# ne, ~=

Determine inequality

## Syntax

``A ~= B``
``ne(A,B)``

## Description

example

````A ~= B` returns a logical array or a table of logical values with elements set to logical `1` (`true`) where inputs `A` and `B` are not equal; otherwise, the element is logical `0` (`false`). The test compares both real and imaginary parts of numeric arrays. `ne` returns logical `1` (`true`) where `A` or `B` have `NaN` or undefined `categorical` elements.```
````ne(A,B)` is an alternative way to execute `A ~= B`, but is rarely used. It enables operator overloading for classes.```

## Examples

collapse all

Create two vectors containing both real and imaginary numbers, then compare the vectors for inequality.

```A = [1+i 3 2 4+i]; B = [1 3+i 2 4+i]; A ~= B```
```ans = 1x4 logical array 1 1 0 0 ```

The `ne` function tests both real and imaginary parts for inequality, and returns logical `1` (`true`) where one or both parts are not equal.

Create a character vector.

`M = 'magenta';`

Test for the presence of a specific character using `~=`.

`M ~= 'q'`
```ans = 1x7 logical array 1 1 1 1 1 1 1 ```

The value of logical `1` (`true`) indicates the absence of the character `'n'`. The character is not present in the vector.

Create a categorical array with two values: `'heads'` and `'tails'`.

`A = categorical({'heads' 'heads' 'tails'; 'tails' 'heads' 'tails'})`
```A = 2x3 categorical heads heads tails tails heads tails ```

Find all values not in the `'heads'` category.

`A ~= 'heads'`
```ans = 2x3 logical array 0 0 1 1 0 1 ```

A value of logical `1` (`true`) indicates a value not in the category. Since `A` only has two categories, `A ~= 'heads'` returns the same answer as `A == 'tails'`.

Compare the rows of `A` for inequality.

`A(1,:) ~= A(2,:)`
```ans = 1x3 logical array 1 0 0 ```

A value of logical `1` (`true`) indicates where the rows have unequal category values.

Many numbers expressed in decimal text cannot be represented exactly as binary floating numbers. This leads to small differences in results that the `~=` operator reflects.

Perform a few subtraction operations on numbers expressed in decimal and store the result in `C`.

`C = 0.5-0.4-0.1`
```C = -2.7756e-17 ```

With exact decimal arithmetic, `C` should be equal to exactly `0`. Its small value is due to the nature of binary floating-point arithmetic.

Compare `C` to `0` for inequality.

`C ~= 0`
```ans = logical 1 ```

Compare floating-point numbers using a tolerance, `tol`, instead of using `~=`.

```tol = eps(0.5); abs(C-0) > tol```
```ans = logical 0 ```

The two numbers, `C` and `0`, are closer to one another than two consecutive floating-point numbers near `0.5`. In many situations, `C` may act like `0`.

Compare the elements of two `datetime` arrays for inequality.

Create two `datetime` arrays in different time zones.

```t1 = [2014,04,14,9,0,0;2014,04,14,10,0,0]; A = datetime(t1,'TimeZone','America/Los_Angeles'); A.Format = 'd-MMM-y HH:mm:ss Z'```
```A = 2x1 datetime 14-Apr-2014 09:00:00 -0700 14-Apr-2014 10:00:00 -0700 ```
```t2 = [2014,04,14,12,0,0;2014,04,14,12,30,0]; B = datetime(t2,'TimeZone','America/New_York'); B.Format = 'd-MMM-y HH:mm:ss Z'```
```B = 2x1 datetime 14-Apr-2014 12:00:00 -0400 14-Apr-2014 12:30:00 -0400 ```

Check where elements in `A` and `B` are not equal.

`A~=B`
```ans = 2x1 logical array 0 1 ```

Since R2023a

Create two tables and compare them. The row names (if present in both) and variable names must be the same, but do not need to be in the same orders. Rows and variables of the output are in the same orders as the first input.

`A = table([1;2],[3;4],VariableNames=["V1","V2"],RowNames=["R1","R2"])`
```A=2×2 table V1 V2 __ __ R1 1 3 R2 2 4 ```
`B = table([4;2],[3;1],VariableNames=["V2","V1"],RowNames=["R2","R1"])`
```B=2×2 table V2 V1 __ __ R2 4 3 R1 2 1 ```
`A ~= B`
```ans=2×2 table V1 V2 _____ _____ R1 false true R2 true false ```

## Input Arguments

collapse all

Operands, specified as scalars, vectors, matrices, multidimensional arrays, tables, or timetables. 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.

You can compare numeric inputs of any type, and the comparison does not suffer loss of precision due to type conversion.

• If one input is a `categorical` array, the other input can be a `categorical` array, a cell array of character vectors, or a single character vector. A single character vector expands into a cell array of character vectors of the same size as the other input. If both inputs are ordinal `categorical` arrays, they must have the same sets of categories, including their order. If both inputs are `categorical` arrays that are not ordinal, they can have different sets of categories. See Compare Categorical Array Elements for more details.

• If one input is a `datetime` array, the other input can be a `datetime` array, a character vector, or a cell array of character vectors.

• If one input is a `duration` array, the other input can be a `duration` array or a numeric array. The operator treats each numeric value as a number of standard 24-hour days.

• If one input is a string array, the other input can be a string array, a character vector, or a cell array of character vectors. The corresponding elements of `A` and `B` are compared lexicographically.

Inputs that are tables or timetables must meet the following conditions: (since R2023a)

• If an input is a table or timetable, then all its variables must have data types that support the operation.

• If only one input is a table or timetable, then the other input must be a numeric or logical array.

• If both inputs are tables or timetables, then:

• Both inputs must have the same size, or one of them must be a one-row table.

• Both inputs must have variables with the same names. However, the variables in each input can be in a different order.

• If both inputs are tables and they both have row names, then their row names must be the same. However, the row names in each input can be in a different order.

• If both inputs are timetables, then their row times must be the same. However, the row times in each input can be in a different order.

Data Types: `single` | `double` | `int8` | `int16` | `int32` | `int64` | `uint8` | `uint16` | `uint32` | `uint64` | `logical` | `char` | `string` | `categorical` | `datetime` | `duration` | `table` | `timetable`
Complex Number Support: Yes

## Version History

Introduced before R2006a

expand all