MINUS Subtraction Operator
Section: Mathematical Operators
Usage
Subtracts two numerical arrays (elementwise). There are two forms for its use, both with the same general syntax: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
difference of a
and b
. 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 difference of the scalar to each element of the other argument.
The rules for manipulating types has changed in FreeMat 4.0. See typerules
for more details.
Function Internals
There are three formulae for the subtraction operator, depending on the sizes of the three arguments. In the most general case, in which the two arguments are the same size, the output is computed via:
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
Examples
Here are some examples of using the subtraction operator. First, a straight-forward usage of the minus operator. The first example is straightforward:--> 3 - 8 ans = -5
Next, we subtract a vector of values from a scalar:
--> 3.1 - [2,4,5,6,7] ans = 1.1000 -0.9000 -1.9000 -2.9000 -3.9000
With complex values
--> a = 3 - 4*i a = 3.0000 - 4.0000i --> b = a - 2 b = 1.0000 - 4.0000i
Finally, the element-wise version:
--> a = [1,2;3,4] a = 1 2 3 4 --> b = [2,3;6,7] b = 2 3 6 7 --> c = a - b c = -1 -1 -3 -3