Returning multiple variables from a while loop

[efarquharson]

Hi,

I have been trying to get a while loop to augment multiple matrices, previously defined globally,  until convergence is reached. I then want to access these matrices outside of the loop to perform further calculations. I have been having no luck, and am not even sure if I have defined the loop correctly to draw from the global variables. If you have any ideas, i would be incredibly appreciative.
Thanks so much,

[LucMeekes]

Your function Convergence() takes alot of parameters, but it is ill defined.

Success!
Luc

[efarquharson]

Great, Thanks Luc.

If I were to create this loop without parameters, would I be able to access the global variables from within the loop? Would I have to locally assign them to another variable within the loop?

Thanks so much,

[LucMeekes]

In programs, Mathcad works with variables much like ordinary programming languages do.

If you use a variable, and it is defined (and has a valid value) within the program, that value will be used.

If it is not defined within the program, Mathcad will use a global variable (defined left/above the start of the program) if it exists.

If it can't find the variable in either way, an error results. Here is a simple example of a function that results in a value dependent on a global, and a local variable and a parameter.

Now if you change the function like this:

You see that the global parameter is not used, but it still exists outside of the function.

Success!
Luc

[efarquharson]

Thanks so much again, Luc. I really can't tell you how much I appreciate your help.

I am coming across another error that is making me think this loop isn't taking my global variables:

Mathcad isn't recognizing b_uc_cp as a matrix, but if i check its value outside:

It seems to be a matrix.

Do you have any idea what might be going on?

Thanks so much again

[efarquharson]

for some reason, if I call each variable within the loop it works.

Weird.
Thanks so much again luc!

[LucMeekes]

The b_uc_cp matrix has a unit 'm' (it's a unit, that's why it is coloured blue)

{And to comply with ISO standards it should be upright (roman) font instead of slanted (italic) font, but that's another discussion}

In the condition for the while loop, you call the max() function, the first argument to that is 0.1*m, where 'm' is not displayed as a unit. So I guess Prime takes 'm' to be a variable. Change the 'label' of that 'm' to be 'unit' and see if that helps.

To change the 'label', put the cursor on the 'm' and choose from the menu:

Success!
Luc

[LucMeekes]

Then, in the first iteration, the condition for the while loop should come out as:

so:

The result '1' here means true, so the body of the while statement is executed.

It would also be executed if

Are you sure that's what you want?

Luc