Skip to main content
Question

n-ary summation in expression evaluator

  • September 11, 2018
  • 3 replies
  • 6 views

jdh
Contributor
Forum|alt.badge.img+37
  • Contributor
  • 2002 replies

Is there any way to calculate an n-ary summation in the expressionEvaluator or equivalent?

I have an expression to calculate that includes the following component, where n and a are attributes:

?na2n-1

This post is closed to further activity.
It may be an old question, an answered question, an implemented idea, or a notification-only post.
Please check post dates before relying on any information in a question or answer.
For follow-up or related questions, please post a new question or idea.
If there is a genuine update to be made, please contact us and request that the post is reopened.

3 replies

jdh
Contributor
Forum|alt.badge.img+37
  • Author
  • Contributor
  • 2002 replies
  • September 11, 2018

Although I would still be interested in the general case of summation, in this specific case, I was able to use some identities and geometric series to reduce the equation to a(2n+1-1).


siennaatsafe
Safer
Forum|alt.badge.img+12
  • Safer
  • 214 replies
  • September 11, 2018

Hi @jdh,

Thank you for your question. You may wish to try using the RCaller if you're interested in a more advanced calculation. Here is RCaller: Ins and outs of using R in FME. I found an example of summation in the R documentation. While there is a learning curve to using R it is very useful for statistical calculations and I've found the documentation is very useful. Hope that helps!


jdh
Contributor
Forum|alt.badge.img+37
  • Author
  • Contributor
  • 2002 replies
  • September 12, 2018

Hi @jdh,

Thank you for your question. You may wish to try using the RCaller if you're interested in a more advanced calculation. Here is RCaller: Ins and outs of using R in FME. I found an example of summation in the R documentation. While there is a learning curve to using R it is very useful for statistical calculations and I've found the documentation is very useful. Hope that helps!

Hi Sienna,

 

 

I was checking to see if there was a way to do it in "native fme". I can do the calculation in python easily enough, and that doesn't require having R installed.