FindRowInMatrix

Returns a Boolean with 1 for all the rows in matrix AM that match the vector AV:

      AM^.=AV

The length of the vector AV must match the number of columns in the matrix AM.

Thanks to scalar extension the expression also works with a scalar on the right side.

Examples

Add proper examples here, and don't forget to fix a sample function changing "PhraseName" accordingly

      ⎕FX ⍕2 1⍴'r←AM FindRowInMatrix AV' 'r←AM^.=AV'    ⍝ This will work in any APL dialect
      AM←⊃'Barak Obama' 'George Bush' 'Bill Clinton' 'Ronald Reagan' 'Gerald Ford' 'John Kennedy'
      AV←'Ronald Reagan'
      AM FindRowInMatrix AV
0 0 0 1 0 0
      (AM,[0]AM) FindRowInMatrix AV
0 0 0 1 0 0 0 0 0 1 0 0

How not to do it!

Transforming the matrix into a nested vector and then using ≡¨ is more expensive and therefore slower:

     (⊂[1]#.AM)≡¨⊂#.AV

In Dyalog it is about 24% slower than the phrase .

Compatibility

Checked with: APLX, NARS2000, Dyalog APL2, APLX, APL+Win, Dyalog, NARS2000 - Add as many as you can/like

Test Cases

Replace "PhraseName" accordingly Show Hide test cases test cases

Test
 ⎕IO←0      ⍝ You may change this; however, zero IS the default in the Phrasebook
⍝⎕ML←3      ⍝ Enable this line in Dyalog APL if appropriate
  ⎕FX ⍕2 1⍴'r←AM FindRowInMatrix AV' 'r←AM^.=AV'    ⍝ This will work in any APL dialect
⍝ ---- Start Test cases (do not delete this!)
0 0 0 1 ≡ (⊃'Barak Obama' 'George Bush' 'Bill Clinton' 'Ronald Reagan') FindRowInMatrix 'Ronald Reagan'
⍬≡(0 13⍴' ') FindRowInMatrix 'Ronald Reagan'
0 0 0 1 0 0≡(⊃6/¨⍳6) FindRowInMatrix 3
0 0 0 0 0 0≡(⊃6/¨⍳6) FindRowInMatrix 7

Test my code, both Examples and Test Cases.

See also: FindRowsInMatrix

Mentor: KaiJaeger

CategoryPhrasesAll CategoryPhraseSelection