How to plot graph of 2 list plots?

Question

I have two Listsoflist containing x and y coordinates. Now, I want to plot the two profiles, show their intersection and find the area of each intersecting region. I have used interpolating function to find the plots but unable find intersection point.

Can you please provide us with the two lists, so that we can use them in the answer? — Fraccalo, Aug 22 '18 at 18:33
Then create a fake test case for us that has the same structrure, but is smaller. — Marius Ladegård Meyer, Aug 22 '18 at 19:20
This is one of your first posts and I'm going to create data for you, but you should really provide a sample of your data for allowing SE community to help you with your problem. — Fraccalo, Aug 22 '18 at 19:28

score 3 · Accepted Answer · answered Aug 22 '18 at 19:26

Creating fake data for example

list1 = {Range[20],Join[Range[10] + RandomReal[1, 10],10 - Range[10] + RandomReal[1, 10]]}//Transpose;
list2 = {Range[20],Join[10 - Range[10] + RandomReal[1, 10], Range[10] + RandomReal[1, 10]]}//Transpose;

Interpolating them:

f1 = Interpolation[list1];
f2 = Interpolation[list2];

Finding intersections:

roots = {FindRoot[f1[x] - f2[x] == 0, {x, 5}], 
   FindRoot[f1[y] - f2[y] == 0, {y, 15}]} // Flatten

{x -> 5.12575, y -> 14.9835}

Showing the plot:

Show[
 ListLinePlot[{list1, list2}, 
  Filling -> {2 -> {{1}, {LightBlue, Transparent}}}]
 ,
 ListPlot[{{x, f1[x]}, {y, f1[y]}} /. roots, PlotStyle -> Blue]
 ]

Integrating for finding the area:

NIntegrate[f1[z] - f2[z], {z, x, y} /. roots]

50.5077

How to plot graph of 2 list plots?

1 Answers1