Dear LabView users, I need to calculate first and second derivatives of a signal (experimental data acquired in function of time).
I ask you to confirm to me, that the piecewise polynomial as given by the Spline Interpolation 1D VI contains the coefficients of the polynomial
a(x-xi)^3 + b(x-xi)^2 + c(x-xi) + d
and not the coefficient of the polynomial
ax^3 + bx^2 + cx + d
If so, c and 2b should be, respectively, the first and the second derivatives evaluated at the current point xi.
Please, let me know if I am right.