# Norm in UniversalCyclotomicField

Hi,

I'm trying to work with vectors in the `UniversalCyclotomicField`

, But I can't find a way to make the norm work. I'm writing the following code :

```
sage: a = vector([E(8)])
sage: a.norm()
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-2-5b5ddb3f4c99> in <module>()
----> 1 a.norm()
/home/[name]/SageMath/local/lib/python2.7/site-packages/sage/modules/free_module_element.pyx in sage.modules.free_module_element.FreeModuleElement.norm (build/cythonized/sage/modules/free_module_element.c:12840)()
1671 sqrt(5)
1672 """
-> 1673 abs_self = [abs(x) for x in self]
1674 if p == Infinity:
1675 return max(abs_self)
TypeError: bad operand type for abs(): 'UniversalCyclotomicField_with_category.element_class'
```

And having no luck with it. Does any of you know a workaround allowing me to stay in exact calculations ?

Thanks in advance

Maybe using

to make your own norm method for vectors ?