RemoveSpin

Matrix.RemoveSpin(M) removes all even columns and even rows of matrix M.

Example.Quanty

M = Matrix.New({{1,0,2,0},
                {0,1,0,2},
                {3,0,4,0},
                {0,3,0,4}})
S = Matrix.RemoveSpin(M)
print(M)
print(S)

{ {  1      ,  0      ,  2      ,  0      } ,
  {  0      ,  1      ,  0      ,  2      } ,
  {  3      ,  0      ,  4      ,  0      } ,
  {  0      ,  3      ,  0      ,  4      } }
 
{ {  1      ,  2      } ,
  {  3      ,  4      } }