calculate derivative from a data set

I have a data set with about 450 values, and now i need the second derivative from the function that comes out of the data set. Is there a way to do this in libreoffice calc?

You surely know that a function, say f: x → y assumed to be applicabhle to a continuous range of abscissae cannot be defined by a finite set of pairs (x, y) generally.
Mostly you also will not expect your pairs to match the function exactly. You will instead look for a function being member of a specific family and approximating your set of pairs with sufficient accuracy.
If you have “a theory” assuring the exemplified function to be a member of a specific family, you will describe the family using parameters, and then calculate a set of parameter values optimising the approximation in a specific sense based on your set of pairs.
An approximating function found this way can be differntiated one or more times relying on the rules you were teached. The resulting functions may then be evaluated for specific abscissae in a spreadsheet if it provides the needed standard functions.

Another approach (often used in practical control engineering) is to omit the search for an approximation by a function, and to take the pairs of values to calculate the difference quotients ( (f(x2) - f(x1)) / (x2 - x1) ) as a “surrogate” for the values of the first order derivative. This is very easy in a spreadsheet, but of limited value.
In principle you can iterate this getting higher order difference quotients, but the results will often be “extremely nervous” and rarely usable in engineering.
There are more sophisticatd methods concerning this “numerical differentiation”. See this wikipedia page for an introduction.

You see, your question is rather one of mathematics than one of spreadsheet usage. More detailed advice (also concerning spreadsheets insofar) depends on details of your task.

Totally agree. See this link for a discussion of numerical differentiation and its problems.

Possibly try using the LINEST function to get a polynomial curve fit to your data. Note that LINEST returns an array so formula should be entered with ctrl-shift-Enter and the result will occupy a range of cells.

Link to OpenOffice description of LINEST will possibly help you decide if this is what you were looking for.

link text