[R] need help in using Hessian matrix

Hi I need to find the Hessian matrix for a complicated function from a certain kind of data but i keep getting this error Error in f1 - f2 : non-numeric argument to binary operator the data is given by U-runif(n) Us-sort(U) tau1- 2 F1tau-

[R] intigrate function and absolute error

Hi Can we get the result of an intigration without the absolute error? for example f1-function(x1){(1/gamma(alpha))*x1^(alpha-1)*exp(-x1)*log(x1)} I1-integrate(f1, 0, (max(cc)-tau1+(theta2/theta1)*tau1)/theta2) I1 0.08007414 with absolute error 7.2e-05 I need the answer 0.08007414 withou the