Functions and commands 383
delcols Returns the matrix that is matrix A with the columns n1...nk
deleted.
delcols(Mtrx(A),Interval(n1...nk)||n1)
Example:
delcols([[1,2,3],[4,5,6],[7,8,9]],1..1) gives
[[1,3],[4,6],[7,9]]
delrows Returns the matrix that is matrix A with the rows n1...nk
deleted.
delrows(Mtrx(A),Interval(n1..n2)||n1)
Example:
delrows([[1,2,3],[4,5,6],[7,8,9]],1..1) gives
[[1,2,3],[7,8,9]]
deltalist Returns the list of the differences between consecutive terms in
the original list.
deltalist(Lst)
Example:
deltalist([1,4,8,9]) gives [3,4,1]
Dirac Returns the value of the Dirac delta function for a real number.
Dirac(Real)
Example:
Dirac(1) gives 0
division_point Returns a point M such that for the given a and b,
(z–a)=k*(z–b) and z=MA=k*MB.
division_point(Pnt or Cplx(a),Pnt or
Cplx(b),Cplx(k))
Example:
division_point(0,6+6*i,4) returns point (8,8)
DO Used in programming to initiate a step or sequence of steps.
DrawSlp Draws the line with slope m that goes through the point (a,b)
(i.e. y–b=m(x–a)).
DrawSlp(Real(a),Real(b),Real(m))
Example:
DrawSlp(2,1,3) draws the line given by y=3x–5