Sorting set of data by value while keeping the original index

Hi All,

I'm wondering what is the easiest way to filter and sort a set of real numbers by their value while keeping their original index number. The purpose of the exercise is to pick certain objects out of a larger set based on some attributes, and then be able to find them in the original list, using the index number.

Here is the example: I created a large set of geometries. then I created a list from their volumes. My approach was to take this list and use "Dispatch" tool to filter and then rank results. First problem; I don't know how exactly I should write the expression for F(x) that filters results for " x < 10000 ". Second I don't know how to keep the original index numbers in the two resulting lists. I would like these original indexes to refer to the same values even after I sort them by their value.

I appreciate any help.

Best,

Yavar

Replies to This Discussion

Permalink Reply by David Rutten on April 19, 2012 at 1:54am

Hi Yavar,

there's two common ways to approach this.

Create the indices as a list of integers. You can use [List Length] and [Series] to create this list. Then, sort both your numeric values and your indices synchronously, i.e. using the same Sort component. You then still know which numbers came from which index.
Sort your numbers and do whatever else you need to do (but don't change them). Then use [Item Index] to figure out where they used to be stored in the original list. But for this approach it is vital you do not modify the numbers in any way, or they will become different numbers and [Item Index] won't work any more.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by yavar khonsari on April 19, 2012 at 12:11pm