numpy is the only known issue for a possible sagemath package for f18 know. I made a build and added to my updated repository at http://pcpa.fedorapeople.org/sagemath/f18/x86_64/ But it would be preferable to have it official now.
numpy-1.7.0-0.5.rc1.fc18 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/numpy-1.7.0-0.5.rc1.fc18
Package numpy-1.7.0-0.5.rc1.fc18: * should fix your issue, * was pushed to the Fedora 18 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing numpy-1.7.0-0.5.rc1.fc18' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2013-1109/numpy-1.7.0-0.5.rc1.fc18 then log in and leave karma (feedback).
numpy-1.7.0-0.5.rc1.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report.