# Taking data from loops and the plotting them outside the loop

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Austin Hernandez on 27 Apr 2020
Edited: Mehmed Saad on 27 Apr 2020
I need to plot a graph based upon the answers given (there's a prompt window before this).
In my for loop, I have an if, elseif, and else statement, which gives 3 very different values. Should I try to put all these into 1 cell array? How can I access the data of each array and then plot it?
Or, if I do this step (make a matrix and not an array) and construct a matrix for each of the 3 options. So if it were like:
h = 0:1:10
y = zeros(size(h));
v = zeros(size(h));
o = zeros(size(h));
prompts = {'enter 1'};
dlg = 'title';
hold on
for i=1:5
A = inputdlg(prompts, dlg);
Aa = str2double(A);
x = Aa(1);
if x == 1
y(i,:) = 1000*h;
m = m + 1;
plot(h,y(i,:));
elseif x == 0
v(i,:) = h+1;
u = u + 1;
plot(h,v(i,:));
else
o(i,:) = -h*5;
c = c + 1;
plot(h,o(i,:));
end
end
end
This will give 3 different matrices of the 3 different types of answers. When I used this option, this method will generate a new row in the matrix of each output. So if I'm on loop 5, and the if statement is triggered, and I triggered the same statement in the very first loop, then I'll get a matrix like:
v =
1 2 3 4 5 6 7 8 9 10 11
0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0
1 2 3 4 5 6 7 8 9 10 11
How can I take the data from the rows that have nonzeros and then plot them with different boundaries on the x-axis?

Mehmed Saad on 27 Apr 2020
Initialize these variables
m=1;u=1;c=1;
replace i with m,u and c in their cases
if x == 1
y(m,:) = 1000*h;
plot(h,y(m,:));
m = m + 1;
elseif x == 0
v(u,:) = h+1;
plot(h,v(u,:));
u = u + 1;
else
o(c,:) = -h*5;
plot(h,o(c,:));
c = c + 1;
end
##### 2 CommentsShowHide 1 older comment
Mehmed Saad on 27 Apr 2020
There's another way but it is computationaly costly and not recommended
h = 0:1:10
y=[];v=y;o=[];
prompts = {'enter 1'};
dlg = 'title';
hold on
for i=1:5
A = inputdlg(prompts, dlg);
Aa = str2double(A);
x = Aa(1);
if x == 1
y = [y;1000*h];
plot(h,y(end,:));
elseif x == 0
v = [v;h+1];
plot(h,v(end,:));
else
o = [o;-h*5];
plot(h,o(end,:));
end
end
the size of y,v and o are changing in each loop iteration and is very inefficient. R2020a

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