sqrt and log of rational series

[Sergey-A-Dovgal]

It seems that if one of the coefficients of a rational power series is a non-integer then the condition that the constant term is one, fails.

Example.

import flint

QQ = flint.fmpq
log = flint.fmpq_series.log

# this one works ok
print(log(flint.fmpq_series([1,1])))

# here is I get ValueError: log() of power series: constant term must be one
print(log(flint.fmpq_series([1,1,QQ(3,8)])))

The same goes with sqrt.

My best guess is that it is because fmpq series is represented as a fraction, and it thinks that the leading term is equal to 8.

My flint version is 2.7.1, and python-flint is 0.3.0

Cheers

[oscarbenjamin]

This one seems to be working fine now with python-flint 0.6.0:

In [1]: import flint
   ...: 
   ...: QQ = flint.fmpq
   ...: log = flint.fmpq_series.log
   ...: 
   ...: # this one works ok
   ...: print(log(flint.fmpq_series([1,1])))
   ...: 
   ...: # here is I get ValueError: log() of power series: constant term must be one
   ...: print(log(flint.fmpq_series([1,1,QQ(3,8)])))
x + (-1/2)*x^2 + 1/3*x^3 + (-1/4)*x^4 + 1/5*x^5 + (-1/6)*x^6 + 1/7*x^7 + (-1/8)*x^8 + 1/9*x^9 + O(x^10)
x + (-1/8)*x^2 + (-1/24)*x^3 + 7/128*x^4 + (-11/320)*x^5 + 23/1536*x^6 + (-13/3584)*x^7 + (-17/16384)*x^8 + 73/36864*x^9 + O(x^10)

Looks like it was fixed in c715d51 from gh-39 so python-flint 0.4.0.