DirSizePretty

Determine the size of a folder/directory in bytes without needing to add function to path as well as human readable output

directory_path = 'C:\';
byteCount = DirSize(directory_path);

returns the number of bytes in the directory_path (e.g. 31,400,000)
or

byteCountString = DirSizePretty(directory_path);
returns the number of bytes in a human readable string (e.g. '31.4 MB')

Also, this was inspired by Richard Moore's DirSize, but I found that DirSize.m needed to be added to the Matlab path to function, something that I don't use in my applications. This version works without adding to the Matlab path, although that should still work