APLX to remove single 1s from a mask

Question

Does someone know how to remove sinlge 1s from a bit mask using APLX? Example: 1 0 1 1 1 0 0 1 0 1 to 0 0 1 1 1 0 0 0 0 0

Hints greatly appreciated.

I think it is considered good form to mark a correct answer as correct. If you don't, people might stop answering your questions. It looks like Tobia has answered two of your questions so far. — Paul Mansour, Mar 10 '14 at 23:04

score 1 · Answer 1 · answered Mar 09 '14 at 23:57

1

This is one way:

      b←1 0 1 1 1 0 0 1 0 1
      1↓e∧(¯1⌽e)∨1⌽e←0,b
0 0 1 1 1 0 0 0 0 0

It gives an 1 if there is an 1 in the original vector, either followed or preceded by 1.

answered Mar 09 '14 at 23:57

Tobia

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score 0 · Answer 2 · answered Mar 09 '14 at 16:36

Here is one way. First, use the find function to locate all occurrances of 2 consecutive 1's, then use a shift and compare technique to extend all the runs of 1's by 1:

      a←1 0 1 1 1 0 0 1 0 1
      b←1 1⍷a
      b
0 0 1 1 0 0 0 0 0 0
      b∨0,¯1↓b
0 0 1 1 1 0 0 0 0 0

APLX to remove single 1s from a mask

2 Answers2