Scatterplot legend and fill not working in Octave - octave

Question

I am using Octave.
My problem is this: I want to fill the bubbles of my scatter plot, as well as place a legend. But I get errors when I try to use 'filled', and no legend comes up when I use legend(...).
Part of my code looks like this:
%ALL SAMPLES, PHI(Signal) # THETA(Sample)=0
figure(5)
plot( Angles(:,1)([18:27]), ALL([18:27]), 10, [1 0 1]); %Magenta
hold on
scatter(Angles(:,1)([68:76]), ALL([68:76]), 10, [0 0 0]); %Black
scatter(Angles(:,1)([86:95]), ALL([86:95]), 10, [1 0 0]); %Red
scatter(Angles(:,1)([119:127]), ALL([119:127]), 10, [0 1 0]); %Green
scatter(Angles(:,1)([133:141]), ALL([133:141]), 10, [0 0 1]); %Blue
hold off
xlabel('Signal PMT angle (Sample angle at 0)');
ylabel('Normalized (signal/monitor) intensity');
legend('Control', 'Control', '1+2','Virgin','Cycle #1', 'Location','NorthEast');
title('Plot of All Samples, "-int Intensity"')
I know it should beplot( Angles(:,1)([18:27]), ALL([18:27]), 10, [1 0 1], 'filled');, but I receive errors when I do that. Also, a legend never seems to show up.

Answer 1

Apparently there is a problem with using legend with scatter in Octave. Based on this post:
http://octave.1599824.n4.nabble.com/Legend-in-scatter-plot-td3568032.html
the trick is to use the plot function to make scatter plot. I wrote the following function for plotting a bunch of scatter plots on the same axis.
This function takes in a bunch of cell arrays of the same length. Each element of the cell array corresponds to a separate series. The function returns a cell array of the same length containing the handle associated with each plot. The arguments of the function are explained below:
x_vals: a cell array of arrays of doubles corresponding to x values.
y_vals: a cell array of arrays of doubles corresponding to y values.
sizes: a cell array of doubles representing the size of the markers.
colors: a cell array of double arrays of length 3, representing [R, G, B] color values of the markers.
styles: a cell array of strings representing the shape of the markers.
function [handles] = scatter_series_set(x_vals, y_vals, sizes, colors, styles)
N = length(x_vals);
if ( (~ ( N == length(y_vals))) || (~ ( N == length(sizes))) || ...
(~ ( N == length(colors))) || (~ ( N == length(styles))) )
error('scatter_series_set: all arguments must be cell arrays of the same length');
end
%plot the first series
handles = cell([N, 1]);
handles{1} = plot(x_vals{1}, y_vals{1});
set(handles{1}, 'linestyle', 'none');
set(handles{1}, 'marker', styles{1});
set(handles{1}, 'markersize', sizes{1});
set(handles{1}, 'color', colors{1});
%plot additional series if present
if N > 1
hold on;
for ind = 2:N
handles{ind} = plot(x_vals{ind}, y_vals{ind});
set(handles{ind}, 'linestyle', 'none');
set(handles{ind}, 'marker', styles{ind});
set(handles{ind}, 'markersize', sizes{ind});
set(handles{ind}, 'color', colors{ind});
end
hold off;
end
end
The following example demonstrates how to use this function.
x1 = 0:(2*pi/100):(2*pi);
x2 = 2*x1;
y1 = sin(x1);
y2 = cos(x1);
y3 = sin(x2);
y4 = cos(x2);
names = {'a', 'b', 'c', 'd'};
x_vals = {x1, x1, x1, x1};
y_vals = {y1, y2, y3, y4};
sizes = {10, 10, 10, 10};
colors = {[1, 0, 0], [0, 0, 1], [0, 0, 0], [0.7071, 0, 0.7071]};
styles = {'^', 's', 'x', '+'}
scatter_series_set(x_vals, y_vals, sizes, colors, styles);
legend(names, 'location', 'southeast');
The example code produces the following plot:

Answer 2

The following works for me:
n = 100;
x = randn(n, 1);
y = randn(n, 1);
S = rand(n, 1)*20;
hold on
scatter(x(1:50), y(1:50), S(1:50), "red", "filled")
scatter(x(51:100), y(51:100), S(51:100), "green", "filled")
hold off
print('-depsc', 'bubbleplot.eps');
However, I'm not able to add a legend, and I didn't find any bug report or indication of a missing functionality for this. So, as an alternative, I would suggest adding marker and text to your plot.