How to use find function to create a sceond array?

3 vues (au cours des 30 derniers jours)
Patrick
Patrick le 6 Nov 2012
I'm trying to use find function to create a new array(Y) where the values are natural logarithms of an array (X) if these values are greater than 1. If there are any values remaining in (Y), I need to add 8 to each of the corresponding elements in A.
So far I got this but I'm pretty sure I've got something missing as I dont think I get the right result:
bold
X=[1.92 0.05 -2.43 -0.02 0.85];
Y=zeros(size(X));
log=find(log(X)>=1);
Y(1:length(log))=X(log);*
Any advice would be helpful, thank you.
  7 commentaires
Azzi Abdelmalek
Azzi Abdelmalek le 6 Nov 2012
Modifié(e) : Azzi Abdelmalek le 6 Nov 2012
it's not clear, how did you get 0.2833
Patrick
Patrick le 6 Nov 2012
add 8

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Azzi Abdelmalek
Azzi Abdelmalek le 6 Nov 2012
Modifié(e) : Azzi Abdelmalek le 6 Nov 2012
Don't use log as a variable, because it's a logarithme function
note that log of a negative number is complex
log(-6)
  3 commentaires
Patrick
Patrick le 6 Nov 2012
Thanks, I'll try to go with this but still not sure how to add that 8 when value is less than 1.
Azzi Abdelmalek
Azzi Abdelmalek le 6 Nov 2012
then use
X=[1.92 0.05 -2.43 -0.02 0.85];
Y=8*ones(size(X));
lo =find(X>=1);
Y(1:length(lo))=log(X(lo ));

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