# randn

randn([rng], [dims...])

Generate a normally-distributed random number with mean 0 and standard deviation 1. Optionally generate an array of normally-distributed random numbers.

## Examples

``````julia> randn(3)
3-element Array{Float64,1}:
0.886264
0.951379
0.189251
julia> randn(1,1)
1x1 Array{Float64,2}:
-1.10013``````
``````julia> randn(10^1)
10-element Array{Float64,1}:
-0.582411
0.6569
-0.364627
-0.664332
2.31059
-1.29415
-0.324598
0.866415
0.199852
0.350528``````
``````julia> randn(10^2)
100-element Array{Float64,1}:
-0.564138
-0.290903
2.34801
1.15471
-1.96972
0.232324
-0.656563
-2.44173
1.20195
0.993468
0.867964
0.032737
0.33407
?
0.727052
0.984324
-0.627767
0.252516
0.382487
-0.5192
0.985186
0.322768
-0.506415
-0.994221
1.0927
-0.343862``````
1. Generate a single normally-distributed random number:

``````julia> randn()
0.1950316385222502``````

This example generates a single random number from a standard normal distribution.

2. Generate an array of normally-distributed random numbers:

``````julia> randn(3)
3-element Array{Float64,1}:
-0.19044704142415453
-0.4862101494629707
-0.16060936031308463``````

It generates an array of three random numbers from a standard normal distribution.

3. Specify dimensions for a multidimensional array:

``````julia> randn(2, 3)
2×3 Array{Float64,2}:
-0.821126  -0.130874  -0.366167
-0.158623   1.30861    0.334751``````

In this example, a 2x3 array of random numbers from a standard normal distribution is generated.

4. Specify a custom random number generator:
``````julia> rng = MersenneTwister(1234);
julia> randn(rng)
-0.20497626684002162``````

It generates a single random number using a specific random number generator, `MersenneTwister` in this case.

Common mistake example:

``````julia> randn(0)
ERROR: ArgumentError: The dims argument must be an integer or a tuple of integers``````

In this example, an incorrect argument is provided as the dimensions. The `dims` argument should be an integer or a tuple of integers representing the dimensions of the desired output array.