That is extremely helpful. Many thanks, and have a beautiful day!
On Friday, September 22, 2017 at 7:03:38 AM UTC-5, Emmanuel Charpentier
wrote:
> Even more Pythonish, and more direct (no conversions, Sage will take care
> of the (hairy !) exact arithmetics)...) :
>
> [s for s in solve([eq1, eq2, eq3],[x, y, z], solution_dict=True) if
> all(map(lambda t:bool(t>0), s.values()))]
>
> [{z: 1/200000*sqrt(2496889) - 83/200000,
> y: 1/200000*sqrt(2496889) - 83/200000,
> x: -1/200000*sqrt(2496889) + 15083/200000}]
>
> HTH,
>
> --
> Emmanuel Charpentier
>
> Le vendredi 22 septembre 2017 13:47:39 UTC+2, Emmanuel Charpentier a
> écrit :
>>
>> Some may find my first answer a bit Lispish. More Pythonish :
>>
>> [[s.lhs()==s.rhs().n() for s in S] for S in solve([eq1, eq2, eq3],[x, y,
>> z])]
>> [[x == 0.0675142263037092, y == 0.00748577369629076, z ==
>> 0.00748577369629076],
>> [x == 0.0833157736962908, y == -0.00831577369629076, z ==
>> -0.00831577369629076]]
>>
>> HTH,
>>
>> --
>> Emmanuel Charpentier
>>
>> Le vendredi 22 septembre 2017 13:40:45 UTC+2, Emmanuel Charpentier a
>> écrit :
>>>
>>> what's wrong with :
>>>
>>> map(lambda S:map(lambda s:s.lhs()==s.rhs().n(), S), solve([eq1, eq2,
>>> eq3], [x, y, z]))
>>>
>>> [[x == 0.0675142263037092, y == 0.00748577369629076, z ==
>>> 0.00748577369629076],
>>> [x == 0.0833157736962908, y == -0.00831577369629076, z ==
>>> -0.00831577369629076]]
>>>
>>> Which shows that the first solution fulfills your constraints ?
>>>
>>> HTH,
>>>
>>> --
>>> Emmanuel Charpentier
>>>
>>> Le jeudi 21 septembre 2017 20:27:43 UTC+2, Natalie Ulrich a écrit :
>>>>
>>>> I'm using SageMathCell to solve chemical equilibrium problems, so at
>>>> least one set of my solutions has to be real and positive.
>>>>
>>>> Here's my code:
>>>>
>>>> var('x, y, z')
>>>>
>>>> xi=0
>>>>
>>>> yi=0.150/2.0
>>>>
>>>> zi=0.150/2.0
>>>>
>>>> K=8.3e-4
>>>>
>>>> eq1=K == y*z/ x
>>>>
>>>> eq2=xi+yi==x+y
>>>>
>>>> eq3=2*xi+2*zi==2*x+2*z
>>>>
>>>> solve([eq1, eq2, eq3],[x, y, z])
>>>>
>>>>
>>>>
>>>> And here are my solutions:
>>>>
>>>> [[x == -1/200000*sqrt(2496889) + 15083/200000, y ==
>>>> 1/200000*sqrt(2496889) - 83/200000, z == 1/200000*sqrt(2496889) -
>>>> 83/200000], [x == 1/200000*sqrt(2496889) + 15083/200000, y ==
>>>> -1/200000*sqrt(2496889) - 83/200000, z == -1/200000*sqrt(2496889) - 83/
>>>> 200000]]
>>>> ------------------------------
>>>>
>>>>
>>>> Any thoughts? Thanks in advance.
>>>>
>>>>
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