min and max were initiated as aValuesX[0] which could be NaN
test i before evaluating aValuesX[i]

Change-Id: I0246913dcf427e59fd354321eeffa7c08c41c08d
Reviewed-on: https://gerrit.libreoffice.org/17772Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>