Got it. I'm a college chemistry professor, just terrible at math solvers :)
I've found where I can find answers to those types of questions now. Thanks
again!
On Friday, September 22, 2017 at 8:51:38 AM UTC-5, Emmanuel Charpentier
wrote:
>
>
> Le vendredi 22 septembre 2017 15:42:40 UTC+2, Natalie Ulrich a écrit :
>>
>> That is extremely helpful. Many thanks, and have a beautiful day!
>>
>
> Thanks !
>
> Two notes :
>
> 1. This kind of question, which is more oriented at learning how to
> use Sage than at reporting a problem with it or suggesting a new
> development, is probably more useful when asked on ask.sagemath.org
> 2. Most potential answerers, being scholars/teachers/etc.., are wary
> of "homework" questions, and won't answer them (maybe providing helpful
> hints). Giving the context of the question and showing what parts of the
> work you did yourself may help them choosing the right answer...
>
>
> HTH,
>
> --
> Emmanuel Charpentier
>
>
>>
>> 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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