Kite Diagrams?

Ken,

What have you tried so far and what didn't you like about the result?

Jerry

If I undertand what you are looking for, plotting an area diagram of

1) Your data as one series and
2) The negative of your data as another series and
3) Setting the two colors the same

will give a kite-like diagram of a single data set. Is that what you've done so far? Multiple data sets would require a different method.

Can you post a screen shot or image of what you are looking to do?

badunit,

The way I get it is that the method is generally used to compare two sets of similar data, so for instance, sample set one would be plotted above the line and sample set two would be plotted below the line, producing a somewhat mirror image. I don't know what the advantage is, but it seems to be popular in the life sciences.

Jerry

The ones I saw online were actual mirror images with "species presence recorded around an invisible central axis to produce a series of kite-like shapes which show species fading in and out along the transect."

This is easy to do with a single data set using Y=0 as the central axis. To create a single series above the zero line is still pretty easy using a stacked area chart and some simple math. Getting two or more series on a chart I have not figured out other than with overlying charts.

For a single series, you could plot Y and -Y on an Area Chart, then just set the colors the same for both halves.

Jerry

That's what I was describing in my first post. I've also seen kite diagrams where the X axis wasn't the centerline. But it's easy to make any arbitrary line the center line. It requires charting two columns of transformed data on a stacked area chart with the one data set set to no fill color.

Badunit wrote:
That's what I was describing in my first post.

Missed that, sorry.

For multiples, I'd just turn off everything but the series, make one chart for each data set and stack them up.

You can draw your own lines and lay in the titles.

Jerry

This is two overlaid charts. Is that close to what you're looking for?

Column C =200-B
Column D = 2*B
Column F = 80-E
Column G = 2*E

I created a stacked bar chart for C&D and another for F&G. The two series corresponding to C and F I set to no fill in the Graphic Inspector. I removed most of the elements of the second chart, set the chart fill color to none, ensured the two charts had the same max Y value on the axis (before hiding the Y axis value labels), made sure the two charts were the same size, and did a few other things then slid the second chart over the first. Kind of a pain but this is the result.

I would recommend having a table with the data and another table for the mathematical manipulations and use the second table for creating the chart(s). That's not what I did but I recommend doing it that way. There are also other ways you could manipulate the data and make and overlay charts. You could just chart +/-Y data on multiple charts and overlay them so the Y axis aligns on each but the X axis does not and have one blank chart in there to provide the X and Y axis.

I tried it with +/-Y charts overlaid on each other. One problem is that it leaves a thin white line down the centerline of the kites. It also didn't seem quite as easy and I could not use the chart legend because the second series in each chart (the -Y data) shows up as an extra colored square in the legend.