I learn to program in Julia language.
I want to test which color is better, so I use the following code:
using Plots
x = 1:10; y = rand(10,2);
for i in [0 0.1 0.2]
plot(x,y, seriestype=:scatter,background_color=RGB(0.4,0.8,i))
end
How, nothing show.
Can anyone tell me how to generate plot with loop?
P.S.
I have tried another way,
[plot(x,y, seriestype=:scatter,background_color=RGB(0.4,0.8,i)) for i in 0:0.1:1]
Nothing happened with above code.
The following code does not work either:
map(i->plot(x,y, seriestype=:scatter,background_color=RGB(0.4,0.8,i)), [0 0.1 0.2])
In a script plot is not shown unless you use display function to show it (see section Plotting in scripts here http://docs.juliaplots.org/latest/tutorial/).
You have several options here. This one is the simplest:
for i in [0 0.1 0.2]
display(plot(x,y, seriestype=:scatter,background_color=RGB(0.4,0.8,i)))
sleep(1)
end
It will plot your figures in a sequence. I use sleep(1) to make Julia pause between plotting.
Otherwise you can do:
p = [plot(x,y, seriestype=:scatter,background_color=RGB(0.4,0.8,i)) for i in 0:0.1:1]
and then plot your figures from Julia REPL like this:
julia> p[5]
will plot fifth figure. Now you do not have to use display because in REPL it will be invoked anyway as I did not use ; at the end of the line. You could write display(p[5]) to get the same effect.
Finally you can consider saving the figures to PNG file and inspecting them later. You can do it either using p array defined above like this:
foreach(i -> savefig(p[i], "fig$i.png"), eachindex(p))
or in a loop like this:
for i in [0 0.1 0.2]
p = plot(x,y, seriestype=:scatter,background_color=RGB(0.4,0.8,i))
savefig(p, "fig$i.png)
end
Related
Julia has the delightful ability to generate plots constructed from Unicode symbols which are printed directly to the command line in a very straightforward way. For example, the following code generates a Unicode plot of a sine function directly to the command line:
using Plots
unicodeplots();
x = [0:0.1:2*pi;];
y = sin.(x);
plot(x,y)
I would like to try to find a way to create an animated plot of this form directly on the command line. Ideally, I would like to generate a single plot in Unicode that is ``updated" in such a way that it appears animated.
However, although printing hundreds of distinct frames to the command line is naturally less appealing, such a solution is acceptable if it ``looks" like an animation. Another less acceptable solution is to print such Unicode plots into a gif in a way that is consistent for all platforms; attempts to do any of this involving jury-rigging #animate and #gif have largely failed, since either function cannot even print Unicode plots to a file in the Windows form of Julia.
UPDATE: Here is an example of code that generates an "animation" in the command line that is not really acceptable, which simply plots each distinct frame followed by "spacing" in the command line provided by a special Unicode character (tip provided by niczky12):
using Plots
unicodeplots();
n = 100;
x = [0:0.1:4*pi;];
for i = 1:30
y = sin.(x .+ (i/2));
plot(x, y, show=true, xlims = (0,4*pi), ylims = (-1,1))
sleep(0.01)
println("\33[2J")
end
A slight improvement might be this:
let
print("\33[2J")
for i in 1:30
println("\33[H")
y = sin.(x .+ (i/2));
plot(x, y, show=true, xlims = (0,4*pi), ylims = (-1,1))
sleep(0.01)
end
end
I want to write ALOHA simulation but I plot this picture only G=0 1 2 3.What I need to add?
using Plots
A = []
for G in 0.0:3.0
S = G*ℯ^(-2G)
push!(A, S)
end
println(A)
plot(A)
Your code could be written like this, is this what you need?:
using Plots
G=0.0:0.01:3.0
A= G.*ℯ.^(-2G)
plot(G,A)
Another option is
using Plots
plot(x -> x * exp(-2x), 0, 3)
which also gives
I would like to create a stacked area chart, similar to this for example, in Julia using Plots.
I know / suppose that you can do this if you directly use the Gadfly or PyPlot backends in Julia, but I was wondering if there was a recipe for this. If not, how can you contribute to the Plots Recipes? Would be a useful addition.
There's a recipe for something similar in
https://docs.juliaplots.org/latest/examples/pgfplots/#portfolio-composition-maps
For some reason the thumbnail looks broken now though (but the code works).
The exact plot in the matlab example can be produced by
plot(cumsum(Y, dims = 2)[:,end:-1:1], fill = 0, lc = :black)
As a recipe that would look like
#userplot AreaChart
#recipe function f(a::AreaChart)
fillto --> 0
linecolor --> :black
seriestype --> :path
cumsum(a.args[1], dims = 2)[:,end:-1:1]
end
If you want to contribute a recipe to Plots you can open a pull request on Plots, or, eg. on StatsPlots - there's a good description of contributing here: https://docs.juliaplots.org/latest/contributing/
It's a bit of reading, but very generally useful as an introduction to contributing to Julia packages.
