Why centroid value is in float instead of integer?

I have eight white blog images in black background. When i was calculate centroid of each i get float type answers about four decimal(320.1425).

I have a doubt in this. All the images in taken as a matrix form right. Then the centroid will be only as integer. But actually it is not, why?

Answer 1

[Image Analyst]

Why do you think the centroid should be an integer? Is the average of two integers, 4 and 5, an integer? No - it's 4.5. So why should centroids be integer? You can round to the nearest integer if you want with the int32() function:

centroid_x_int = int32(centroid_x);