Problem with the find function
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Hi all,
I have a problem with my code and can't find what's wrong with it. Can someone help me?:(
I'm trying to sum the energy between two indexes,which is the interval of 10s.I use the find function but I get a message error:
??? Improper assignment with rectangular empty matrix.
Error in ==> testtaux2 at 29
klow(i)=find (temps >=t2(i),1,'first');
and here is my code:
clear all
close all
data2=load('SML64_long_AE_correct.txt');
data=load('trx9_SML64d_mod3.txt');
%data3=load('count.txt');
%t=data(:,1);
%def=data(:,12);
Q=data(:,11);
Ener=data2(:,14);
temps=data2(:,4);
def=data2(:,7);
defm=data(:,16);
amplitude=data2(:,12);
count=data2(:,9);
cumul_ener=data2(:,17);
dt=10;
k=0;
n=0;
for i=1:length(temps)-dt
t2(i)=temps(1)+n*dt;
t1(i)=t2(i)+dt;
n=n+1;
klow(i)=find (temps >=t2(i),1,'first');
kup(i)=find(temps >t1(i)+2*dt,1,'first');
dE(i)=sum(Ener((klow(i)):kup(i)));
t(i)=temps(klow(i))+temps(kup(i))/2;
k=k+1;
taux(k)=dE(i)/dt;
tt(k)=t(i);
end
%file = fopen('tauxfixe.txt','w');
% fprintf(file,' %f %f\n',taux(k),tt(k));
% fclose(file);
figure
plot(tt,taux)
hold on
Does anyone know what is wrong with my code?
Thank you very much for your help and sorry for my bad English !
回答（3 个）
per isakson
2014-4-6
0 个投票
Here are some links on debugging in Matlab
Roger Stafford
2014-4-6
I would guess offhand that when the 'find' function happens to come up empty at
klow(i)=find (temps >=t2(i),1,'first');
then matlab complains about trying to insert an empty array into a single space. If so, you will have to make some special provision for the empty case.
maxime bernard
2014-4-7
Thank you for your answer. I have tried to change it by replacing the "n" with "kk" index but I still get this messqge error.Do you know whatI can I do it? I have tried so many things and I always this problem.
dt=10;
k=0;
kk=1;
for i=1:length(temps)-dt
t1(i)=temps(kk);
t2(i)=t1(i)+dt;
klow(i)=find (temps >=t1(i),1,'first');
kup(i)=find(temps >t1(i) +dt,1,'first');
dE(i)=sum(Ener((klow(i)):kup(i)));
t(i)=temps(klow(i))+temps(kup(i))/2;
kk=kup(i);
k=k+1;
taux(k)=dE(i)/dt;
tt(k)=t(i);
end
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2014-4-7
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