Scattered plot for different groups of data, subplot?

Let say I have a table which contains three columns, Country (4 countries), Variable x and Response y. I would like to know how to create a plot for each country in a single figure?

gscatter (Table.x, Table.y, Table.Country) %This only allows me to plot all four in one graph.

Answer 1

[Walter Roberson]

[u_country, ~, idx] = unique(Table.Country);
for K = 1 : 4
  subplot(2,2,K)
  mask = idx == K;
  gscatter(Table.x(mask), Table.y(mask), Table.Country(mask));
  title( u_country );         %you might need to adjust this depending on the class() of your country data
end

[wesleynotwise]

It doesn't really work, but I think we are getting there. I have a figure (let say figure 1) before this figure (figure 2) with subplots. When I apply your codes, my figure 1 is affected, and it becomes a blank subplot in the position (2,2,1). And, the second to forth subplots in my figure 2 are okay, but the first subplot is missing (I assume it's somehow being read as figure 1?). Any clues?

% This is Figure 1
  figure (01)
  f1 = gscatter(Table.y, Table.predictedy, Tablecountry)
  hold on
  m = 0:10:100; n = m;
  LineofEquality = plot (m,n, 'k', 'Linewidth', 1.75);
  hold off
  legend ([f1])

% This is Figure 2
[u_country, ~, idx] = unique(Table.Country);
for K = 1 : 4
  subplot(2,2,K)
  mask = idx == K;
 f2 = gscatter(Table.x(mask), Table.y(mask), Table.Country(mask));
hold on
m = 20:10:120; n = 0*m;
lineAtX = plot (m,n, 'k', 'Linewidth', 1.75)
hold off
  title(u_country); % *Sorry how to adjust this?*
legend ([f2]) %the label in the legend is incorrect, as it displays the true label as well as the labels of unplotted data?
end

[Walter Roberson]

% This is Figure 2
figure(2)
[u_country, ~, idx] = unique(Table.Country);
for K = 1 : 4
  subplot(2,2,K)
  mask = idx == K;
  gscatter(Table.x(mask), Table.y(mask), Table.Country(mask));
  hold on
  m = 20:10:120; n = 0*m;
  lineAtX = plot (m,n, 'k', 'Linewidth', 1.75)
  hold off
  title( num2str(u_country(K)) );
end

gscatter() automatically creates the legend.

I had to assume here that your Table.Country information is numeric. If it is categorical, then use

      title( char(u_country(K)) );

[wesleynotwise]

Thank you! Beautiful plots have been created. I made a minor correction "f2 = gscatter" to my code.

The legend contains the name of lineAtX (this is just a horizontal line I created for the plot to show the neutral axis where y = 0), and I want to exclude it. Can you please show me how this can be done?

Also, is it possible to change the order they appear in the plot? At the moment, the default setting is in alphabetical order.

[Walter Roberson]

See https://www.mathworks.com/matlabcentral/answers/406-how-do-i-skip-items-in-a-legend#answer_563 for turning off the legend of the extra lines.

If you want to change the order that the countries appear, then you can use

display_order = [2 4 3 1];   %for example

and

% This is Figure 2
figure(2)
[u_country, ~, idx] = unique(Table.Country);
for K = 1 : 4
  subplot(2,2,K)
  this_country = display_style(K);
  mask = idx == this_country;
  gscatter(Table.x(mask), Table.y(mask), Table.Country(mask));
  hold on
  m = 20:10:120; n = 0*m;
  lineAtX = plot (m,n, 'k', 'Linewidth', 1.75)
  hold off
  title( char(u_country(this_country)) );
end