HP Forums

hi,
this code doesn't run:

Code:

minor();

EXPORT cofactors(m)

BEGIN

local tempmat, cofact, r, c, j, k;

  r:=rowDim(m);

  c:=colDim(m);

  cofact:=  MAKEMAT(0,r,c);

  tempmat:= m;

  FOR j FROM 1 TO r DO

    FOR k FROM 1 to c DO

      cofact:= minor(tempmat, j, k);

      tempmat(j,k):= cofact;

    END; // inner for

  END; //for

  RETURN tempmat;

END;

minor(mat, r,c)

BEGIN

  mat:= delrows(mat,r);

  mat:= delcols(mat,c);

  RETURN mat;

END;

EXPORT adj(m)

BEGIN

local ad;

  ad:= cofactors(m);

RETURN TRN(ad);

END;

Is it not possible to have a matrix as item od another matrix?

I think the problem is in the line < tempmat(j,k):= cofact; >, in fact...
Any help?

Salvo

ok, found!

this should run.
It returns both cofactors and adj (adjoint, transpose of cofactors):

Code:

minor();

EXPORT cofactors(m)

BEGIN

local tempmat, cofact, deter;

local r, c, j, k;

  r:=rowDim(m);

  c:=colDim(m);

  cofact:=  MAKEMAT(0,r,c);

  tempmat:= m;

  FOR j FROM 1 TO r DO

    FOR k FROM 1 to c DO

      cofact:= minor(m, j, k);

      deter:= ((-1)^(j+k)) * det(cofact);

      tempmat(j,k):= deter;

    END; // inner for

  END; //for

  RETURN tempmat;

END;

minor(mat, r,c)

BEGIN

  mat:= delrows(mat,r);

  mat:= delcols(mat,c);

  RETURN mat;

END;

EXPORT adj(m)

BEGIN

local ad;

  ad:= cofactors(m);

RETURN TRN(ad);

END;

salvomic

salvomic