Polar Charts in Julia

Polar chart

A polar chart represents data along radial and angular axes. Using the scatterpolar trace type, it is possible to represent polar data as scatter markers by setting mode="markers" and polar lines by setting mode="lines".

The radial and angular coordinates are given with the r and theta arguments of scatterpolar. In the example below the theta data are categorical, but numerical data are possible too and the most common case.

using PlotlyJS, CSV, DataFrames df = dataset(DataFrame, "wind") plot(scatterpolar(df, r=:frequency, theta=:direction, mode="markers"))

The "strength" column corresponds to strength categories of the wind, and there is a frequency value for each direction and strength. Below we use the strength column to encode the color of the markers.

using PlotlyJS, CSV, DataFrames df = dataset(DataFrame, "wind") plot(scatterpolar( df, r=:frequency, theta=:direction, color=:strength, marker=attr(size=:frequency, sizeref=0.05), mode="markers" )) 

For a line polar plot, use mode="lines":

using PlotlyJS, CSV, DataFrames df = dataset(DataFrame, "wind") plot(scatterpolar( df, r=:frequency, theta=:direction, color=:strength, marker=attr(size=:frequency, sizeref=0.05), mode="lines" ))

You can plot less than a whole circle by setting the polar_sector argument on the Layout. You can also control the direction using polar_angularaxis_direction:

using PlotlyJS plot( scatterpolar(r=0:10:90, theta=0:10:90, mode="markerss",), Layout(polar=attr(angularaxis_direction="counterclockwise", sector=(0, 90))) )

Line Polar Chart

using PlotlyJS, CSV, DataFrames, HTTP read_remote_csv(url) = DataFrame(CSV.File(HTTP.get(url).body)) df = read_remote_csv("https://raw.githubusercontent.com/plotly/datasets/master/polar_dataset.csv") plot([ scatterpolar(df, r=:x1, theta=:y, mode="lines", name="Figure 8"), scatterpolar(df, r=:x2, theta=:y, mode="lines", name="Cardioid"), scatterpolar(df, r=:x3, theta=:y, mode="lines", name="Hypercardioid"), ], Layout(title="Mic Patterns"))

Polar Bar Chart

a.k.a matplotlib logo in a few lines of code

using PlotlyJS plot( barpolar( r=[3.5, 1.5, 2.5, 4.5, 4.5, 4, 3], theta=[65, 15, 210, 110, 312.5, 180, 270], width=[20,15,10,20,15,30,15,], marker_color=["#E4FF87", "#709BFF", "#709BFF", "#FFAA70", "#FFAA70", "#FFDF70", "#B6FFB4"], marker_line_color="black", marker_line_width=2, opacity=0.8 ), Layout(polar = attr( radialaxis = attr(range=[0, 5], showticklabels=false, ticks=""), angularaxis = attr(showticklabels=false, ticks="") )) )

Categorical Polar Chart

using PlotlyJS p = make_subplots(rows=2, cols=2, specs=fill(Spec(kind="polar"), 2, 2)) add_trace!(p, row=1, col=1, scatterpolar( name = "angular categories", r = [5, 4, 2, 4, 5], theta = ["a", "b", "c", "d", "a"], )) add_trace!(p, row=1, col=2, scatterpolar( name = "radial categories", r = ["a", "b", "c", "d", "b", "f", "a"], theta = [1, 4, 2, 1.5, 1.5, 6, 5], thetaunit = "radians", )) add_trace!(p, row=2, col=1, scatterpolar( name = "angular categories (w/ categoryarray)", r = [5, 4, 2, 4, 5], theta = ["a", "b", "c", "d", "a"], )) add_trace!(p, row=2, col=2, scatterpolar( name = "radial categories (w/ category descending)", r = ["a", "b", "c", "d", "b", "f", "a", "a"], theta = [45, 90, 180, 200, 300, 15, 20, 45], )) relayout!(p, polar=attr( radialaxis_angle=-45, angularaxis=attr( direction="clockwise", period=6 ) ), polar2=attr( radialaxis=attr( angle=180, tickangle=-180 # so that tick labels are not upside down ) ), polar3=attr( sector=[80, 400], radialaxis_angle=-45, angularaxis_categoryarray=["d", "a", "c", "b"] ), polar4=attr( radialaxis_categoryorder="category descending", angularaxis=attr( thetaunit="radians", dtick=0.3141592653589793 ) ) )

