Stacked Area Graph

[feetimo]

I am trying to plot a series of regions ("passes") that represent a polygon. All regions are defined by a set of X and Y data that define their border. Each polygon region is a continuum...i.e. although on polygon one there is a y-value of 0 at x=8.0 and a y-value of 0.35 at x=7.25, it is assumed that this defines a sloping edge to the polygon.

This would not be a problem to plot (using a line chart, for example), except that I need the polygons to be "stacked". A stacked area chart gives an idea of what I need--however, an area chart does not have the capability for a numeric X-axis. I show 2 polygons here, but the spreadsheet has the capability of producing up to 8 polygons. Each one may have up to 40 "points" that define its shape.

End result would be a series of shaded (filled) areas that show. Chart would be fixed on a worksheet (NOT a seperate chart worksheet but on an existing one) with the source data being variable--perhaps each x,y data for each polygon in it's own set of columns?

VBA is OK to use, too, as much of the data is generated by VBA.

-Tim
(data is below)

Polygon One
x y1
8.00 0.00
7.25 0.35
6.40 0.75
-7.85 0.75
-9.00 0.50
-10.00 0.30
-13.20 0.25
-14.00 0.00

Polygon Two
x y2
-7.90 0.00
-7.15 0.38
-6.40 0.75
-4.80 0.75
-3.80 0.69
-2.80 0.63
-1.80 0.55
1.80 0.55
2.80 0.63
3.80 0.69
4.80 0.75
6.40 0.75
7.25 0.73
8.00 0.70
9.00 0.50
10.00 0.30
13.20 0.25
14.00 0.00

 

[Steve=True]

Jon has a great post on this topic

http://peltiertech.com/WordPress/fill-below-an-xy-chart-series-xy-area-combo-chart/


Steve=True
www.exceldashboardtemplates.com

 

[feetimo]

Interesting...but it looks as though I am still stuck on using the same "X" values for both areas. My "X"'s are different for each polygon area.

-Tim

 

[Jon Peltier]

You have many of the same X values, and you can interpolate where needed.

List all your X values with corresponding Y1 or Y2 values:

    x     y1     y2
  -14      0       
-13.2   0.25       
  -10    0.3       
   -9    0.5       
 -7.9             0
-7.85   0.75       
-7.15          0.38
 -6.4          0.75
 -4.8          0.75
 -3.8          0.69
 -2.8          0.63
 -1.8          0.55
  1.8          0.55
  2.8          0.63
  3.8          0.69
  4.8          0.75
  6.4   0.75   0.75
 7.25   0.35   0.73
    8      0    0.7
    9           0.5
   10           0.3
 13.2          0.25
   14             0

Interpolate where necessary (in blue):

    x     y1     y2
  -14      0       
-13.2   0.25       
  -10    0.3       
   -9    0.5       
 -7.9  0.739      0
-7.85   0.75  0.025
-7.15   0.75   0.38
 -6.4   0.75   0.75
 -4.8   0.75   0.75
 -3.8   0.75   0.69
 -2.8   0.75   0.63
 -1.8   0.75   0.55
  1.8   0.75   0.55
  2.8   0.75   0.63
  3.8   0.75   0.69
  4.8   0.75   0.75
  6.4   0.75   0.75
 7.25   0.35   0.73
    8      0    0.7
    9           0.5
   10           0.3
 13.2          0.25
   14             0