Julia Plotting Cheat Sheet
Tags: julialang, linearalgebra, datascience, julia
Published: 2023-04-14 20:08:53

This cheat sheet provides an overview of the most commonly used plotting functions and attributes in Julia using the popular plotting library Plots.jl. To get started, make sure you have the Plots package installed by running:

```
using Pkg
Pkg.add("Plots")
```

Then load the Plots library by running:

```
using Plots
```

## Basic Plotting Functions

1. Line plot:

```
function linePlot()
    x = 1:0.1:10
    y = cos.(x)
    plot(x, y, label="cos(x)")
end
```

![Line plot in Julia](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/u5b1b2vrolv51973mfhg.png)



2. [Scatter plot](https://docs.juliaplots.org/latest/generated/unitfulext_examples/#Scatter-plots):

```
function scatterPlot()
    x = 1:0.1:10
    y = cos.(x)
    scatter(x, y, label="cos(x)")
end
```

![Scatter plot in Julia](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/59r8qpym3wismgeyur4x.png)


3. [Bar plot](url):
```
function barPlot()
    x = 1:0.1:10
    y = cos.(x)
    bar(x, y, label="cos(x)")
end
```

![Bar plot in Julia](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ljaqy0a5smpltmo6xwrh.png)



4. Histogram:
```
function histogramPlot()
    x = 1:0.1:10
    y = cos.(x)
    histogram(x, y, label="cos(x)")
end
```
![Histogram in Julia](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/v65o5pg5odkantqhr49q.png)

5. Box plot:

```
using StatsPlots
function boxPlot()
    x = 1:0.1:10
    y = cos.(x)
    boxplot(x, y, label="cos(x)")
end
```

![Boxplot in Julia](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/jfcbx99kpczro6v7wf9r.png)


6. [Heatmap](https://docs.juliaplots.org/latest/generated/unitfulext_examples/#Heatmaps):

```
function heatmapPlot()
    data = rand(21, 100)
    heatmap(1:size(data, 1),
        1:size(data, 2), data,
        c=cgrad([:blue, :white, :red, :yellow]),
    )
end
```

![Heatmap in Julia](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/h48i4u6pydcephhx456i.png)


7. 3D plot:

```
function plot3D()
    x = 1:0.1:10
    y = cos.(x)
    z = sin.(x)
    plot3d(x, y, z, label="cos(x)")
end
```

![3D Plot in Julia](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/i1fasgmcbxbdnsl7ndv6.png)


## Common Plot Attributes
### Title, labels, and legend

- `title`: Plot title
- `xlabel`: x-axis label
- `ylabel`: y-axis label
- `zlabel`: z-axis label (for 3D plots)
- `legend`: Legend position 
  - :topleft
  - :topright
  - :bottomleft
  - :bottomright
  - :outertopleft
  - :outertopright
  - :outerbottomleft
  - :outerbottomright
  - :best
  - :none

Example:

```
plot(x, y, title="My Line Plot", xlabel="x-axis", ylabel="y-axis", legend=:topleft)
```
### Line style
- `ls`: Line style
  - :solid
  - :dash
  - :dot
  - :dashdot
  - :dashdotdot
- `lw`: Line width

Example:

```
plot(x, y, ls=:dash, lw=2)
```
### Marker style

![Graph showing all possible marker shapes](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/8jxq5abdn6i76gg22os2.png)


- `m`: Marker shape
  - :circle
  - :diamond
  - :cross
  - :xcross
  - :utriangle
  - :dtriangle
  - :rtriangle
  - :ltriangle
  - :pentagon
  - :hexagon
  - :heptagon
  - :octagon 
  - :star4
  - :star5
  - :star6
  - :star7
  - :star8
  - :vline
  - :hline
  - :none)
- `ms`: Marker size
- `mc`: Marker color

Example:

```
scatter(x, y, m=:diamond, ms=5, mc=:red)
```
### Colors and styles
- `c`: Line or marker color
- `fillcolor`: Fill color (for bar plots, histograms, etc.)
- `fillalpha`: Fill transparency
- `alpha`: Line or marker transparency

Example:

```
bar(x, y, c=:blue, fillcolor=:orange, fillalpha=0.5, alpha=0.8)
```
### Axis limits and scales
- `xlims`: x-axis limits
- `ylims`: y-axis limits
- `zlims`: z-axis limits (for 3D plots)
- `xscale`: x-axis scale
  - :linear
  - :log10
  - :log2
  - :log
- `yscale`: y-axis scale
  - :linear
  - :log10
  - :log2
  - :log
- `zscale`: z-axis scale (for 3D plots)

Example:

```
plot(x, y, xlims=(0,10), ylims=(-1, 1), xscale=:log10, yscale=:linear)
```
### Grid, Ticks, and Background
- `grid`: Grid visibility (`:on`, `:off`)
- `gridcolor`: Grid color
- `gridalpha`: Grid transparency
- `gridstyle`: Grid style
  - :solid
  - :dash
  - :dot
  - :dashdot
  - :dashdotdot
- `xticks`: x-axis tick marks (vector of tick positions, `:auto`, `:none`)
- `yticks`: y-axis tick marks (vector of tick positions, `:auto`, `:none`)
- `zticks`: z-axis tick marks (for 3D plots)
- `tickfontsize`: Tick label font size
- `background_color`: Plot background color
- `foreground_color`: Plot foreground color

Example:

```
plot(x, y, grid=:on, gridcolor=:grey, gridalpha=0.5, gridstyle=:dash, xticks=0:2:10, yticks=:auto, tickfontsize=12, background_color=:white, foreground_color=:black)
```

## Subplots and Layouts
layout: Subplot layout (tuple of rows and columns, e.g. (2, 3) for 2 rows and 3 columns)
title: Titles for each subplot (vector of strings)
Example:

```
plot(x, [y1, y2, y3, y4, y5, y6], layout=(2, 3), title=["Plot 1" "Plot 2" "Plot 3" "Plot 4" "Plot 5" "Plot 6"])
```

# Plots in VS Code
If you are using VS Code and Julia, each new plot you create will appear in the "Plot Navigator" on the Julia tab of your workspace.

![Julia Plot Navigator](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/x6xb8uky6dusmwbfzctm.png)

With a plot selected, you can choose to either save or delete it using the icons in the upper right portion of the screen.

![VS Code plot options](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/oj645v12tuch80t3n635.png)


# Conclusion
This is a brief overview of the most commonly used plotting functions and attributes in Julia using the Plots.jl library. For a more comprehensive overview, refer to the official [Plots documentation](https://docs.juliaplots.org/latest/) and explore the [Plots Tutorial](https://docs.juliaplots.org/latest/tutorial/#tutorial)

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