How to create multiple legends - depending on number of inputs

So I basically have this function y which varies on a chosen number nabla. I have written a function that takes in a chosen number of nablas and plots the corresponding y value to a given x interval, here it is:

if true
function nablaplot(n)
%writing in the number n of inputs and creating a matrix
%calculating my matrix y which I will plot
for i=1:n
nabla(i)=input(sprintf('Enter nabla value number %i: ',i));
y(i,:) = 2.*x - 2.*x.^3 + x.^4 + (nabla(i)/6).*x.*(1-x).^3 ;
end 
x=0:0.01:1; %step length
figure
y1= 0*x;            %x-axis
plot(x,y1,':black') %x-axis
hold on
plot(x,y)           %here I plot the number n of graphs
axis([0 1 -0.2 2])  %boundaries
hold off
end
end

This function prints the given number n of graphs into a single plot - which is what I want! But is there any way to plot n legends which states what nabla value each graph has?

[Michael Madelaire]

But this function opens a new figure for every iteration. Do you want a legend in every figure?

[Jakob]

I think you have to open the figure first and hold it. Then use 'legend('nabla1', 'nabla2',...)' to draw the legend, the nablas have to be in the right order, tho. So first open figure and hold it before you begin the loop. everything should be plotted in that figure then.

I dont know if you can use 'legend(['nabla' i])' at each iteration, if it doesnt work, just use legend after you finished the loop, with an array containing all the names for the nablas.

[Erica Miller]

Is there an efficient way to add different colors to each nabla in this same 'for' loop?

Answer 1

[Jakob]

for example:

    figure;
    hold on;

    x=1:10

    for i=1:3
        plot(i*sin(x));
        nabla(i)=i;
    end
    leg=string(nabla); %converts integer-array to string array
    legend(leg);

So your values for nabla have to be in a string array and in the right order, which is the input to the legend(...) function.

[Jonas Ravndal Kildal]

Hi, I used this and worked out a solution, thanks! (Changed nabla to lambda)

figure

hold on
plot(x,y)           %here I plot the number n of graphs
axis([0 1 -0.2 2])  %boundaries
grid on

leg = string(lamdba);

for j = 1:n
   leg(j) = '\Lambda = ' + leg(j);
end

legend(leg)