Largest memory block available (All platforms)

Find the largest contiguous memory block available for array allocation on all platforms.

>> largestmemblock
Maximum contiguous block is approximately:
(Accurate to 95% of real memory value)
833019 KB
813 MB

% More accurate value
>> largestmemblock([],0.9999)

Maximum contiguous block is approximately:
(Accurate to 95% of real memory value)
835717 KB
816 MB