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Hi all!

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:

sage: f1=b1-a1.dot_product(x)

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:

sage: f1=b1+a1.dot_product(x)

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

Hi all!

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:

sage: f1=b1-a1.dot_product(x)

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:

sage: f1=b1+a1.dot_product(x)

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

Hi all!

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: follows:

A1 = [(', '.join('x%i'%i for i in [1.. n]))]; ### construct a suitable multivariate ring
  V = var(A1[0])                               ### define a str variable
 x=vector(list(V))                                 ### convert to vector
    f1=b1-a1.dot_product(x)  
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 cause 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:

sage: f1=b1+a1.dot_product(x)

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

Hi all!

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[0])                               ### 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 **types of a1 and x are different different:

type(x)=  <class 'sage.modules.vector_symbolic_dense.freemodule_ambient_field_with_category.element_class'="">
'sage.modules.vector_symbolic_dense.FreeModule_ambient_field_with_category.element_class'>

Could this cause a problem?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:

sage: f1=b1+a1.dot_product(x)

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

Hi all!

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[0])                               ### 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 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 cause a problem?**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:

sage: f1=b1+a1.dot_product(x)

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

Hi all!

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[0])                               ### 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(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:

sage: f1=b1+a1.dot_product(x)

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