Ranjan Kumar February 2016
### np.poly1d() exclude printing variable(x), if coefficient is 0 or -0, but it includes if it is -0.0

`numpy.poly1d()`

exclude printing variable(x) if coefficient is 0 or -0, but it includes if it is -0.0

Example:

print np.poly1d([1,-0.0,3]) 2 1 z + 3 print np.poly1d([1, 0, 3]) 2 1 z + 3 print np.poly1d([1, -0.0, 3], variable='z') 2 1 z - 0 z + 3

Why it is so?

Well it is because python saves (or at least prints) these zeros differently:

```
print(0)
0
print(-0)
0
print(0.0)
0.0
print(-0.0)
-0.0
```

and numpy only ignores coefficients that are not `0`

but it ignores the decimal places if they are only zeros. (see source).

This means that everything except `-0.0`

is evaluated as `0`

and not shown.

Asked in February 2016

Viewed 3,660 times

Voted 9

Answered 1 times

Viewed 3,660 times

Voted 9

Answered 1 times