Problem with the minus sign in symbolic expression
My sage version is:
'SageMath Version 6.9, Release Date: 2015-10-10'
In my code, I have a multivariate polynomial with a sign symbol which doesn't return the correct result. I.e.
The code snippet is as follows:
A1 = [(', '.join('x%i'%i for i in [1.. n]))]; ### construct a suitable multivariate ring V = var(A1) ### define a str variable x=vector(list(V)) ### convert to vector f1=b1-a1.dot_product(x)
a1 and b1 are returned from another function.
types of a1 and x are different:
type(a1)=<type 'sage.modules.vector_modn_dense.Vector_modn_dense'> type(x)= <class 'sage.modules.vector_symbolic_dense.FreeModule_ambient_field_with_category.element_class'>
Could this be a problem?
a1 is a vector with values (76, 83), b1 is scalar with value 62, x is a vector with values (x1,x2). Thus, f1 should return 62-76 * x1-83 * x2; however it returns 25x1 + 18x2 + 62 which is not correct.
Please note that if I use addition in f1 as follows:
The result is correct,i.e. 76x1 + 83x2 + 62
type(f1) is sage.symbolic.expression.Expression
What could the problem be? I tried to convert the symbolic expression to multivariate polynomial, but this didn't work either? I also though there might be a problem with the minus symbol in my PC but couldn't solve it this way either.
Thank you for your responses! Regards, Natassa