You can read this thread in the Julia discourse forum where the question is developed in deep.
One solution posted there using Plots is :
# a simple "recipe" for Plots.jl to get stacked area plots
# usage: stackedarea(xvector, datamatrix, plotsoptions)
#recipe function f(pc::StackedArea)
x, y = pc.args
n = length(x)
y = cumsum(y, dims=2)
seriestype := :shape
# create a filled polygon for each item
for c=1:size(y,2)
sx = vcat(x, reverse(x))
sy = vcat(y[:,c], c==1 ? zeros(n) : reverse(y[:,c-1]))
#series (sx, sy)
end
end
a = [1,1,1,1.5,2,3]
b = [0.5,0.6,0.4,0.3,0.3,0.2]
c = [2,1.8,2.2,3.3,2.5,1.8]
sNames = ["a","b","c"]
x = [2001,2002,2003,2004,2005,2006]
plotly()
stackedarea(x, [a b c], labels=reshape(sNames, (1,3)))
(by user NiclasMattsson)
Other ways presented there include using the VegaLite.jl package.
I am working with a large number of observations and to really get to know it I want to do histograms using Plots.jl
My question is how I can do multiple histograms in one plot as this would be really handy. I have tried multiple things already, but I am a bit confused with the different plotting sources in julia (plots.jl, pyplot, gadfly,...).
I don't know if it would help for me to post some of my code, as this is a more general question. But I am happy to post it, if needed.
There is an example that does just this:
using Plots
pyplot()
n = 100
x1, x2 = rand(n), 3rand(n)
# see issue #186... this is the standard histogram call
# our goal is to use the same edges for both series
histogram(Any[x1, x2], line=(3,0.2,:green), fillcolor=[:red :black], fillalpha=0.2)
I looked for "histograms" in the Plots.jl repo, found this related issue and followed the links to the example.
With Plots, there are two possibilities to show multiple series in one plot:
First, you can use a matrix, where each column constitutes a separate series:
a, b, c = randn(100), randn(100), randn(100)
histogram([a b c])
Here, hcat is used to concatenate the vectors (note the spaces instead of commas).
This is equivalent to
histogram(randn(100,3))
You can apply options to the individual series using a row matrix:
histogram([a b c], label = ["a" "b" "c"])
(Again, note the spaces instead of commas)
Second, you can use plot! and its variants to update a previous plot:
histogram(a) # creates a new plot
histogram!(b) # updates the previous plot
histogram!(c) # updates the previous plot
Alternatively, you can specify which plot to update:
p = histogram(a) # creates a new plot p
histogram(b) # creates an independent new plot
histogram!(p, c) # updates plot p
This is useful if you have several subplots.
Edit:
Following Felipe Lema's links, you can implement a recipe for histograms that share the edges:
using StatsBase
using PlotRecipes
function calcbins(a, bins::Integer)
lo, hi = extrema(a)
StatsBase.histrange(lo, hi, bins) # nice edges
end
calcbins(a, bins::AbstractVector) = bins
#userplot GroupHist
#recipe function f(h::GroupHist; bins = 30)
args = h.args
length(args) == 1 || error("GroupHist should be given one argument")
bins = calcbins(args[1], bins)
seriestype := :bar
bins, mapslices(col -> fit(Histogram, col, bins).weights, args[1], 1)
end
grouphist(randn(100,3))
Edit 2:
Because it is faster, I changed the recipe to use StatsBase.fit for creating the histogram.
I am using a package(LightGraphs.jl) in Julia, and it has a predefined histogram method that creates the degree distribution of a network g.
deg_hist = degree_histogram(g)
I want to make a plot of this but i am new to plotting in Julia. The object returned is a StatsBase.Histogram which has the following as its inner fields:
StatsBase.Histogram{Int64,1,Tuple{FloatRange{Float64}}}
edges: 0.0:500.0:6000.0
weights: [79143,57,32,17,13,4,4,3,3,2,1,1]
closed: right
Can you help me how I can make use of this object to plot the histogram?
I thought this was already implemented, but I just added the recipe to StatPlots. If you check out master, you'll be able to do:
julia> using StatPlots, LightGraphs
julia> g = Graph(100,200);
julia> plot(degree_histogram(g))
For reference, the associated recipe that I added to StatPlots:
#recipe function f(h::StatsBase.Histogram)
seriestype := :histogram
h.edges[1], h.weights
end
Use the histogram fields .edges and .weights to plot it e.g.
using PyPlot, StatsBase
a = rand(1000); # generate something to plot
test_hist = fit(Histogram, a)
# line plot
plot(test_hist.edges[1][2:end], test_hist.weights)
# bar plot
bar(0:length(test_hist.weights)-1, test_hist.weights)
xticks(0:length(test_hist.weights), test_hist.edges[1])
or you could create/extend a plotting function adding a method like so:
function myplot(x::StatsBase.Histogram)
... # your code here
end
Then you will be able to call your plotting functions directly on the histogram object.