BUG: no implicit casting
BUG: no implicit casting

On some versions of numpy, implicit cast raises an error:

TypeError: Cannot cast array data from dtype('uint64') to dtype('int64')
according to the rule 'safe'

alexis-roche/nipy,arokem/nipy,arokem/nipy,arokem/nipy,alexis-roche/niseg,alexis-roche/nipy,alexis-roche/nireg,alexis-roche/nipy,alexis-roche/register,alexis-roche/nipy,arokem/nipy,alexis-roche/nireg,alexis-roche/register,alexis-roche/niseg,alexis-roche/register,nipy/nireg,nipy/nireg