Area between function and polyline

Hi everyone I have a problem. I try to calculate the area between a linear function (red) and a polyline (blue). I hope someone can help me.

Answer 1

[Jan]

How are the values of the lines stored? In two vectors containing Y values to the the same X coordinates? If so:

match = (y_blue <= y_red);
Area  = cumtrapz(y_red(match) - y_blue(match))

[An Ku]

Thank very much. :) May you have an idea how I can visualize this area in a plot?