Area charts with smooth lines?

[coldcanuck]

I'm trying to plot two sets of data on one chart - the first represents revenue forecasts and are plotted against the secondary axis and the second set represents the confidence interval and is plotted against the primary access. In order to shade in the confidence interval, I plotted the two sets of data using stacked area charts. The revenue forecasts are smoothed line charts.

The problem I'm facing is that the area chart function does not have the capability to smooth the top. It seems this is a common problem. Does anyone have a solution to this common problem? Area charts are the only way I know to fill in between two lines.

Sample file here.

 

[Jon Peltier]

My answer has two parts:

1. Area charts do not support smoothed lines. You could subdivide the data and determine where the smoothed data goes, which is a bit of a chore. Brian Murphy has posted a file that helps make these calculations at http://www.xlrotor.com/Smooth_curve_bezier_example_file.zip.

2. Smoothed lines make a chart look "nicer" at the risk of making the chart tell lies. I describe the problem in Smooth Talking Lies.

 

[coldcanuck]

My answer has two parts:

1. Area charts do not support smoothed lines. You could subdivide the data and determine where the smoothed data goes, which is a bit of a chore. Brian Murphy has posted a file that helps make these calculations at http://www.xlrotor.com/Smooth_curve_bezier_example_file.zip.

I don't see how Mr. Murphy's solution is any more than creating a smoothed line graph. And how would I add fill between two Bezier curves?

2. Smoothed lines make a chart look "nicer" at the risk of making the chart tell lies. I describe the problem in Smooth Talking Lies.

Your point is well taken. However, this chart is for the CEO of a billion dollar company, so it's more eye candy and precision planning.

 

[Jon Peltier]

However, this chart is for the CEO of a billion dollar company, so it's more eye candy and precision planning.

Maybe you should be using Microsoft Paint (ha ha).

 

[DanielAlgolux]

Well, had this problem for a similar situation (marketing document), and it was all going haywire. I figured, might as well draw it.

Problem solved, took 2 minutes.