Finding Patterns in Array

Hi, I am currently using the 'findpattern' function (which can be found here ) to find patterns in temperature data.

e.g. find the index when temperature was at 10 degrees for 2 hours. in this case my pattern would be [10 10 10 10 ...] and findpattern.m would find the index in the start value. My temperature data was taken every 5 min which dictates the length of the pattern.

I would like to have a range of temperatures instead of 1 value i.e. find the locations when temperature was anywhere between 9 and 11 degrees for 2 hours.

[Stephen23]

@Connor O'Higgins: what is your question?

[Connor O'Higgins]

Sorry, that wasn't well explained

I need to find the locations in my temperature data where the temperature has been steady for several hours.

However, this temperature should be in a range i.e. 9 to 11 degrees.

Answer 1

[Guillaume]

%T: temperature vector
%desiredduration: number of samples where temperature must be between 9 and 11

inrange = T>=9 & T<= 11;
transitions = diff([false; inrange; false]); %find where the temperature change between in range/not in range occur
inrangestarts = find(transitions == 1);
inrangeends = find(transitions == -1);
inrangeduration = inrangeends - inrangestarts;  %may be off by 1. Check
locs = inrangestarts(inrangeduration > desiredduration)

[Connor O'Higgins]

Thanks Guillaume, That does the job. The 'inrangeduration' did need a +1 like you said.

Answer 2

[Image Analyst]

Attach your data or image. If you have a known pattern you're looking for, rather than trying to guess at patterns and finding some pattern that might be repeated somewhere, then you can use normxcorr2(). A demo is attached.