This has nothing to do with numpy, the issue is the string "%" operator cannot convert list to a float (Line 3 in your example gives a list). In '"%f" % x' the x has to be a number or tuple.
Does not work:
print "%f" % [1.0]
Works:
print "%f" % 1
print "%f" % (1, )
print "%f" % tuple([1])
print "%f" % a[0]
Hope this helps,
Pavol
--
http://mail.python.org/mailman/listinfo/python-list
