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For loop and matrices

Forum|Forum|4 years ago
September 30, 2021
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Hello. I am looking for some assistance with for loops and matrices within Mathcad. I have a relatively basic knowledge of mathcad so this may be a straightforward solution.

I am trying to return a value for m11 for each of the sigma(11) values. However, the way i have it set up, it only returns the m11 value when i = 2.

I know i could list the equation out 3 times, changing the "i" with 0, 1, and 2 each time; however i had thought i may be able to do the same thing using the for loop function.

Thank you.

1_TEST.zip

Best answer by LucMeekes

A Mathcad program returns ONLY the value of the last statement executed. That's why you see a single element instead of an array.

Here's what you could do (simplified):

(I could have typed just R, instead of return R, but it makes clear what result the program should return. Note that a return statement put anywhere in the program makes the program stop there and return the argument of the return. So you can put it in a IF statement if you need to stop the program in the middle of a loop.)

But in general I prefer to define a function (prevents strange things happening when the FOR loop gets out of sync with the length of the array):

A word of advice: refrain from evaluating a definition (that is, do NOT put an = immediately following a definition, like you did with m.11). First define m.11 := ....

Then, on a separate spot, evaluate it with m.11 =

Yes, it works (most of the time), but occasionally it creates problems.

Success!
Luc

L

LucMeekes

Answer

23-Emerald IV

A Mathcad program returns ONLY the value of the last statement executed. That's why you see a single element instead of an array.

Here's what you could do (simplified):

(I could have typed just R, instead of return R, but it makes clear what result the program should return. Note that a return statement put anywhere in the program makes the program stop there and return the argument of the return. So you can put it in a IF statement if you need to stop the program in the middle of a loop.)

But in general I prefer to define a function (prevents strange things happening when the FOR loop gets out of sync with the length of the array):

A word of advice: refrain from evaluating a definition (that is, do NOT put an = immediately following a definition, like you did with m.11). First define m.11 := ....

Then, on a separate spot, evaluate it with m.11 =

Yes, it works (most of the time), but occasionally it creates problems.

Success!
Luc

F

FC_10063827

Author

1-Visitor

Thank you for providing this. Very useful information to know for the future. Managed to make both work for my problem too

J

JXBWk

14-Alexandrite

two other possible ways ...

F

FC_10063827

Author

1-Visitor

Thank you for this. Capture 1 works best for me as it was very similar to how the actual calculation I have was laid out.

S

StuartBruff

23-Emerald V

For those who have similar problems but only have Mathcad Prime Express, here are a few other ways around using programmed for loops. They work in Mathcad Prime Express 7 and should work in earlier versions.

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