Thanks anyway :)

philipoakley (Aerospace) · Answer 3 · 2008-02-20 11:20:08

post the sheet on the collab http://collab.mathsoft.com/~Mathcad2000 to get a better response.
P.

bbrnx19 (Civil/Environmental) · Answer 4 · 2008-02-20 15:10:15

try this program

|i<-0 ->
|M<-N(x)
|while i<3
| |i<-1+1
| |M<-augment(A(x),M)

ChrMeissner (Mechanical) · Answer 5 · 2008-02-21 04:11:48

Hello,

see the following image:

(german "erweitern" = engl. "augment")

The MathCAD sheet is avaible at:

http://home.arcor.de/Chr_Meissner/Public/Forum/Forum_engtips_Matrix.xmcd

Christian

philipoakley (Aerospace) · Answer 6 · 2008-03-03 17:10:04

I think you will need to use the symbolic capability if you want to grow the functional form.

I'm sure it can be done. there are some examples such as Tom Gutman's Hessian, Ravel, etc. utilities on the http://collab.mathsoft.com/~Mathcad2000 forum.

The live symbolic can be called within a programme!

Philip

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while cycle with functions