topic Re: need help with iterative loop in Mathcad

Re: need help with iterative loop

DS_14452341 — Fri, 02 Jan 2026 18:19:10 GMT

I have:

And a dropdown with rebar properties:

Areas are in col 2, 0.44, 0.60, 0.79, etc. How can I write an equation that returns the bar size with the largest area exceeding Areqd?

Please advise, thank you

Re: need help with iterative loop

Werner_E — Sat, 03 Jan 2026 08:04:46 GMT

How can I write an equation that returns the bar size with the largest area exceeding Areqd?

I guess you rather mean with the smallest area which still exceeds A_reqd, right?

Unfortunately the dropdown is to be used just for manual selection.

Prime can't access all the data therein automatically.

You need the data in a data structure Prime can work with.

This can be a matrix consisting all the values or a series of individual vectors (nx1 matrices).

You must not but you can use a Prime table to input all the values.

Once the data is here its easy for Prime to select the row needed.

The attached sheet should help. Unless otherwise stated I assume that you are using the current version (11) of Prime.
In case you don't, I attach a pdf print for your information.

Re: need help with iterative loop

terryhendicott — Sun, 04 Jan 2026 13:46:47 GMT

Hi,

Selecting the grade has an influence on the area needed and the threads available for choice at that grade.

Have added to Werner's great sheet:

Two linked list boxes where you can choose the grade in the first list box and this dictates what shows in the second list box. Choose in the second list box and it outputs the area.

The first list box choice of grade is used to choose a suitable bar to match Area required (that varies by grade) and the chosen grade.

New calculations are in the draft area off to the right.

Cheers

Terry

Re: need help with iterative loop

anursingh — Mon, 09 Mar 2026 16:47:01 GMT

Hi @DS_14452341,

I wanted to see if you got the help you needed.

If so, please mark the appropriate reply as the Accepted Solution. It will help other members who may have the same question.
Of course, if you have more to share on your issue, please pursue the conversation.

Thanks,
Anurag