Counting zeros

Hi,

I would like to know how to calculate the number of zeros in an array and stop when the array value is one.

Example: a = [0 0 0 0 1 1 1 0 0 0]

here, there are 4 zeros before it meet array value of one.

then, let say I convert binary to RGB, 0=green and 1=red. The same thing goes here...how I want to calculate green pixel before it meet red pixel.

Anybody can give any idea. Thank you in advanced.

[marlina]

Let say if 0 remain black, only 1 turn to green. How to calculate black pixel before it meet the first pixel of green?

Answer 1

[dhyun]

one method you could use is to find the first position where a == 1 and then subtract 1 from it:

    num_zeros = find(a == 1, 1) - 1;

[marlina]

Thanks,

for binary its working.

How about in RGB?

[Paulo Silva]

find(diff(a)==1) %green transition to red

find(diff(a)==-1) %red transition to green

[Paulo Silva]

find(diff(a)) %gives two index values, green to red and red to green

[marlina]

Thanks,

I tried it but some error occurred.

Let say if 0 remain black, only 1 turn to green. How to calculate black pixel before it meet the first pixel of green?