Section: Mathematical Operators
y = a .\ b
where a
and b
are n
-dimensional arrays of numerical type. In the
first case, the two arguments are the same size, in which case, the
output y
is the same size as the inputs, and is the element-wise
division of b
by a
. In the second case, either a
or b
is a scalar,
in which case y
is the same size as the larger argument,
and is the division of the scalar with each element of the other argument.
The type of y
depends on the types of a
and b
using type
promotion rules, with one important exception: unlike C
, integer
types are promoted to double
prior to division.
If a
is a scalar, then the output is computed via
On the other hand, if b
is a scalar, then the output is computed via
.\
operator. The first example
is straightforward:
--> 3 .\ 8 ans = <double> - size: [1 1] 2.6666666666666665
Note that this is not the same as evaluating 8/3
in C
- there,
the output would be 2
, the result of the integer division.
We can also divide complex arguments:
--> a = 3 + 4*i a = <dcomplex> - size: [1 1] 3+ 4i --> b = 5 + 8*i b = <dcomplex> - size: [1 1] 5+ 8i --> c = b .\ a c = <dcomplex> - size: [1 1] 0.5280898876404494-0.0449438202247191i
If a complex
value is divided by a double
, the result is
promoted to dcomplex
.
--> b = a .\ 2.0 b = <dcomplex> - size: [1 1] 0.24-0.32i
We can also demonstrate the three forms of the dot-left-divide operator. First the element-wise version:
--> a = [1,2;3,4] a = <int32> - size: [2 2] Columns 1 to 2 1 2 3 4 --> b = [2,3;6,7] b = <int32> - size: [2 2] Columns 1 to 2 2 3 6 7 --> c = a .\ b c = <double> - size: [2 2] Columns 1 to 2 2.00 1.50 2.00 1.75
Then the scalar versions
--> c = a .\ 3 c = <double> - size: [2 2] Columns 1 to 2 3.00 1.50 1.00 0.75 --> c = 3 .\ a c = <double> - size: [2 2] Columns 1 to 2 0.3333333333333333 0.6666666666666666 1.0000000000000000 1.3333333333333333