find if there are more then 10 consecutive NaN values

Hello

I have a 170 x 1 matrix. Whicht contains 1 and 0 values. 1 is for NaN. I have 170 of this matrices. Is there a way how i can find only the matrices which contain more the 10 consecutive NaN values?

For example I have the following:

A = [ 0 0 1 1 1 1 1 1 1 1 1 1 1 0]
B = [ 1 1 1 1 0 0 1 1 0 1 1 1 1 1]

Now I need a code that gives the solution A, so I now in A are more the 10 consecutive NaN values.

Thanks for your help. Oliver

Answer 1

[Azzi Abdelmalek]

A = [ 0 0 1 1 1 1 1 1 1 1 1 1 1 0]
ii=strfind([0 A 0],[0 1])
jj=strfind([0 A 0],[1 0])
idx=max(jj-ii)

[Oliver Kumar]

Thanks. But I only get the max value with this. But I need all consecutive NaNs values greater than 10. if A = [ 0 0 1 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 1 0] I need 11 and 12 as an answer. is that possible? thank you in advance.

[Azzi Abdelmalek]

A=[ 0 0 1 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 1 0]  
ii=strfind([0 A 0],[0 1])
jj=strfind([0 A 0],[1 0])
idx=jj-ii;
out=idx(idx>=11)

[Oliver Kumar]

Thanks mate

[Image Analyst]

Why 12????

Answer 2

[Image Analyst]

Another 2 line solution:

% Create sample data:
A = [ 0 0 1 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0]
% Measure the lengths of each "run" of ones:
measurements = regionprops(logical(A), 'Area');
theLengths = [measurements.Area]

Answer 3

[Andrei Bobrov]

i1 = find(diff([0 A 0]) == 1);
out = i1(find(diff([0 A 0]) == -1) - i1 > 10);

Answer 4

[Prashant Dwivedi]

Hello, My problem is similer .

I wantedt to consicutive non NaN values . I tried

regionprops for ~isnan.

It does not work .

Any help will appreciated .

Thank you.

[Image Analyst]

Works for me

% Create sample data:
A = [ 0 0 1 1 nan nan nan 1 1 1 1 1 1 nan nan  1 0 0 1 1 1 nan 1 1 nan  1 1 1 0]
% Measure the lengths of each "run" of ones:
measurements = regionprops(logical(~isnan(A)), 'Area');
theLengths = [measurements.Area]

shows

theLengths =
     4     6     6     2     4     

Show how you did incorrectly did it.

[Prashant Dwivedi]

I tried like this :-

clear all
A = [ 2 5 6 2 nan nan nan 3 4 3 5 5 3 nan nan  2 2 3 4 5 5 nan 2 4 nan  4 5 5 6]
% Create sample data:

% Measure the lengths of each "run" of ones:

Mnan = regionprops(logical(A), 'Area');

theLengths = [Mnan.Area];

% Measure the lengths of each "run" of ones:

Mval = regionprops(logical(~isnan(A)), 'Area');

theLengths = [Mval.Area];
knan = length(Mnan)
kval = length(Mval)

But it gives error

Error using logical
NaN's cannot be converted to logicals.

Error in test (line 7)
Mnan = regionprops(logical(A), 'Area');

[Image Analyst]

Of course. And why didn't you do it like I suggested?