mean

mean(v[, region])

Compute the mean of whole array `v`, or optionally along the dimensions in `region`. Note: Julia does not ignore `NaN` values in the computation. For applications requiring the handling of missing data, the `DataArray` package is recommended.

Examples

``````julia> xsum = rand(5)
mean(xsum)
0.38190307541901564``````
``````julia> A = rand(3)
3-element Array{Float64,1}:
0.443922
0.79404
0.959896
julia> mean(A)
0.6369315513562785``````
1. Compute the mean of a 1-dimensional array:

``````julia> v = [1, 2, 3, 4, 5];
julia> mean(v)
3.0``````

This example calculates the mean of the array `v`, which is 3.0.

2. Compute the mean along a specific dimension of a multi-dimensional array:

``````julia> A = [1 2 3; 4 5 6; 7 8 9];
julia> mean(A, dims = 1)
1×3 Array{Float64,2}:
4.0  5.0  6.0``````

Here, the `mean` function is used to calculate the mean along the first dimension (columns) of the 2-dimensional array `A`. The result is a 1x3 array with the means of each column.

3. Compute the mean along multiple dimensions:
``````julia> B = [1 2 3; 4 5 6; 7 8 9; 10 11 12];
julia> mean(B, dims = (1, 2))
1-element Array{Float64,1}:
6.5``````

In this example, the `mean` function calculates the mean along both dimensions of the 2-dimensional array `B`. The result is a 1-element array with the overall mean of the array.

Common mistake example:

``````julia> v = []
julia> mean(v)
ERROR: MethodError: no method matching mean(::Array{Any,1})``````

Here, an empty array `v` is provided to the `mean` function, which results in a `MethodError` because Julia cannot determine the appropriate method to use. Make sure to provide a non-empty array to calculate the mean accurately.

See Also

cummax, eigmax, findmax, hist, hist!, hist2d, hist2d!, histrange, indmax, maxabs, maxabs!, maximum!, mean, mean!, median, median!, minabs, minabs!, minimum!, minmax, quantile!, realmax, std, stdm,

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