How Can i write a function that takes a structure array and returns this array with bubble sorting

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Dart Min 2019-11-26

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评论： Walter Roberson 2019-11-27

I want to write a function that takes a structure array holding information about students(name,age,gpa etc.) and returns this array by ordering the students with respect to their age by bubble sort.

function  a=structarray (age,a)
for i=1:length(a)-1
  if a(i).(age)>a(i+1).(age)
    T=a(i);
    a(i)=a(i+1);
    a(i+1)=T;

i write this. but of course it is not working.pls guys help me.

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Walter Roberson 2019-11-26

When you call the function, passing in that a as the second parameter, what would you pass in as the first parameter?

What difficulties are you observing with your code?

Dart Min 2019-11-26

I can't call the function. I don't know what should i put in argument side. So i think the header section is wrong. when i write "function a=structarray(a)" is also not working.

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Walter Roberson 2019-11-26

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在 MATLAB Online 中打开

function  a=structarray(a)
for i=1:length(a)-1
  if a(i).age > a(i+1).age
    T=a(i);
    a(i)=a(i+1);
    a(i+1)=T;
  end
end

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Dart Min 2019-11-27

thanks a lot. but now only a(3) and a(4) changed. Then function stopped.

Walter Roberson 2019-11-27

That is because your bubble sort algorithm needs more work.

You only make a single pass through the data. But suppose the least age was in the last entry. Your code would exchange that with the second last entry, but would not then proceed to "bubble" that lowest age from the second last entry all the way back to the first entry.

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Stijn Haenen 2019-11-26

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在 MATLAB Online 中打开

struc.mat

Maybe this will work:

ages=[structurearray.age];
[a,b]=sort(ages);
newstructurearray=structurearray(b);

The used structure is attached.

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Stijn Haenen 2019-11-26

在 MATLAB Online 中打开

Ah i missed that,

maybe this:

a(1).name='Matt';
a(1).age=22;
a(1).gpa=77;
a(2).name='Chris';
a(2).age=23;
a(2).gpa=45;
a(3).name='Park';
a(3).age=26;
a(3).gpa=81;
a(4).name='Stewie';
a(4).age=19;
a(4).gpa=44;
ages=[a.age];
[b]=unique(ages);
new_a=[];
for i=1:numel(b)
    num=(ages==b(i));
    new_a=[new_a;a(num)];
end