About matrix...



Patrick Gelin wrote:
> Raymond Toy wrote:
> 
>> nullspace(A)
> 
> ok, I tried nullspace(A) with my matrix:
> 
> (%o11) matrix([-2,-5,8,0,-17],[1,3,-5,1,5],[3,11,-19,7,1],[1,7,-13,5,-3]
> (%i12) nullspace(%);
> (%o12) span(matrix([0],[1],[1/5],[-1],[-1/5]),matrix([1],[0],[-3/5],[-2]
> [-2/5]))
> 
> maxima find out a different solution of my book! this is the solution of my
> book:
> 
>         [-1]    [-1]
>         [2]     [-3]    
> {       [1],    [0]     }
>         [0]     [5]
>         [0]     [1]

If you look carefully, you'll see that maxima's answer is equivalent to 
the text book answer.  The first column is 2*span1-span2 and the second 
column is -3*span1-span2, where span1 and span2 are the two columns 
given by maxima.
> 
> 
> By the way I need the reduced form too and not only the null space...

Ok.  I don't know if maxima already has a function for the reduced form. 
  It shouldn't be two hard to get, though.

Ray