# mean

Average or mean value of fixed-point array

## Syntax

``M = mean(A)``
``M = mean(A,dim)``

## Description

example

````M = mean(A)` computes the mean value of the real-valued fixed-point array `A` along its first nonsingleton dimension.```

example

````M = mean(A,dim)` computes the mean value of the real-valued fixed-point array `A` along dimension `dim`. `dim` must be a positive, real-valued integer with a power-of-two slope and a bias of 0.The fixed-point output array, `M`, has the same `numerictype` properties as the fixed-point input array, `A`.If the input array, `A`, has a local `fimath`, then it is used for intermediate calculations. The output, `M`, is always associated with the default `fimath`.When `A` is an empty fixed-point array (value = `[]`), the value of the output array is zero.```

## Examples

collapse all

Create a matrix and compute the mean of each column. `A` is a signed `fi` object with a 32-bit word length and a best-precision fraction length of 28 bits.

```A = fi([0 1 2; 3 4 5],1,32); M = mean(A)```
```A = 0 1 2 3 4 5 DataTypeMode: Fixed-point: binary point scaling Signedness: Signed WordLength: 32 FractionLength: 28 M = 1.5000 2.5000 3.5000 DataTypeMode: Fixed-point: binary point scaling Signedness: Signed WordLength: 32 FractionLength: 28```

Create a matrix and compute the mean of each row. `A` is a signed `fi` object with a 32-bit word length and a best-precision fraction length of 28 bits.

```A = fi([0 1 2; 3 4 5],1,32) M = mean(A,2)```
```A = 0 1 2 3 4 5 DataTypeMode: Fixed-point: binary point scaling Signedness: Signed WordLength: 32 FractionLength: 28 M = 1 4 DataTypeMode: Fixed-point: binary point scaling Signedness: Signed WordLength: 32 FractionLength: 28```

## Input Arguments

collapse all

Input array, specified as a vector, matrix, or multidimensional array.

• If `A` is a scalar, then `mean(A)` returns `A`.

• If `A` is an empty fixed-point array (value = `[]`), the value of the output array is zero.

Data Types: `fi`

Dimension to operate along, specified as a positive, real-valued, integer scalar with a power-of-two slope and a bias of 0. If no value is specified, then the default is the first array dimension whose size does not equal 1.

Data Types: `single` | `double` | `int8` | `int16` | `int32` | `int64` | `uint8` | `uint16` | `uint32` | `uint64` | `fi`

## Algorithms

The general equation for computing the `mean` of an array `A`, across dimension `dim` is:

`sum(A,dim)/size(A,dim)`

Because `size(a,dim)` is always a positive integer, the algorithm for computing mean casts `size(A,dim)` to an unsigned 32-bit `fi` object with a fraction length of zero (denote this `fi` object `'SizeA'`). The algorithm then computes the mean of `A` according to the following equation, where `Tx` represents the `numerictype` properties of the fixed-point input array `A`:

`c = Tx.divide(sum(A,dim), SizeA)`

## Extended Capabilities

### C/C++ Code GenerationGenerate C and C++ code using MATLAB® Coder™. 