Archive for the ‘Group identical values’ Category

Seeking an efficient algorithm to group identical values

Saturday, February 18th, 2012

Seeking an efficient algorithm to group identical values a post by Daniel Lemire from 2008.

Grouping identical values is a common operation for topic map engines. Daniel’s post and the comments on it should prove helpful to anyone seeking to solve that problem.

Just from a dirty search, I found that LINQ has “GroupBy(v => v)” for this operation (November of 2011).

And, IBM’s Cognos Business Intelligence software has a group by identical value function.

I suspect other BI software has a similar “group by identical value” capability.

Occurs to me that depending on the scripting/programming capabilities of BI software with “group by identical value” functions, it should be possible to create merging capabilities in that software.

The “merging” being what happens after you have grouped a set of items by some identical value set.

That would work for identical values but doesn’t do anything for groups of different values that should lead to merging.

Anyone working with these or other software packages with “group by identical value” functions?

Thinking it may be easier to offer an extension or service of merging that doesn’t rely on changing software.