Hi Josh!

On Mon, Apr 12, 2010 at 11:37 AM, Josh <[email protected]> wrote:
> I just started using sympy a couple of days ago and am playing with an
> example from the R documentation for the uniroot routine.
>
> http://stat.ethz.ch/R-manual/R-patched/library/stats/html/uniroot.html
>
> The second example tries to find the smallest x for which exp(x) is
> computationally positive. So, here it goes in sympy...
>
>
> Python 2.5.4 console for SymPy 0.6.5
>
> These commands were executed:
>>>> from __future__ import division
>>>> from sympy import *
>>>> x, y, z = symbols('xyz')
>>>> k, m, n = symbols('kmn', integer=True)
>>>> f, g, h = map(Function, 'fgh')
>
> Documentation can be found at http://sympy.org/
>
> In [1]: F = Eq(1e80*exp(x) - 1e-300)
>
> In [2]: F
> Out[2]:
>                     x
> -1.0e-300 + 1.0e+80*e  = 0
>
> In [3]: tsolve(F,x)
> Out[3]: [log(1.0e-380)]
>
>
> Is there a way to specify the domain to search over? It looks like I
> can do this with solve (without an effect though) but can't with
> tsolve...
>
> In [5]: solve(F,x, domain=[-1000,0])
> Out[5]: [log(1.0e-380)]
>
> In [6]: tsolve(F,x, domain=[-1000,0])
> ---------------------------------------------------------------------------
> TypeError                                 Traceback (most recent call
> last)
>
> TypeError: tsolve() got an unexpected keyword argument 'domain'

as I understand, tsolve returns all roots. If it doesn't, it's a bug.
What is the correct solution that you expect from your computation
above?

Ondrej

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