[R] Search zeros of one function

2007-03-22 Thread enrico\.foscolo
Dear participants to the list, this is my problem: I want to find zeros of an arbitrary function. With uniroot (package stats) it is possible to find (numerically) a root of the function, but I do not know how I can find at the same time the zeros in a determined interval (if this function must

[R] Problems about Derivaties

2007-03-20 Thread enrico\.foscolo
Dear participants to the list, this is my problem: I want to obtain an expression that represents the second derivative of one function. With deriv3 (package stats) it is possible to evaluate the second derivative, but I do not know how I can get the (analytical) expression of this derivative.