(octave.info)Comparison Ops

---

Next: Boolean Expressions Prev: Arithmetic Ops Up: Expressions

---

Enter node , (file) or (file)node

8.4 Comparison Operators
========================

“Comparison operators” compare numeric values for relationships such as
equality.  They are written using _relational operators_.

   All of Octave’s comparison operators return a value of 1 if the
comparison is true, or 0 if it is false.  For matrix values, they all
work on an element-by-element basis.  Broadcasting rules apply.  Note:
Broadcasting.  For example:

     [1, 2; 3, 4] == [1, 3; 2, 4]
          ⇒  1  0
              0  1

   According to broadcasting rules, if one operand is a scalar and the
other is a matrix, the scalar is compared to each element of the matrix
in turn, and the result is the same size as the matrix.

‘X < Y’
     True if X is less than Y.

‘X <= Y’
     True if X is less than or equal to Y.

‘X == Y’
     True if X is equal to Y.

‘X >= Y’
     True if X is greater than or equal to Y.

‘X > Y’
     True if X is greater than Y.

‘X != Y’
‘X ~= Y’
     True if X is not equal to Y.

   For complex numbers, the following ordering is defined: Z1 < Z2 if
and only if

       abs (Z1) < abs (Z2)
       || (abs (Z1) == abs (Z2) && arg (Z1) < arg (Z2))

   This is consistent with the ordering used by “max”, “min” and “sort”,
but is not consistent with MATLAB, which only compares the real parts.

   String comparisons may also be performed with the ‘strcmp’ function,
not with the comparison operators listed above.  Note: Strings.

 -- : eq (X, Y)
     Return true if the two inputs are equal.

     This function is equivalent to ‘X == Y’.

     See also: Note: ne, Note: isequal, *note le:
     XREFle, Note: ge, Note: gt, Note: ne, Note:
     lt.

 -- : ge (X, Y)
     This function is equivalent to ‘X >= Y’.

     See also: Note: le, Note: eq, Note: gt,
     Note: ne, Note: lt.

 -- : gt (X, Y)
     This function is equivalent to ‘X > Y’.

     See also: Note: le, Note: eq, Note: ge,
     Note: ne, Note: lt.

 -- : isequal (X1, X2, ...)
     Return true if all of X1, X2, ... are equal.

     See also: Note: isequaln.

 -- : isequaln (X1, X2, ...)
     Return true if all of X1, X2, ... are equal under the additional
     assumption that NaN == NaN (no comparison of NaN placeholders in
     dataset).

     See also: Note: isequal.

 -- : le (X, Y)
     This function is equivalent to ‘X <= Y’.

     See also: Note: eq, Note: ge, Note: gt,
     Note: ne, Note: lt.

 -- : lt (X, Y)
     This function is equivalent to ‘X < Y’.

     See also: Note: le, Note: eq, Note: ge,
     Note: gt, Note: ne.

 -- : ne (X, Y)
     Return true if the two inputs are not equal.

     This function is equivalent to ‘X != Y’.

     See also: Note: eq, Note: isequal, *note le:
     XREFle, Note: ge, Note: lt.