Using packages

Introduction to Julia

James Fulton

Climate informatics researcher

Packages

A collection of Julia files from which you can import
Popular packages include
- Statistics.jl - calculating descriptive statistics
- DataFrames.jl - storing and manipulating tabular data
- CSV.jl - loading and saving CSV data
- Plots.jl - creating visualizations
Thousands more packages exist
Some lists of packages found here:
- https://julialang.org/packages

Installing packages

import MyPackage

 | Package MyPackage not found, but a package named MyPackage is available from a registry. 
 | Install package?
 |   (@v1.7) pkg> add MyPackage 
 |_ (y/n) [y]:

Importing packages

import Statistics


m = Statistics.mean([1,2,3])
println(m)

2.0

m = mean([1,2,3])
println(m)

ERROR: UndefVarError: mean not defined

using Statistics


m = Statistics.mean([1,2,3])
println(m)

2.0

m = mean([1,2,3])
println(m)

2.0

Importing packages

import Statistics as sts


m = sts.mean([1,2,3])
println(m)

2.0

using Statistics


m = Statistics.mean([1,2,3])
println(m)

2.0

m = mean([1,2,3])
println(m)

2.0

The Statistics package

mean() - Calculate mean of array
median() - Calculate median value of array
std() - Calculate standard deviation of array values
var() - Calculate variance of array values

mean_x = Statistics.mean(x_arr)

median_x = Statistics.median(x_arr)

std_x = Statistics.std(x_arr)

var_x = Statistics.var(x_arr)

Let's practice!

Introduction to Julia