How can I find the average of largest set of non-zero values in an array

Question

How can I find the the starting point of A array and calculate average starting from starting points to 1 second

A=[0 0 0 0 0 -0.01 -0.2 0.3 0.4 0.5 0 0 0 0 0 0 0.01 0.02 0.03 0.04 0.1 0.2 0.3 0.4 0.7 0.8 1 1.2 1.3 1.4 1.5]

Time=[0 0.1 .2 .3 .4 .5 .6 .7 .8 .9 1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.8 3 3.1]

By removing the noise the starting point should be A(17) which is equal to 0.01

Then calculate average of A starting from starting point after 1 seconds

noise values are from A(6) to A(10). I want data starting from the first nonzero where the graph becomes constant and will not become zero again — user183060
So largest set of non zero values occurring continuously is considered as data right? — Rijul Sudhir

Rijul Sudhir Rijul Sudhir · Accepted Answer · 2018-07-21T18:35:54

Code is self explanatory

A=[0 0 0 0 0 -0.01 -0.2 0.3 0.4 0.5 0 0 0 0 0 0 0.01 0.02 0.03 0.04 0.1 0.2 0.3 0.4 0.7 0.8 1 1.2 1.3 1.4 1.5] ;
Time=[0 0.1 .2 .3 .4 .5 .6 .7 .8 .9 1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.8 3 3.1];

%make negative values zero
A(A<0)=0; 

%get non negative values position and add padding
mask=[0,A>0,0]; 

%get starting points
startingPoints =strfind(mask,[0 1]); 

%get length of continuous values from starting points
temp =diff(find(~mask))-1;
length = temp(temp>0); 

%get the index of largest length
[~,index]=max(length);

%get starting point
dataStartingIndex = startingPoints(index)

%starting point value
A(dataStartingIndex)

%get ending point after 1 seconds
dataEndingIndex=find((Time(dataStartingIndex)+1)==Time);

%find average
avg=mean(A(dataStartingIndex:dataEndingIndex))

How can I find the average of largest set of non-zero values in an array

2 Answers