[Tutor] question about pychart

[nephish]

Hey there,
i have a simple app that plots some numbers sent by a field sensor with
respect to time. i am trying to do this in pychart, but the problem is,
when the numbers come in, they do so at almost random times.
y shows the value sent by the sensor
x plots the time that the value came in.

what happens is that the plots are spaced evenly throughout the x axis.
so it always looks like an even amount of time when most often, it isn't
i need a way to make it plot out the x so that when a lot of values come
in at close to the same time, it looks more like that on the graph. i
looked at the docs where the examples show that this can be done, the
example uses a log style to the plot.
it looks like this.
http://home.gna.org/pychart/examples/scattertest.png

mostly the graph on the right

my chart shows just a plot of x=datetime y=value,
someone have an idea about how i can get more realistic looking values?

thanks 
shawn