extracting values above 0 in an array and putting them in a new array

how can i get a 1x5 array by taking values of non-zero? (e.g. taking the first column and taking the first minimum value greater than zero)?

[Walter Roberson]

Question: for column 4, should the output be 1.6807 as the "first" mininum value that is greater than 0? Or should it be 1.6054 because that is the minimum non-zero value in the row? Or should it be 3.8141 because that is the first non-zero value after the 0 ?

Answer 1

[dipak nigam]

Hey, you can use the below piece of code for your desired functionality.

a(a<=0)=inf;
minArray = min(a);

If you want to keep the original array unchanged first assign it to a temporary variable and use it to extract the result.

[Hatim Altarteer]

this returns a 1x5 array of ZEROs, i want NON-ZEROS minimum value.

[Walter Roberson]

You are incorrect, Hatim

data = [
    0 0.0754 0.2159 1.6807 2.6856
    0.0754 0 0.2911 1.6054 2.7275
    0.2159 0.2911 0 1.8965 2.5913
    1.6807 1.6054 1.8964 0 3.8141
    2.6856 2.7275 2.5913 3.8141 0
    ];

a = data;
a(a<=0) = inf;
minArray = min(a);
disp(minArray)

0.0754 0.0754 0.2159 1.6054 2.5913

No zeros returned at all.

dipak's solution is correct.

Answer 2

[madhan ravi]

 matrix(matrix <= 0) = inf;
 Wanted = min(matrix)

[Hatim Altarteer]

this returns a 1x5 array of ZEROs, i want NON-ZEROS minimum value.

[madhan ravi]

Huh?

 >> matrix = [.1, -1;...
           0, .01;...
          .03, 0]
 matrix(matrix <= 0) = inf
 Wanted = min(matrix)

 matrix =

    0.1000   -1.0000
         0    0.0100
    0.0300         0

 matrix =

    0.1000       Inf
       Inf    0.0100
    0.0300       Inf

 Wanted =

    0.0300    0.0100

[KALYAN ACHARJYA]

"extracting values above 0 in an array and putting them in a new array"

then I am not getting the question till yet.

[madhan ravi]

Well you need to read the content as well , not the question alone.

[Hatim Altarteer]

thanks, it was just a syntax eroor. my bad (Y)

[madhan ravi]

Hatim you need to accept dipak’s answer because he was first before me. I was typing the answer in my phone so didn’t realise there was an answer already.