# wblrnd

Weibull random numbers

## Syntax

``r = wblrnd(a,b)``
``r = wblrnd(a,b,sz1,...,szN)``
``r = wblrnd(a,b,sz)``

## Description

example

````r = wblrnd(a,b)` generates a random number from the Weibull distribution with scale `a` and shape `b`. ```

example

````r = wblrnd(a,b,sz1,...,szN)` generates an array of random numbers from the Weibull distribution, where `sz1,...,szN` indicates the size of each dimension. ```

example

````r = wblrnd(a,b,sz)` generates an array of random numbers from the Weibull distribution where size vector `sz` specifies `size(r)`. ```

## Examples

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Generate a single random number from the Weibull distribution with scale `4` and shape `3`.

`r = wblrnd(4,3)`
```r = 2.3582 ```

Generate a 1-by-5 array of random numbers drawn from the Weibull distributions with scale `3` and shape values `1` through `5`.

```a1 = 3; b1 = 1:5; r1 = wblrnd(a1,b1)```
```r1 = 1×5 0.6147 0.9437 3.8195 1.6459 2.5666 ```

If you specify array dimensions, they must match the dimensions of `a` and `b` after any scalar expansion.

Generate a 1-by-6 array of random numbers drawn from the Weibull distributions with scale values `1` through `6` and shape values `5` through `10`, respectively.

```a2 = 1:6; b2 = 5:10; sz1 = 1; sz2 = 6; r2 = wblrnd(a2,b2,sz1,sz2)```
```r2 = 1×6 1.1841 2.0836 2.7912 2.7026 3.4531 6.3799 ```

Generate a 2-by-3 array of random numbers from the Weibull distribution with scale `4` and shape `5`.

```sz = [2 3]; r3 = wblrnd(4,5,sz)```
```r3 = 2×3 1.9817 3.7486 4.5729 2.1395 2.9624 3.8841 ```

## Input Arguments

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Scale parameter of the Weibull distribution, specified as a positive scalar value or an array of positive scalar values.

To generate random numbers from multiple distributions, specify `a` and `b` using arrays. If either or both of the input arguments `a` and `b` are arrays, then the array sizes must be the same. In this case, `wblrnd` expands each scalar input into a constant array of the same size as the array inputs. Each element in `r` is the random number generated from the distribution specified by the corresponding elements in `a` and `b`.

Example: `[1 2 3 5]`

Data Types: `single` | `double`

Shape parameter of the Weibull distribution, specified as a positive scalar value or an array of positive scalar values.

To generate random numbers from multiple distributions, specify `a` and `b` using arrays. If either or both of the input arguments `a` and `b` are arrays, then the array sizes must be the same. In this case, `wblrnd` expands each scalar input into a constant array of the same size as the array inputs. Each element in `r` is the random number generated from the distribution specified by the corresponding elements in `a` and `b`.

Example: `[1 1 2 2]`

Data Types: `single` | `double`

Size of each dimension, specified as separate arguments of integers.

If `a` and `b` are arrays, then the specified dimensions `sz1,...,szN` must match the dimensions of `a` and `b`. The default values of `sz1,...,szN` are the dimensions of `a` and `b`.

• If you specify a single value `sz1`, then `r` is a square matrix of size `sz1`-by-`sz1`.

• If the size of any dimension is `0` or negative, then `r` is an empty array.

• Beyond the second dimension, `wblrnd` ignores trailing dimensions with a size of `1`. For example, `wblrnd``(2,5,3,1,1,1)` produces a 3-by-1 vector of random numbers from the distribution with scale `2` and shape `5`.

Example: `3,5`

Data Types: `single` | `double`

Size of each dimension, specified as a row vector of integers.

If `a` and `b` are arrays, then the specified dimensions `sz` must match the dimensions of `a` and `b`. The default values of `sz` are the dimensions of `a` and `b`.

• If you specify a single value [`sz1`], then `r` is a square matrix of size `sz1`-by-`sz1`.

• If the size of any dimension is `0` or negative, then `r` is an empty array.

• Beyond the second dimension, `wblrnd` ignores trailing dimensions with a size of `1`. For example, `wblrnd``(2,5,[3 1 1 1])` produces a 3-by-1 vector of random numbers from the distribution with scale `2` and shape `5`.

Example: `[3 5]`

Data Types: `single` | `double`

## Output Arguments

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Weibull random numbers, returned as a scalar value or an array of scalar values with the dimensions specified by `sz1,...,szN` or `sz`. Each element in `r` is the random number generated from the distribution specified by the corresponding elements in `a` and `b`.

## Alternative Functionality

• `wblrnd` is a function specific to the Weibull distribution. Statistics and Machine Learning Toolbox™ also offers the generic function `random`, which supports various probability distributions. To use `random`, specify the probability distribution name and its parameters. Note that the distribution-specific function `wblrnd` is faster than the generic function `random`.

• To generate random numbers interactively, use `randtool`, a user interface for random number generation.