[Octave-bug-tracker] [bug #53321] Symbolic creates an oversize ( ), multiplication is not carried out appropriately

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?53321>

                 Summary: Symbolic creates an oversize ( ), multiplication is
not carried out appropriately
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Sun 11 Mar 2018 08:44:32 AM UTC
                Category: Octave Forge Package
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: None
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.2.1
        Operating System: GNU/Linux

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Details:

Using:
symbolic v2.6.0
sympy v1.1.1 

Doing the following:


syms l b a d 
X_p=[cos(l)*cos(b);sin(l)*cos(b); sin(b)];
X=[cos(a)*cos(d);sin(a)*cos(d); sin(d)];
R_mat=X_p*X';
S_mat=X*X_p';


R_mat and S_mat gives values with ()'s and large ()'s

This presents a problem when trying:


S_mat*X_p


Since it cannot tell that sin(b) and sin large (b) are the same
the multiplication does not become sin^2(b)





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