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Re: Text data save
Posted:
Oct 14, 2013 9:09 AM


dpb <none@non.net> wrote in message <l0lma3$hrf$1@speranza.aioe.org>... > On 9/9/2013 6:24 PM, Debela wrote: > > ...[Top posting repaired  don't; hard follow conversation makes]... > > > "Steven_Lord" <slord@mathworks.com> wrote in message > > <kv03oc$t8m$1@newscl01ah.mathworks.com>... > >> > >> > >> "Debela " <bisaye@gmail.com> wrote in message > >> news:kv01sd$qkf$1@newscl01ah.mathworks.com... > >> > Hi all, > >> > I have a problem on analysis of big matrix data, it is 1600x3000. > >> What I > wanted to do is to select the maximum value of each raw and > >> save it. For > example, x=data(3,:); max(x); can give me the maximum > >> value of 3rd raw > out of 1600 but I want for all of them I tried a > >> for loop and it is not > really successful. Any help would be > >> appreciated. > >> > Debela > >> > >> Use the DIM input to the MAX function. > >> > >> x = magic(7); > >> maxDownColumns = max(x, [], 1) > >> maxAcrossRows = max(x, [], 2) > ... > > > Thanks a lot. I still have some issues though. I wanted to find the > > maximum and corresponding index (Which I can find now), but I want also > > another value. For example if my maximum value is x, I want to find the > > index of 0.8 *x and 0.002*x. The closest I came across is I multiplied > > the maximum values by 0.8 and 0.002. Is there anyway I can find > > something out of it. I have done in the past using for loop, the data > > size was smaller though. Thanks. > > Same idea, just > > ix=find(x==0.8*xmax); % for example > > NB: the above is subject to floating point roundoff; use > > ix=find(abs(x0.8*xmax)<1E6); % or similar w/ a suitable error > >  > > Thank you for your response. Let me explain what I did and what exactly I wanted. I have a matrix size 1200x750; If I wanted to find the maximum values on all 1200 files I can use the one suggested by Steven. I used that to find the maximum values and I still have questions about the idea mentioned just above by dpd. I want to find for all 1200 files the 0.005* of the maximum and 0.8*of the maximum. file=1200x750; x=file(1,:); % the first file xmax=max(x); b=find(x>=0.8*xmax); b1=b(1); c=find(x>=0.005*xmax); c1=c(1); and I want to save these c(1) and b(1) values. This perfectly works if I work for each file individually but I want to find for all files (1200). Any ideas would be appreciated. Regards



