Percentile plots

[wsjinamesParticipant]

I am a new user, having switched from Kaleidagraph (which I used for what seems like 20 years…) when I finally gave up on them updating to 64 bit…so please pardon my naïveté.

So far I either think I can meet my scientific plotting needs or I can see where I have to go to figure things out… but my semester has just come to an end, and I can figure out how to do one of the fundamental types of plots I always found useful or at least interesting for my classes.

I have a single column with a few hundred scores from class (whether it’s a single exam or points overall…anything like that…doesn’t matter).  I can obviously make a histogram, but what I really want is to make a plot of “percentile within the data set” as the y axis and raw score as the X axis.  I have a column to supply the X data, obviously.  (This was a pre-fabbed probability-type plot in Kaleidagraph). Although I don’t grade on a curve, I do want students to easily be able to figure out how they did relative to their peers if they want to.

I’m willing to go few a few steps if I need to to build such a plot, but I don’t even know where to start.  It isn’t addressed in the manual or videos online to the extent I can find.  Can you point me in the right direction?

Thanks,
William

 

 

[dgteamModerator]

Thanks for trying out DataGraph 🙂  Asking here for help is a great way to start – as we try very hard to reply quickly.

I think what you are looking for is an option in the Histogram command. Like many of the commands they have a lot of options beyond what is created by default.

For example, say this is your default histogram based on grades, where you might want the bins in a specific increment.

Expand the command to reveal more options, such as below.

The graph can also be displayed as a cumulative distribution.

 

We added these examples to the on-line documentation for the Histogram command.

Please let us know if this is what you were looking for or if you want to customize the look in some way.

Note that once you create a custom graph command in DataGraph, they can be selected (command-C) and pasted (command-V)  into other files.  As long as the same column titles exist, the graph will be drawn.  Or you can use the menus to select the data in other files.

 

[wsjinamesParticipant]

Indeed, thanks.  That looks like it will do the trick!

I was pretty sure we had to be capable of this but I don’t know the software well enough yet to know all the little abbreviations and such to make it work.

Thank you!

[Author]

Posts