You could take a look at Theano, a project similar to SymPy but devoted to numeric computation on arrays. The sophistication of the simplifications is much lower but arrays are supported to a greater extent.
On Fri, Sep 6, 2013 at 12:13 AM, david <[email protected]> wrote: > @Stefan > You are right. The therms of the expressions have to be combined as much > as possible. This is more a pre evaluation as a simplification. Some > variables are changing during the repeating calculation of the expressions > afterwards. This variables are numpy arrays or normal floats and therfore > must be preserved in the expression. I have looked in many python libraries > but sympy simplification did what I want. Unfortunatly the syntax dont > supports the array style of variables and symbols. > The task you suggest with lambdify has to follow after the simplification. > Because even with lambdify you have to carry out much more operations than > necessary. > > Am Freitag, 6. September 2013 01:49:31 UTC+2 schrieb Aaron Meurer: >> >> As I suggested on the StackOverflow question, you might try using the >> matrix expressions. >> >> Aaron Meurer >> >> >> On Thu, Sep 5, 2013 at 2:53 PM, Stefan Krastanov <[email protected]>wrote: >> >>> Is there a reason not to use Symbols? From your explanations I do not >>> see one. If your issue is how to couple the result to something like numpy, >>> checkout `lambdify`. >>> >>> >>> On 5 September 2013 15:54, david <[email protected]> wrote: >>> >>>> For better explanation I have done the simplification in MatCad where >>>> unassigned variables are seen as symbols in sympy. >>>> >>>> >>>> <https://lh4.googleusercontent.com/-uq82CF7JYZw/UijhDNbjPvI/AAAAAAAAAAM/bPAnd8PQSpI/s1600/simplify+with++arrays.tiff> >>>> >>>> >>>> Am Donnerstag, 5. September 2013 15:19:14 UTC+2 schrieb david: >>>> >>>>> I have explored the sympy features and i was very impressed with both >>>>> the amount of features and the ease of testing with the doc and the >>>>> coupled >>>>> Live Shell. >>>>> I want to write a programm that simplifies expressions as much as >>>>> possible to minimize calculation time because they will later be >>>>> numericaly >>>>> evaluated very often. >>>>> The most features I need work very well. But with arrays I have a >>>>> problem. >>>>> I need to define an array object as an symbol, so that the following >>>>> is possible: >>>>> >>>>> simplify(2.0*2.0*t[0]) >>>>> is simplified to: >>>>> 4.0*t[0] >>>>> >>>>> and: >>>>> idx = 2 >>>>> simplify(2.0*2.0*t[idx]) >>>>> shold be simplified to: >>>>> 4.0*t[2] >>>>> >>>>> Is there any way to do this? >>>>> >>>>> david >>>>> >>>> >>>> -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
