Shading area under a line

[Cynthia Inglesias]

Dear all

I am trying to shade the area under a line on a scatter plot but despite my best efforts i cannot seem able to make it work. I am using the following code to define the coordinates of the area i want shaded:

 twoway scatter ...  || scatteri  ... , msymbol(none) bcolor(black) recast(connected) lpattern(solid)

The result is illustrated on Figure 1. But when i change the recast option to "area" the graph gets messed up as Figure 2 shows. Apparently, my guess is that i have to define coordinates for every single point in order for this to work and again i am not sure.

I was wondering if there is a simpler way of doing this? Or does anyone have any ideas?

Thank you.

Cynthia

[Scott Merryman]

Do you mean something like this:

clear
input x y
0 0
1 0
1 1
0 0 
end
scatter y x , recast(line) || scatteri 0 0 0 .75 .75 .75 0 0 , recast(area)

[Cynthia Inglesias]

Hi Scott, thanks for this. The scatter plot and the line/area are separate. I just need to overlay them in one graph. Apologies, I should have been more specific:

 twoway scatter var1 var2  || line var3 var4 ///
 || scatteri  --> coordinates that bound the area (including the line) <--  , ///  
msymbol(none) bcolor(black) recast(connected) lpattern(solid)

But I want to shade all the area under the line kind off like you do. Do i have to specify all the coordinates? Isn't there a simpler way?

[Carole J. Wilson]

I'm not entirely sure what you want. Is it something like this?

sysuse auto, clear
collapse (mean) mpg price headroom trunk weight length turn, by(rep78)
twoway area trunk rep78 || scatter headroom rep78

Note that you want to draw the area graph in the first graph so that it is in the background and does not obscure the scatter (and/or line).

[Cynthia Inglesias]

Hi Carole, thanks for your suggestion. After playing around a bit, I have actually managed to do what i wanted by combining your examples: save the coordinates in variables and then using these in the right order in a twoway graph.