Using Variable in Legend in for loop

I want to use variable in legend in a scatter plot. I found similar questions about variable in legend. However, they are not in a for loop. I need it in a for loop. How can I do this? My code is :

close all;clear all; clc;
x=-20:5:20;
y=-20:5:20;
z=40:5:80;
[X,Y,Z]=meshgrid(x,y,z)
h=0;
for i=1:1:length(x)
    for j=1:1:length(y)
        for k=1:1:length(z)
            h=h+1
          M(h,:)=[X(i,j,k), Y(i,j,k), Z(i,j,k)];
          N(h)=bul_poz_real_cozum_sayisi([M(h,1); M(h,2); M(h,3) ],[0;0;0]);
          end
    end
end

NN = unique(N); NN_length=length(NN);
BB = unique(B); BB_length=length(BB);

S=[10 10 20 20 30 ];
figure; hold on;

for i = 1:NN_length
    NNN = (N == NN(i));    % Without FIND: faster logical indexing
    scatter3(M(NNN, 1), M(NNN, 2), M(NNN, 3), S(i),'filled');hold on;
    str = {strcat( num2str(NN(i)), 'Solutions')};
    legend(str{:})
end
xlim([x(1),x(end)]);ylim([y(1),y(end)]);zlim([z(1),z(end)]);
axis equal; grid on;rotate3d;view(3);

It only writes the last legend, and deletes the preious legend. NN=[4 6 8 10 12]. So the legend should be like this:

• 4 Solutions
• 6 Solutions
• 8 Solutions
• 10 Solutions
• 12 Solutions

Answer 1

[Srivardhan Gadila]

Refer to Add Legend to Graph for more information.

You can make use of the 'DisplayName' name value pair argument as follows:

x = 1:4;
figure 
hold on
for i=1:4
    z = linspace(0,4*pi,250)/i;
    x = 2*cos(z) + rand(1,250);
    y = 2*sin(z) + rand(1,250);
    scatter3(x,y,z,'filled','DisplayName',num2str(i))
end
legend