Comment #2 on issue 1857 by ronan.l...@gmail.com: evalf/simplify accuracy
http://code.google.com/p/sympy/issues/detail?id=1857
In [5]: mu0 = 4*pi*1e-7
In [6]: srepr(mu0)
Out[6]: Mul(Real('3.9999999999999998e-7', prec=15), Pi())
mu0 and eps0 are only defined to 15 digits precision (i.e.
machine-precision),
because 1e-7 is a built-in Python 64-bit float. So, the 100 digits of
precision
claimed by evalf are spurious - which your tests clearly demonstrate.
This is not a bug in sympy internals, but the interface could be clearer.
Do you have
any suggestions to improve it?
mu0 = 4*sympy.pi*sympy.S(10)**-7 should behave more like you want.
--
You received this message because you are listed in the owner
or CC fields of this issue, or because you starred this issue.
You may adjust your issue notification preferences at:
http://code.google.com/hosting/settings
--
You received this message because you are subscribed to the Google Groups
"sympy-issues" group.
To post to this group, send email to sympy-iss...@googlegroups.com.
To unsubscribe from this group, send email to
sympy-issues+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/sympy-issues?hl=en.
