Matlab Array Operations

Array Operations

• MATLAB has two flavours of Matlab Arithmetic Operations: Matlab Matrix Operations and array operations.
• Array operations are the dot operations — element-wise — as opposed to the matrix operations of Matlab Matrix Operations.
• Mathematical functions in MATLAB default to array operations unless they are explicitly matrix operations: e.g. sin, sqrt, exp, and log are element-wise. The corresponding Matlab Matrix Operations are usually distinguished by an m suffix, e.g. sqrtm, expm, logm, mtimes, mpower.

Operators

The basic unary and binary array operations all have an operator form:

Operator	Equivalent Function
+	plus
-	minus
.*	times
./	rdivide
.\	ldivide
.^	power

Notes

• All of the array operations above are binary; their operands must satisfy Matlab Compatible Array Sizes. The operation is performed by first expanding both operands to a common size, then applying the operation element-by-element on equal indices

  • For example:

    >> a = [1 2 3]; b = [1 2 3]';
    >> a .* b % equivalent to repmat(a,3,1) .* repmat(b,1,3)
    ans =
        1     2     3
        2     4     6
        3     6     9

• Addition and subtraction coincide for array and matrix operations, so there is no separate dotted form

• A ./ B divides element-wise with A as the numerator and B as the denominator

• A .\ B divides element-wise with A as the denominator and B as the numerator