I have a set of measurements of a variable over time. I have these measurements in a file called "results" with this format:

```
# time sample
0      5
12     43
234    342

```

etc...

I can easily plot this in gnuplot with:

```
plot "results"

```

Is there any way to plot the derivative of these measurements with regard to time (i.e. dsample/dt) directly from gnuplot, or do I have to calculate the derivative separately and plot *that* directly in gnuplot?