Can any one suggest me how to use coordinate transformation in the calculation of second order derivative of a function just like the use of Jacobian matrix in the calculation of first order derivatives? Please help
If x (r, th) =r cos (r,th) and y (r,th) = r sin(th). The Jacobian of the transformation is
[ [ cos(th), -rsin(th)], [ sin(th), r cos(th) ]]. Given a function f(x,y) of x and y, in new coordinates r, th the value of fr = fx cos(th) + fy sin(th), fth =fx .(-r sin(th)) + fy r cos(th).
Now, frr = ( fx cos(th) + fy sin(th))x cos(th) +( fx cos(th) + fy sin(th))y sin(th)
If you know how to express first order derivatives in these coordinates, you just use this sequentially. In this way, for instance the Laplacian in curvilinear coordinates is found by calculating the divergence of a gradient. See wikipedia (link below) and Laplacian in curvilinear coordinates (e.g., see 2nd link below).
If x (r, th) =r cos (r,th) and y (r,th) = r sin(th). The Jacobian of the transformation is
[ [ cos(th), -rsin(th)], [ sin(th), r cos(th) ]]. Given a function f(x,y) of x and y, in new coordinates r, th the value of fr = fx cos(th) + fy sin(th), fth =fx .(-r sin(th)) + fy r cos(th).
Now, frr = ( fx cos(th) + fy sin(th))x cos(th) +( fx cos(th) + fy sin(th))y sin(th)
Similarly I need to calculate the relation between {∂2 N/∂x2 ; ∂2 N/∂y2 } and {∂2 N/∂u2 ; ∂2 N/∂v2 } something like {∂2 N/∂x2 ; ∂2 N/∂y2 } = [a matrix]* {∂2 N/∂u2 ; ∂2 N/∂v2 } . Is this possible? Or how to evaluate this? Please be more specific.
Answer to your original question is , you may see as given above. For reference you may see a good book on differential calculus or Schaum Series. If you want form for [ ∂ 2N/∂x2, ∂2N/∂y2 ]t = J-1[∂/∂u), ∂/∂v ]t J-1 [∂N/∂u),∂N/∂v ]t .