comparison — comparison, relational operators
a==b a~=b or a<>b a<b a<=b a>b a>=b
any type of variable for a==b, a~=b
a<>b equality comparisons and restricted to real floating point and integer
array for order related comparisons a<b,
a<=b, a>b,a>=b.
any type of variable for a==b, a~=b
a< > b equality comparisons and restricted to
real floating point and integer arrays for order related comparisons
a<b, a<=b,
a>b,a>=b.
Two classes of operators have to be distinguished:
a==b, a~=b (or equivalently a<>b).
These operators apply to any type of operands.
a<b, a<=b,
a>b,a>=b. These operators apply
only to real floating point and integer arrays.
The semantics of the comparison operators also depend on the operands types:
like floating point and integer arrays, logical arrays, string arrays, polynomial and rationnal arrays, handle arrays, lists... the following rules apply:
If a and b evaluates as arrays with same types
and identical dimensions, the comparison is performed element by
element and the result is an array of booleans of the same.
If a and b evaluates as arrays
with same types, but a or b is a 1 by
1 array the scalar is compared with each element of the
other array. The result is an array of booleans of the size of
the non scalar operand.
In the others cases the result is the boolean %f
If the operand data types are differents but "compatible" like floating points and integers a type conversion is performed before the comparison.
like function,
libraries, the result is
%t if the objects are identical and %f in the
other cases.
Equality comparison between operands of incompatible data types
returns %f.
//element wise comparisons
(1:5)==3
(1:5)<=4
(1:5)<=[1 4 2 3 0]
1<[]
list(1,2,3)~=list(1,3,3)
//object wise comparisons
(1:10)==[4,3]
'foo'==3
1==[]
list(1,2,3)==1
isequal(list(1,2,3),1)
isequal(1:10,1)
//comparison with type conversion
int32(1)==1
int32(1)<1.5
int32(1:5)<int8(3)
p=poly(0,'s','c')
p==0
p/poly(1,'s','c')==0