Line plot in Julia shows a weird line... is this a bug? - julia

I am trying to plot two series (each has 2,000 points) using Plots.plot function in Julia 1.7.3.
When drawing the line plot, Julia displays a weird line that goes from an end of the line to the other across the plane as above. There is a strange orange diagonal, and there's no data point on that line. Does anyone know if this is a bug, or is there any error with my code?
Em_mu = [a_grid.+Es[1] res.mu[:,1]]
Unem_mu = [a_grid.+Es[2] res.mu[:,2]]
Em_dat = DataFrame(wealth = Em_mu[:,1], density1 = Em_mu[:,2])
Unem_dat = DataFrame(wealth = Unem_mu[:,1], density2 = Unem_mu[:,2])
wealth_mat = outerjoin(Em_dat, Unem_dat, on=:wealth)
replace!(wealth_mat.density1, missing => 0)
replace!(wealth_mat.density2, missing => 0)
disallowmissing!(wealth_mat)
wealth_mat = Matrix(wealth_mat)
Plots.plot(wealth_mat[:,1], wealth_mat[:,2:3], title = "Distribution")

It looks like your second series is not sorted by its x values. The line plot connects data points with a line so if it's not sorted you get weird lines like that.

Related

How to plot the function 4(x)^2 = ((y)^2/(1-y))?

I want to plot the function
4(x)^2 = ((y)^2/(1-y));
how can I plot this?
--> 4*(x) = ((y^2)*(1-y)^-1)^0.5;
4*(x) = ((y^2)*(1-y)^-1)^0.5;
^^
Error: syntax error, unexpected =, expecting end of file
Since Scilab 6.1.0, plotimplicit() does it:
plotimplicit "4*x^2 = y^2/(1-y)"
xgrid()
Can't do more simple. Result:
Well, you have to first create a function and for that you have to express one variable in terms of the other.
function x = f(y)
x = (((y^2)*(1-y)^-1)^0.5)/4;
endfunciton
Then you need to generate the input data (i.e, the points at which you want to evaluate the function)
ydata = linspace(1, 10)
Now you push your input point through the function to get your output points
xdata = f(ydata)
Then, you can plot the pairs of x and y using:
plot(xdata, ydata)
Or even easier, without the intermediate step of generating the output data, you can simply do:
plot(f(ydata), ydata)
BTW. I find it strange that the function you are trying to plot is x in terms of y, usually, x is the input variable, but I hope you know what you are trying to accomplish.
Reference: https://www.scilab.org/tutorials/getting-started/plotting
Take care that y must be in [-inf 1[
y=linspace(-10 ,1.00001,1000);
x = sqrt(y^2./(1-y))/4;
clf; plot(y,x),plot(y,-x)
If x is a solution -x is also solution

Julia Plotting: delete and modify existing lines

Two questions in one: Given a line plotted in Julia, how can I
delete it from the plot and legend (without clearing the whole plot)
change its properties (such as color, thickness, opacity)
As a concrete example in the code below, how can I 1. delete previous regression lines OR 2. change their opacity to 0.1?
using Plots; gr()
f = x->.3x+.2
g = x->f(x)+.2*randn()
x = rand(2)
y = g.(x)
plt = scatter(x,y,c=:orange)
plot!(0:.1:1, f, ylim=(0,1), c=:green, alpha=.3, linewidth=10)
anim = Animation()
for i=1:200
r = rand()
x_new, y_new = r, g(r)
push!(plt, x_new, y_new)
push!(x, x_new)
push!(y, y_new)
A = hcat(fill(1., size(x)), x)
coefs = A\y
plot!(0:.1:1, x->coefs[2]*x+coefs[1], c=:blue) # plot new regression line
# 1. delete previous line
# 2. set alpha of previous line to .1
frame(anim)
end
gif(anim, "regression.gif", fps=5)
I tried combinations of delete, pop! and remove but without success.
A related question in Python can be found here: How to remove lines in a Matplotlib plot
Here is a fun and illustrative example of how you can use pop!() to undo plotting in Julia using Makie. Note that you will see this goes back in the reverse order that everything was plotted (think, like adding and removing from a stack), so deleteat!(scene.plots, ind) will still be necessary to remove a plot at a specific index.
using Makie
x = range(0, stop = 2pi, length = 80)
f1(x) = sin.(x)
f2(x) = exp.(-x) .* cos.(2pi*x)
y1 = f1(x)
y2 = f2(x)
scene = lines(x, y1, color = :blue)
scatter!(scene, x, y1, color = :red, markersize = 0.1)
lines!(scene, x, y2, color = :black)
scatter!(scene, x, y2, color = :green, marker = :utriangle, markersize = 0.1)
display(scene)
sleep(10)
pop!(scene.plots)
display(scene)
sleep(10)
pop!(scene.plots)
display(scene)
You can see the images above that show how the plot progressively gets undone using pop(). The key idea with respect to sleep() is that if we were not using it (and you can test this on your own by running the code with it removed), the fist and only image shown on the screen will be the final image above because of the render time.
You can see if you run this code that the window renders and then sleeps for 10 seconds (in order to give it time to render) and then uses pop!() to step back through the plot.
Docs for sleep()
I have to say that I don't know what the formal way is to accomplish them.
There is a cheating method.
plt.series_list stores all the plots (line, scatter...).
If you have 200 lines in the plot, then length(plt.series_list) will be 200.
plt.series_list[1].plotattributes returns a dictionary containing attributes for the first line(or scatter plot, depends on the order).
One of the attributes is :linealpha, and we can use it to modify the transparency of a line or let it disappear.
# your code ...
plot!(0:.1:1, x->coefs[2]*x+coefs[1], c=:blue) # plot new regression line
# modify the alpha value of the previous line
if i > 1
plt.series_list[end-1][:linealpha] = 0.1
end
# make the previous line invisible
if i > 2
plt.series_list[end-2][:linealpha] = 0.0
end
frame(anim)
# your code ...
You cannot do that with the Plots package. Even the "cheating" method in the answer by Pei Huang will end up with the whole frame getting redrawn.
You can do this with Makie, though - in fact the ability to interactively change plots was one of the reasons for creating that package (point 1 here http://makie.juliaplots.org/dev/why-makie.html)
Not sure about the other popular plotting packages for Julia.

