# times, .*

Multiplication

## Description

example

C = A.*B multiplies arrays A and B by multiplying corresponding elements. The sizes of A and B must be the same or be compatible.

If the sizes of A and B are compatible, then the two arrays implicitly expand to match each other. For example, if one of A or B is a scalar, then the scalar is combined with each element of the other array. Also, vectors with different orientations (one row vector and one column vector) implicitly expand to form a matrix.

C = times(A,B) is an alternate way to execute A.*B, but is rarely used. It enables operator overloading for classes.

## Examples

collapse all

Create two vectors, A and B, and multiply them element by element.

A = [1 0 3];
B = [2 3 7];
C = A.*B
C = 1×3

2     0    21

Create two 3-by-3 arrays, A and B, and multiply them element by element.

A = [1 0 3; 5 3 8; 2 4 6];
B = [2 3 7; 9 1 5; 8 8 3];
C = A.*B
C = 3×3

2     0    21
45     3    40
16    32    18

Create a row vector a and a column vector b, then multiply them. The 1-by-3 row vector and 4-by-1 column vector combine to produce a 4-by-3 matrix.

a = 1:3;
b = (1:4)';
a.*b
ans = 4×3

1     2     3
2     4     6
3     6     9
4     8    12

The result is a 4-by-3 matrix, where each (i,j) element in the matrix is equal to a(j).*b(i):

$\mathit{a}=\left[\begin{array}{ccc}{\mathit{a}}_{1}& {\mathit{a}}_{2}& {\mathit{a}}_{3}\end{array}\right],\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathit{b}=\left[\begin{array}{c}{\mathit{b}}_{1}\\ {\mathit{b}}_{2}\\ {\mathit{b}}_{3}\\ {\mathit{b}}_{4}\end{array}\right],\text{\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}}\text{\hspace{0.17em}}\mathit{a}\text{\hspace{0.17em}}.*\text{\hspace{0.17em}}\mathit{b}=\left[\begin{array}{ccc}{\mathit{a}}_{1}{\mathit{b}}_{1}& {\mathit{a}}_{2}{\mathit{b}}_{1}& {\mathit{a}}_{3}{\mathit{b}}_{1}\\ {\mathit{a}}_{1}{\mathit{b}}_{2}& {\mathit{a}}_{2}{\mathit{b}}_{2}& {\mathit{a}}_{3}{\mathit{b}}_{2}\\ {\mathit{a}}_{1}{\mathit{b}}_{3}& {\mathit{a}}_{2}{\mathit{b}}_{3}& {\mathit{a}}_{3}{\mathit{b}}_{3}\\ {\mathit{a}}_{1}{\mathit{b}}_{4}& {\mathit{a}}_{2}{\mathit{b}}_{4}& {\mathit{a}}_{3}{\mathit{b}}_{4}\end{array}\right].$

## Input Arguments

collapse all

Operands, specified as scalars, vectors, matrices, or multidimensional arrays. Inputs A and B must either be the same size or have sizes that are compatible (for example, A is an M-by-N matrix and B is a scalar or 1-by-N row vector). For more information, see Compatible Array Sizes for Basic Operations.

• Operands with an integer data type cannot be complex.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | categorical | duration | calendarDuration
Complex Number Support: Yes

## Version History

Introduced before R2006a

expand all