Comparison Functions

All comparison functions are dyadic and scalar. They return 1 (true) or 0 (false) for each element pair. They apply element-wise with scalar extension.

Summary

Glyph	Name	3 f 4	4 f 4
<	Less than	1	0
≤	Less than or equal	1	1
=	Equal	0	1
≥	Greater than or equal	0	1
>	Greater than	0	0
≠	Not equal	1	0

Examples

      3<5
1
      5<3
0
      1 2 3 4 5≥3
0 0 1 1 1
      3=3
1
      3≠3
0

Comparison tolerance (⎕CT)

Comparisons use tolerant comparison for floating-point values. Two numbers a and b are considered equal if:

|a-b| ≤ ⎕CT × (|a| ⌈ |b|)

The default ⎕CT is 1E¯14. This means very small floating-point differences (from rounding) are ignored:

      1=(1÷3)×3          ⍝ tolerant: 0.999... equals 1
1

Set ⎕CT←0 for exact comparison:

      ⎕CT←0
      1=1.001
0

Note

Match (≡) and not-match (≢) always use exact comparison, regardless of ⎕CT.