Adding median lines to xy scatter graph

**Richard Buttrey** · 10-18-2008, 03:04 PM

Hi,

This is probably one for Andy, but ideas welcome from all.

I have two sets of data (i.e. several rows and two columns), both with values in the range 0 - 1. I'm plotting these on an xy scatter chart

The two median values for these two sets of data now need to be plotted on the chart as two lines, one horizontal and one vertical, effectively dividing the chart into 4 quadrants.

At the moment I've been achieving this functionality somewhat artificially, by superimposing 4 rectangle objects on the chart and adjusting their dimensions manually to coincide with the two median values on the two axes.

In addition I've been manually adding two text boxes each containing one of the median values and positioning it next to the appropriate median 'line'.

My question is this.

Is there a neater way of achieving this functionality without the somewhat artificial method of resorting to overlaid rectangles?

I can adjust the 4 rectangles programatically by changing the height and width property, but the text box needs to be positioned and there doesn't appear to be a Top and Left property.

All ideas gratefully received. Usual TIA

**shg** · 10-18-2008, 03:39 PM

Why not add two series, each with two points?

xmed, ymin
xmed, ymax

xmin, ymed
xmax, ymed

**Richard Buttrey** · 10-18-2008, 04:52 PM

Hi shg,

Good lateral thinking I'll give that a whirl.

Ah, just remembered that it's the individual x,y plots that are the relevant factor here - hence the x,y scattergraph. A straight forward series plot wouldn't achieve that.

One of the other requirements was to have two different fill colours for the top right hand and bottom left quadrants - hence the artificial use of overlaid rectangles.

Any thoughts on that aspect?

Regards

**shg** · 10-18-2008, 06:12 PM

A straight forward series plot wouldn't achieve that.

Wouldn't achieve what?

One of the other requirements was to have two different fill colours for the top right hand and bottom left quadrants - hence the artificial use of overlaid rectangles.

Create a picture having the desired quadrant colors using your favorite draw program, and then use it to fill the plot area:

Format > Selected Plot Area, Fill Effects, Select Picture ...

**Richard Buttrey** · 10-19-2008, 02:31 AM

Sorry, didn't explain that well enough. The two series lines would just plot a line, or points for each series. What's needed is the co-ordinate plot of each pair of values.

As for the rectangles, if you think of the whole chart area, it will be dotted with plotted points. Each of the two series has a median value. Those two median values need to be used to somehow divide the chart into 4 quadrants, by adding the median lines perpendicular to both the x & y axes. The upper right and lower left quadrants thus formed need to have a coloured background.

I've been using overlaid rectangles to achieve this, but manually dragging the borders to the appropriate points on the chart. I know I can do this programmatically, I just wondered if there was any chart functionality that would achieve the same thing. The other requirement is to position two text boxes, each of which contains the text "Median = 23" (or whatever the median value is), close to the median line.

Thanks for your input.

Regards

**Andy Pope** · 10-19-2008, 07:03 AM

Can you post example of your data set and if possible one that has the autoshapes to provide colour and labeling.

It's certainly possible to use additional series to draw the quadrents and even hold Median information. The biggest problem is the colouring of sectors.
This is not an automatic feature in Windows, although I think the Mac version can do filled xy-scatters.

Would a coded solution be usable?