Contents Previous Next Subchapters

Testing Numeric And Logical Equality
Syntax left value == right value
left value <> right value
(equal)
(not equal)
See Also ordered , equal , all , any , and string ==

Description
Tests the equality of two logical, integer, real, double-precision or complex values.

Comparisons using the equal (==) and not equal (<>) operators return logical matrices with dimensions equal to the matrices being compared. An element of the result is true (which O-Matrix prints as T) if the condition is true for the corresponding elements of the two matrices, or false (which O-Matrix prints as F) if it is not. If a matrix is compared with a scalar, O-Matrix compares the scalar value with the value of each individual element of the matrix.

Tutorial

Comparing Scalars
If you enter
     x = 4
     y = 8
     print y == x
O-Matrix will respond
     F
O-Matrix does not consider matrix type when testing equality (because it performs coercion before making the test). If you enter
     x = 1
     y = 1.
     print y == x
O-Matrix will respond
     T
even though x is an integer and y is a real number.

Assigning Logical Values
Variables can be set equal to logical values. If you enter
     z = 2 <> 3
     z
O-Matrix will respond
     T
Variables can also be directly assigned the logical values true or false. Entering
     x = true
     x
results in
     T

Comparing Matrices
When testing the equality of two non-scalars, O-Matrix returns a matrix of the same dimension as the matrices being compared. For example, if you enter
     u = { 4, 3, 2, 1, 9 }
     v = { 9, 2, 2, 2, 9 }
     u == v
O-Matrix will respond
     {
     F
     F
     T
     F
     T
     }
If you enter
     x = {[1, 2], [2, 1]}
     y = {[2, 1], [2, 1]}
     x == y
O-Matrix will respond
     {
     [ F , F ]
     [ T , T ]
     }

Comparing Matrices with Scalars
When comparing a matrix with a scalar, the result has the same dimension as the matrix. Each element of the result corresponds to comparing an element of the matrix with the scalar. For example, if you enter
     x = {[1, 2], [3, 4]}
     x == 2
O-Matrix will respond
     {
     [ F , T ]
     [ F , F ]
     }

Reference
If the value types do not agree, O-Matrix will coerce the values as detailed in the coercion section.