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Tomy's profile - activity

2014-08-01 18:52:32 +0100 received badge  Student (source)
2014-07-31 21:30:30 +0100 asked a question convert output

Hello, if a function gives an output like this

2.00000000000000 - 2.77555756156289e-17*I

how could one convert it to be simply

2

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2013-03-28 18:33:49 +0100 received badge  Editor (source)
2013-03-28 18:33:01 +0100 asked a question construct modular forms with nebentypus

Hello , I am sage newbie and looking to create an examples of modular forms with nebentypus .

Let $M_{k}^{-}\left(D,\chi_{-D}\right)$ the subspace of modular forms of weight $k$ on $\Gamma_{0}\left( D \right)$ with nebentypus $\chi_{-D} :=\Big(\frac{-D}{\cdot}\Big)$ whose Fourier expansion is of the forms

$f=\displaystyle\sum_{{n\geq 0 \chi_{-D}(n)\not = 1 }}{a_f (n) q^n}$

i.e. such that $a_f (n)=0 $ if $\chi_{-D}(n) =+ 1 $

I just not sure how to start with this I tried to create space of modular form with character and then look for generators which satisfy these relations for example

D=5

e = DirichletGroup(D), RationalField()).gen()

M=ModularForms(e,5,prec=20);print M

f=M.gen(0);print 'generator=';f

any comment , idea ? best regards