How to plot multiple line graphs in one graph from a function that generates 3 graphs in a single command?

I am using frequencyConnectedness package in which one function plotOverall genrates 3 graphs one after another on pressing enter to continue. I need to plot all three graphs into one graph. How to do this ?
For sample data kindly use the dataset "volatilities" which comes with frequencyConnectedness package.
library(frequencyConnectedness)
data(volatilities)
bounds=(pi+0.0001,pi/3,pi/10,0)
p=list(p = 4, type = "const")
ESTIMATE<- spilloverRollingBK12(volatilities, n.ahead = 100, no.corr = F, func_est = "VAR", params_est = p, window = 100, partition = bounds)
plotOverall(ESTIMATE)
The above command generates three graphs .Basically it generates one graph for each bound as i have defined three bounds it gives three graphs . I need to plot them all in one graph . How to do this ?

Legend outside plot does not work with plotyy in Octave

I am trying to create a plot in Octave (using v4.4.1 on Windows) using plotyy and putting the legend outside the plot (because the data covers all the usable space inside the graph). The following MVCE should reproduce the issue fairly well:
% Generate some random data to reproduce the issue
data = rand(1000,10);
data(:,1:8) = data(:,1:8)-0.5;
data(:,9:10) = data(:,9:10)+30;
timedate = linspace(737310,737313,size(data,1));
data_labels={'1';'2';'3';'4';'5';'6';'7';'8';'9';'10'};
% Plot the data
figure('Name','MVCE','Position',[300 200 1000 600])
[ax,h1,h2] = plotyy(timedate,data(:,1:8),timedate,data(:,9:10));
set(h2,'Visible','on');
datetick(ax(1),'x','HH:MM:SS')
datetick(ax(2),'x','HH:MM:SS')
ylim(ax(1),[-1 1])
ylim(ax(2),[20 50])
xlabel('Date & time')
ylabel(ax(1),'Something')
ylabel(ax(2),'Something else')
title('plotyy graph with legend problem')
[hl,hlo] = legend([h1;h2],data_labels,'location','eastoutside');
grid on
This the output of the code using the gnuplot graphics toolkit:
As you can see, the legend does not go outside the plot, and the second y axis is not visible (it looks like part of the plot is actually truncated).
I have tried using the qt and fltk graphics toolkits, which give issues of their own:
With qt graphics toolkit
With fltk graphics toolkit
Can anoybody suggest a fix or at least workaround? Does the same issue also happen in MATLAB or is it Octave-specific?
EDIT
Using the suggestion in Tasos' answer, I managed to almost make it work with gnuplot:
% Plot the data
figure('Name','MVCE','Position',[300 200 1000 600])
[ax,h1,h2] = plotyy(timedate,data(:,1:8),timedate,data(:,9:10));
set(h2,'Visible','on');
datetick(ax(1),'x','HH:MM:SS')
datetick(ax(2),'x','HH:MM:SS')
ylim(ax(1),[-1 1])
ylim(ax(2),[20 50])
ax1Pos = get(ax(1), 'position');
ax2Pos = get(ax(2), 'position');
ax1Pos(3) = ax1Pos(3) * 0.73;
ax2Pos(3) = ax2Pos(3) * 0.73;
set(ax(1), 'position', ax2Pos);
set(ax(2), 'position', ax2Pos);
xlabel('Date & time')
ylabel(ax(1),'Something')
ylabel(ax(2),'Something else')
title('plotyy graph with legend problem')
[hl,hlo] = legend([h1;h2],data_labels,'location','eastoutside');
pos = get(hl,'Position');
pos(1) = 0.9;
set(hl,'Position',pos)
grid on
Which produces:
