# Revision history [back]

### Eigenspaces of a matrix defined on GF(2)

what is wrong with the eigenspaces method here? thank you for your help

MS=MatrixSpace(GF(2),16,16)
A=MS([
[1,0,1,1,0,0,0,1,0,0,0,0,0,0,0,1],
[1,0,0,0,1,1,0,1,1,0,0,0,0,0,0,0],
[0,1,0,0,1,1,1,0,0,1,0,0,0,0,0,0],
[0,0,1,0,0,1,1,1,0,0,1,0,0,0,0,0],
[0,0,0,1,1,0,1,1,0,0,0,1,0,0,0,0],
[0,0,0,0,1,0,0,0,1,1,0,1,1,0,0,0],
[0,0,0,0,0,1,0,0,1,1,1,0,0,1,0,0],
[0,0,0,0,0,0,1,0,0,1,1,1,0,0,1,0],
[0,0,0,0,0,0,0,1,1,0,1,1,0,0,0,1],
[1,0,0,0,0,0,0,0,1,0,0,0,1,1,0,1],
[0,1,0,0,0,0,0,0,0,1,0,0,1,1,1,0],
[0,0,1,0,0,0,0,0,0,0,1,0,0,1,1,1],
[0,0,0,1,0,0,0,0,0,0,0,1,1,0,1,1]])

p=A.charpoly()
p.factor()


(x + 1)^16

A.eigenspaces()


Traceback (most recent call last): File "<stdin>", line 1, in <module> File "_sage_input_19.py", line 10, in <module> exec compile(u'open("___code___.py","w").write("# -- coding: utf-8 --\n" + _support_.preparse_worksheet_cell(base64.b64decode("QS5laWdlbnNwYWNlcygp"),globals())+"\n"); execfile(os.path.abspath("___code___.py")) File "", line 1, in <module>

File "/private/var/folders/gm/z065gk616xg6g0xgn4c7_bvc0000gn/T/tmpZNvlMy/___code___.py", line 2, in <module> exec compile(u'A.eigenspaces() File "", line 1, in <module>

File "sage/structure/element.pyx", line 413, in sage.structure.element.Element.__getattr__ (/Applications/SageMath/src/build/cythonized/sage/structure/element.c:4531) File "sage/structure/misc.pyx", line 259, in sage.structure.misc.getattr_from_other_class (/Applications/SageMath/src/build/cythonized/sage/structure/misc.c:1771) AttributeError: 'sage.matrix.matrix_mod2_dense.Matrix_mod2_dense' object has no attribute 'eigenspaces'

A.rank()


16

### Eigenspaces of a matrix defined on GF(2)

what is wrong with the eigenspaces method here? thank you for your help

MS=MatrixSpace(GF(2),16,16)
MS=MatrixSpace(GF(2),16,16)

A=MS([
[1,1,0,1,1,0,0,0,0,0,0,0,1,0,0,0],
[1,1,1,0,0,1,0,0,0,0,0,0,0,1,0,0],
[0,1,1,1,0,0,1,0,0,0,0,0,0,0,1,0],
[1,0,1,1,0,0,0,1,0,0,0,0,0,0,0,1],
[1,0,0,0,1,1,0,1,1,0,0,0,0,0,0,0],
[0,1,0,0,1,1,1,0,0,1,0,0,0,0,0,0],
[0,0,1,0,0,1,1,1,0,0,1,0,0,0,0,0],
[0,0,0,1,1,0,1,1,0,0,0,1,0,0,0,0],
[0,0,0,0,1,0,0,0,1,1,0,1,1,0,0,0],
[0,0,0,0,0,1,0,0,1,1,1,0,0,1,0,0],
[0,0,0,0,0,0,1,0,0,1,1,1,0,0,1,0],
[0,0,0,0,0,0,0,1,1,0,1,1,0,0,0,1],
[1,0,0,0,0,0,0,0,1,0,0,0,1,1,0,1],
[0,1,0,0,0,0,0,0,0,1,0,0,1,1,1,0],
[0,0,1,0,0,0,0,0,0,0,1,0,0,1,1,1],
[0,0,0,1,0,0,0,0,0,0,0,1,1,0,1,1]])

 p=A.charpoly()
p.factor()


(x + 1)^16

A.eigenspaces()


Traceback (most recent call last): File "<stdin>", line 1, in <module> File "_sage_input_19.py", line 10, in <module> exec compile(u'open("___code___.py","w").write("# -- coding: utf-8 --\n" + _support_.preparse_worksheet_cell(base64.b64decode("QS5laWdlbnNwYWNlcygp"),globals())+"\n"); execfile(os.path.abspath("___code___.py")) File "", line 1, in <module>

File "/private/var/folders/gm/z065gk616xg6g0xgn4c7_bvc0000gn/T/tmpZNvlMy/___code___.py", line 2, in <module> exec compile(u'A.eigenspaces() File "", line 1, in <module>

File "sage/structure/element.pyx", line 413, in sage.structure.element.Element.__getattr__ (/Applications/SageMath/src/build/cythonized/sage/structure/element.c:4531) File "sage/structure/misc.pyx", line 259, in sage.structure.misc.getattr_from_other_class (/Applications/SageMath/src/build/cythonized/sage/structure/misc.c:1771) AttributeError: 'sage.matrix.matrix_mod2_dense.Matrix_mod2_dense' object has no attribute 'eigenspaces'

A.rank()


16