How to pre-allocate a struct in Matlab
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Hamed Bolandi
on 19 Jul 2019
Commented: Hamed Bolandi
on 19 Jul 2019
I want to pre-allocate stuct e1 and struct e3 in the following loop. I would be thankfull if someone can help.
clc;
clear;
close all;
x=[-30;-25;-20;20;25;30;30;25;20;-20;-25;-30];
y=[-25;-25;-25;-25;-25;-25;25;25;25;25;25;25];
i=x(1:end);
j=y(1:end);
M=[i,j];
s.x=[];
s.y=[];
c=repmat(s,12,1);
c(1).x=M(1,1);
c(1).y=M(1,2);
c(2).x=M(2,1);
c(2).y=M(2,2);
c(3).x=M(3,1);
c(3).y=M(3,2);
c(4).x=M(4,1);
c(4).y=M(4,2);
c(5).x=M(5,1);
c(5).y=M(5,2);
c(6).x=M(6,1);
c(6).y=M(6,2);
c(7).x=M(7,1);
c(7).y=M(7,2);
c(8).x=M(8,1);
c(8).y=M(8,2);
c(9).x=M(9,1);
c(9).y=M(9,2);
c(10).x=M(10,1);
c(10).y=M(10,2);
c(11).x=M(11,1);
c(11).y=M(11,2);
c(12).x=M(12,1);
c(12).y=M(12,2);
for i=1:27
j=c(2);
k=c(4);
l=c(7);
o=c(10);
e3(i,:)=[j;k;l];
for i=1:3:25
o=c(10);
e1(i,:)=o;
end
for i=2:3:26
o=c(11);
e1(i,:)=o;
end
for i=3:3:27
o=c(12);
e1(i,:)=o;
end
for i=4:6
k=c(5);
e3(i,:)=[j;k;l];
end
for i=7:9
k=c(6);
e3(i,:)=[j;k;l];
end
for i=10:18
l=c(8);
e3(i,:)=[j;k;l];
end
for i=13:15
k=c(5);
e3(i,:)=[j;k;l];
end
for i=16:18 %#ok<*FXSET>
k=c(6);
d3(i,:)=[j;k;l];
end
for i=19:27
l=c(9);
e3(i,:)=[j;k;l];
for i=22:24
k=c(5);
e3(i,:)=[j;k;l];
end
for i=25:27
k=c(6);
e3(i,:)=[j;k;l];
end
end
e=[e3,e1];
end
4 Comments
Rik
on 19 Jul 2019
Try to write some comments in your code what it is doing. You are overwriting entries several times without any clear reason. The answer below (zeros(27,3)) will work, but is likely not your problem.
Accepted Answer
Sulaymon Eshkabilov
on 19 Jul 2019
Edited: madhan ravi
on 19 Jul 2019
Did you mean memory pre-allocation? if so, then
e1=zeros(27,1);
e3=ones(27,3);
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