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# This value must be a scalar2

## This value must be a scalar

(OP)
Hi,

I'm not aware how this could be solved.
Any help would be highly appreciated.

### RE: This value must be a scalar

Is lamba pw a vector as well?

You may want to write a for loop to make this happen. Example from mathcad 15:

S&T - www.re-tug.com

### RE: This value must be a scalar

(OP)

#### Quote (sticksandtriangles)

Is lamba pw a vector as well?
Hi,
I'm sorry if I didn't provide whole data.

### RE: This value must be a scalar

So, you can't compare lambda _w directly to lambda_pw directly, because mathcad doesn't know which value in lambda_w (your vector) to lambda_pw (a scaler).

I imagine that line would work if you did the "vectorization" operator, as per your other thread. In the "Math" tab of the ribbon, click on "Operators" (has a cube root symbol on my version of mathcad), and at the bottom of the drop-down are the Vector and Matrix operators. The one you're looking for is a "V" with an arrow above it.

Make sure to highlight " lambda_w <= lambda_pw " and the apply the operator. Let us know if that fixes your problem.

### RE: This value must be a scalar

(OP)

#### Quote (winelandv)

I imagine that line would work if you did the "vectorization" operator, as per your other thread. In the "Math" tab of the ribbon, click on "Operators" (has a cube root symbol on my version of mathcad), and at the bottom of the drop-down are the Vector and Matrix operators. The one you're looking for is a "V" with an arrow above it.

Make sure to highlight " lambda_w <= lambda_pw " and the apply the operator. Let us know if that fixes your problem.
I'm sorry, but that doesn't fix the problem.
If you note the right side of the image, the comparison is OK. But when dealing with If statement, the problem comes.

### RE: This value must be a scalar

If you stop and think about it, the example you show is actually a programmatic behavior embedded within the "=" functionality, but a program, as shown on the left side, does not use that functionality and must be explicitly programmed for it.

TTFN (ta ta for now)
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### RE: This value must be a scalar

I don't use programming when I use mathcad, so LPS for IRstuff for filling in the missing knowledge.

### RE: This value must be a scalar

Hoshang,

I would make a for loop for your situation, compare lambda w [i] to lambda pw in your for loop.

My example up above should be enough to make you dangerous.

S&T - www.re-tug.com

### RE: This value must be a scalar

(OP)

#### Quote (IRstuff)

the example you show is actually a programmatic behavior embedded within the "=" functionality, but a program, as shown on the left side, does not use that functionality and must be explicitly programmed for it.
I tried several tricks but I couldn't catch this.
I removed the lower two If statements.
I tried with other comparison operators.
I tried also If and else statement instead of lower two If statements.
I tried If( , , , , , ) statement.
But with no success.
Any help will be highly appreciated.

### RE: This value must be a scalar

Just make a vector equal in length to the comparison vector that has the same value in each row.

### RE: This value must be a scalar

(OP)

#### Quote (IRstuff)

If you stop and think about it, the example you show is actually a programmatic behavior embedded within the "=" functionality, but a program, as shown on the left side, does not use that functionality and must be explicitly programmed for it.
Hi,
I know you have so many contribution in PTC Mathcad. So, I hope you be able to give a solution for this problem.

### RE: This value must be a scalar

try something like this:

### RE: This value must be a scalar

(OP)

#### Quote (structSU10)

try something like this:
Accepted as solution. Highly appreciated.

### RE: This value must be a scalar

(OP)
Hi,
This time I've stuck with this:

Any help would be highly appreciated.

### RE: This value must be a scalar

If I'm reading the flow of your program correctly, aren't you checking the compact limit before you check the non-compact limit? If so, you don't need to check if lambda_f is greater than the compact limit. Try and remove the "lambda_pf <" from that line and see if it gets it moving.

### RE: This value must be a scalar

you use the i designation to define the function but none of the parameters have an i attributed to them. your lambda_rf should have an i and the i must be defined for the appropriate range.

### RE: This value must be a scalar

(OP)
Hi, structSU10
Your help is highly appreciated and accepted as solution.
P.S., By accepted as solution, I mean I tried your approach and the problem is solved.

### RE: This value must be a scalar

(OP)
Now another thought came into mind. Please find the attached image:

Is there any way combining these two steps into one step when calculating R_pc2 ?

### RE: This value must be a scalar

(OP)
Hi, I'm sorry if I haven't been clear.
I meant the inclusion of the R_pc2<=M_p2/M_y2 condition into the If statement. How this can be done?

### RE: This value must be a scalar

(OP)
Hi
Can anyone share thoughts with my query?

### RE: This value must be a scalar

So, you're checking Rpc2 to see if it's less than the ratio between its plastic moment and yield moment (the shape factor, if I recall correctly).

So, what happens if Rpc2 exceeds that ratio? I assume you need to check all your Rpc values against the moment ratio?

### RE: This value must be a scalar

(OP)

#### Quote (winelandv)

what happens if Rpc2 exceeds that ratio? I assume you need to check all your Rpc values against the moment ratio?
Thanks, if Rpc2 exceeds that ratio, then R_pc2=M_p2/M_y2.

### RE: This value must be a scalar

It appears to me that you're already (essentially) doing that check with your first statement.

UNLESS, is there ever a case where lambdaw is less than lambdarw, but you could still end up with a value that is greater than your Mp/My? If the answer to this is "no", then you don't need to perform the check separately.

### RE: This value must be a scalar

(OP)
Hi,
Please find the attached image for more clarification.
P.S
Lambda_w=h_c/t_w

### RE: This value must be a scalar

(OP)
Hi
Any input would be highly appreciated.

### RE: This value must be a scalar

(OP)
Hi,
Can't my issue be solved?

### RE: This value must be a scalar

if that is correct you can use the max(1.0,Mp/Myc) in the last statement to force this to work.

### RE: This value must be a scalar

(OP)
Hi structSU10,
Thanks. Should it be max or min function?
Please find the attached image. Am I doing it correctly?

### RE: This value must be a scalar

I think it is min in this case as you are limiting the left side of the inequality to be less than or equal to the right side.

### RE: This value must be a scalar

(OP)
Hi structSU10,
Thanks, I highly appreciate your help.

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