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MW_121231161-Visitor
1-Visitor
October 11, 2024
Question

Mathcad Prime Integral with change of tolerance

  • October 11, 2024
  • 2 replies
  • 872 views

Hi,

 

I am doing an integral in mathcad prime. The function inside of the integral is a summation of series of if statement functions and a step function (for loop). 

 

I plotted the integral twice (see attached figures), one with a TOL of 0.01  and one with a TOL of 0.1. However, the peak values along the graph are not the same at the same depth and I don't know why they are different since I am integrating the same function. However, the function stops at the same point (where the Moment is 0 kip*ft) at the very bottom. 

 

I am wondering why the peak values are different by changing the tolerance. Thank you.

 

 

 

 

 

2 replies

W
Werner_E25-Diamond I
25-Diamond I
October 11, 2024

Summing a larger number of values with a rather large value like 0.1 for TOL sure can lead to a larger overall inaccuracy.

Keep in mind that numeric integration also is just summation of a larger number of smaller values ...

We have seen quite a number of strange effects with definite numeric integrals here and sometimes it helped to split the integral into parts rather than letting it run over the full interval.

Can you post the worksheet or a smaller stripped down sheet showing the same/similar effect?

 

A
anursinghCommunity Manager
Community Moderator
October 28, 2024

Hi @MW_12123116,

 

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 
 

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