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Alexey Podchufarov

A problem with functions Flatten; Position; Nearest

Alexey Podchufarov, own
Posted 9 years ago
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Hi all!
I'm trying to find nearest to "a" elements of arrays "m5","m6" and take its indexes (in this arrays) for some computations (not connected with this problem).
After some attempts, i find a solution:

Print[ " PosNear5= ", Flatten[Position[m5, Flatten[Nearest[m5, a]][[1]]], 3], " PosNear6= ", Flatten[Position[m6, Flatten[Nearest[m6, a]][[1]]]][[1]]] ]

the result is:

PosNear5= {121} PosNear6= 108

The second index is ok, but there is the question: Maybe, exist a more simple construction (in my variant - too many functions & brackets). (I want to see index without any figure brackets - for next step computations)...
POSTED BY: Alexey Podchufarov
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Try something like this (using Daniel's suggestion):

nearestIndex[list_, a_] :=
  Nearest[list -> Range[Length[list]], a][[1]];

{pos5 -> nearestIndex[m5, a],
 pos6 -> nearestIndex[m6, a]}
POSTED BY: Antonio Marquez-Raygoza

To get the position(s) you can use Nearest[values->Range[Length[values], a]. That should allow you to avoid Position. No idea why Flatten is needed without seeing your actual example.
POSTED BY: Daniel Lichtblau
Bill Simpson
Bill Simpson
Posted 9 years ago

If you could edit your posting to include a small example with all the data, what the solution should be and why then it might be more likely that you would get good answers more quickly.
POSTED BY: Bill Simpson
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