Apart from the fact that the legend overlays with the second y axis label (which it doesn't on my screen, only when printing to jpg), the problem is that Octave appears to plot two legends on top of each other for some reason: one with the first set of data attached to the first set of axes, and one with the complete set of data, for both axes right on top of the first legend. This is obviously wrong, and trying to set the Visible property of hl to off deletes both legends, not just the one.
UPDATED: deals with both legend placement and OpenGL precision affecting graph.
Regarding the problem of the legend not appearing exactly in the position you want it to, you can manually adjust the position of all axes involved in a figure, to place them exactly where you want.
Regarding the problem of OpenGL being unable to deal with the precision involved when adding small numbers to a large number, plot the graph with only the small numbers involved, and then simply adjust the xticklabels to correspond to the numbers you desire.
Full code below:
% Generate some random data to reproduce the issue
data = rand(1000,10);
data(:,1:8) = data(:,1:8)-0.5;
data(:,9:10) = data(:,9:10)+30;
t_offset = 737310;
timedate = linspace(0,3,size(data,1));
data_labels={'1';'2';'3';'4';'5';'6';'7';'8';'9';'10'};
% Plot the data
figure('Name','MVCE','Position',[300 200 1000 600])
[ax,h1,h2] = plotyy(timedate,data(:,1:8),timedate,data(:,9:10));
set(h2,'Visible','on');
ylim(ax(1),[-1 1])
ylim(ax(2),[20 50])
ylabel(ax(1),'Something')
ylabel(ax(2),'Something else')
title('plotyy graph with legend problem')
[hl,hlo] = legend([h1;h2],data_labels,'location','eastoutside');
set(hl, 'position', get(hl, 'position') .* [0.975, 1, 0.975, 1] )
grid on
ax1Pos = get(ax(1), 'position'); ax2Pos = get(ax(2), 'position');
ax1Pos(3) = ax1Pos(3) * 0.95; ax2Pos(3) = ax2Pos(3) * 0.95;
set(ax(1), 'position', ax2Pos); set(ax(2), 'position', ax2Pos);
XTicks = get(ax(1), 'xtick');
set(ax(1), 'xticklabel', datestr(XTicks + t_offset, 'HH:MM:SS'))
xlabel('Date & time')
set(ax(2), 'xtick', []);
Output:

Octave hist plot number format

I want to plot data with octaves hist() function. Unfortunately, as the numbers of the x-axis are quite large, they are displayed in scientific format, for example like 2e+007.
As this is a bit hard to read, I'd like them to be dislayed only as exponentials to the base 10, without the product or the e. So just like 10^5 for example. How can I achieve this?
When I plot data with the loglog() function, it uses the scale as I need it by default, but not for the hist().
EDIT:
To be a bit more preceise, I add some code and a picture of my plot.
NUM_SAMPLES = 10000;
% Open file.
input = fopen(filename);
x = [];
for i=[1:NUM_SAMPLES]
line = fgetl(input);
data = strsplit(line, ';');
x(end + 1) = str2num(data{1,2})/(1000);
endfor
% Close file.
fclose(input);
% Plot histogram.
figure('Position',[0,0,700,500]);
hist(x, 500);
So I just read some big numbers from my file and want to plot it with hist. Because the numbers are big, the automatically get displayed in loc scale and scientific format. Here you can see an example plot:
Unfortunately set(gca(), 'xscale', 'log'); doesn't change anything, so I think this plot is also consider log scale, but just a bad number format.
You can set the xticklabel or yticklabel manually, for example:
x = [1e7, 1e8, 1e9];
ax = gca();
set(ax, 'xticklabel', {'0','2e8','4e8','6e8','8e8','10e8'});
hist(x);
Alternatively, you can set the x axis to be in log scale:
set(ax, 'xscale', 'log');

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