nothing

Polar Chart Sector

using PlotlyJS p = make_subplots(rows=1, cols=2, specs=fill(Spec(kind="polar"), 1, 2)) make_trace() = scatterpolar( r=[1,2,3,4,5], theta=[0,90,180,360,0], mode="lines+markers", line_color="magenta", marker=attr( color="royalblue", symbol="square", size=8 ) ) add_trace!(p, make_trace(), row=1, col=1) add_trace!(p, make_trace(), row=1, col=2) # The sector is [0, 360] by default, we update it for the first plot only # setting parameters for the second plot would be polar2=... relayout!(p, polar_sector=[150, 210]) p

Polar Chart Directions

using PlotlyJS p = make_subplots(rows=1, cols=2, specs=fill(Spec(kind="polar"), 1, 2)) r = [1,2,3,4,5] theta = [0,90,180,360,0] make_trace() = scatterpolar( r=[1,2,3,4,5], theta=[0,90,180,360,0], mode="lines+markers", line_color="indianred", marker=attr( color="lightslategray", symbol="square", size=8 ) ) add_trace!(p, make_trace(), row=1, col=1) add_trace!(p, make_trace(), row=1, col=2) relayout!(p, showlegend=false, polar=attr( radialaxis_tickfont_size=8, angularaxis=attr( tickfont_size=8, rotation=90, # start position of angular axis direction="counterclockwise" ) ), polar2=attr( radialaxis_tickfont_size=8, angularaxis=attr( tickfont_size=8, rotation=90, direction="clockwise" ), ) ) p

Webgl Polar Chart

The scatterpolargl trace uses the WebGL plotting engine for GPU-accelerated rendering.

using PlotlyJS, CSV, DataFrames, HTTP read_remote_csv(url) = DataFrame(CSV.File(HTTP.get(url).body)) df = read_remote_csv("https://raw.githubusercontent.com/plotly/datasets/master/hobbs-pearson-trials.csv") plot( [ scatterpolargl( df; marker=attr(size=15, color="mediumseagreen"), mode="markers", r=:trial_1_r,theta=:trial_1_theta, name="Trial 1", ), scatterpolargl( df; marker=attr(size=20, color="darkorange"), mode="markers", r=:trial_2_r,theta=:trial_2_theta, name="Trial 2", ), scatterpolargl( df; marker=attr(size=12, color="mediumpurple"), mode="markers", r=:trial_3_r,theta=:trial_3_theta, name="Trial 3", ), scatterpolargl( df; marker=attr(size=22, color = "magenta"), mode="markers", r=:trial_4_r,theta=:trial_4_theta, name="Trial 4", ), scatterpolargl( df; marker=attr(size=19, color="limegreen"), mode="markers", r=:trial_5_r,theta=:trial_5_theta, name="Trial 3", ), scatterpolargl( df; marker=attr(size=10, color = "gold"), mode="markers", r=:trial_6_r,theta=:trial_6_theta, name="Trial 4", ), ], Layout( title="Hobbs-Pearson Trials", font_size=15, showlegend=false, polar=attr( bgcolor="rgb(223, 223, 223)", angularaxis=attr(linewidth=3, showline=true, linecolor="black"), radialaxis=attr( side="counterclockwise", showline=true, linewidth=2, gridcolor="white", gridwidth=2, ) ), paper_bgcolor="rgb(223, 223, 223)" ) )

Reference

See https://plotly.com/julia/reference/scatterpolar/ for more information and chart attribute options!