# How to loop a function though multiple datasets

조회 수: 6 (최근 30일)
Sam Mahdi 2019년 3월 11일
편집: Sam Mahdi 2019년 3월 13일
Hello everyone,
I have a bit of a basic question, and I've tried reading other answers on this, but they each seem to have their own specific problem (nor have I been able to successfully implement their solutions to my own issues).
In a nutshell, I have successfully been able to use lsqccurvefit for one of my datasets. I am now trying to create a loop, so I can run the same function on multiple datasets. My code is this:
Data1=[0.596421471 0.06
0.5859375 0.119284294
0.566037736 0.29296875
0.530035336 0.622641509
0.418994413 1.219081272
0.388619855 3.058659218
];
Data2=[5.00E+04 3.82E+04 3.45E+04 3.42E+04 3.74E+04 3.21E+04 2.81E+04 2.88E+04
5.00E+04 3.82E+04 3.45E+04 3.42E+04 3.74E+04 3.21E+04 2.81E+04 2.88E+04
3.08E+04 3.07E+04 2.19E+04 2.23E+04 2.53E+04 2.05E+04 1.98E+04 1.89E+04
2.05E+04 1.87E+04 1.30E+04 1.10E+04 1.62E+04 1.31E+04 1.05E+04 1.05E+04
8963 1.11E+04 6243 3504 6454 4346 4448 4357
0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00
];
Pt=Data1(:,1);
Lt=Data1(:,2);
Int=Data2(:,1);
plot(Lt,Int, 'ro');
xdata=[Pt,Lt]
F=@(x,xdata)((xdata(:,1)+xdata(:,2)+x(2))-((xdata(:,1)+xdata(:,2)+x(2)).^2-4.*xdata(:,1).*xdata(:,2).^1/2).*x(1)/2.*xdata(:,1))
x0=[1 1]
options=optimoptions('lsqcurvefit','MaxFunEvals',5e2)
lb=-Inf
up=+Inf
[x,resnorm,~,exitflag,output]=lsqcurvefit(F,x0,xdata,Int,lb,up,options)
hold on
plot (Lt, F(x,xdata))
hold off
Data 1 is constant and does not change, it is what my function is using. Data2 is my data. I am also plotting my data and the output of the function so I can see how well they match (which has so far been extremely poor matching). What I want to do now is have my [Int] cycle through each column independently, so for the first round it runs the lsqc through column ;1, 2nd round through column ;2, etc. At the same time, I would also like to individuallly (or combined) plot each individual column with the output of the function (for each run it goes through). I know I need to use the "for" function, but I don't quite know how to cycle through each column individually using the Int that I've already defined.
Finally, I had gotten this to work using one column set, but now that I've inputed multiple column sets, I seem to have broken my script. I now get the error
Index in position 1 is invalid. Array indices must be positive integers or logical
values.
Error in Testscript4loop (line 18)
plot(Lt,Int, 'ro');
Which is strange, since before I added all the extra data (Data2 used to be only 1 column), it worked fine.
##### 댓글 수: 10이전 댓글 8개 표시이전 댓글 8개 숨기기
So you will need to store whatever data is relevant in the loop in an array instead of plotting it. As it stands you will end up with a mean value per column of your data, each of which gets thrown away apart from the one for the final column.
Sam Mahdi 2019년 3월 13일
편집: Sam Mahdi 2019년 3월 13일
I see, yes you're right. All M is doing is taking the average of the 2 x2s that I'm solving (x(1) and x(2). It is not actually averaging my loop. I initially thought the difference betwee M and my output was because it was averaging, but it's only different because I have 2 variables, and it's only averaging the values of the 2 variables from each individual run.

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