Median of Medians in Java

Question

I am trying to implement Median of Medians in Java for a method like this:

Select(Comparable[] list, int pos, int colSize, int colMed)

Answer 1

@android developer :

for (i = 1 to n/5) do
    x[i] = select(S[i],3)

is really

for (i = 1 to ceiling(n/5) do
    x[i] = select(S[i],3)

with a ceiling function appropriate for your data(eg in java 2 doubles) This affects the median as well wrt simply taking n/10, but we are finding closest to the mean that occurs in the array, not the true mean. Another note is that S[i] may have fewer than 3 elements, so we want to find the median with respect to length; passing it into select with k=3 won't always work.( eg n =11, we have 3 subgroups 2 w 5, 1 w 1 element)