Fill area under a curve

Is the right path to filling an area under a plot always area(X,Y)? Does it also work for more comlicated functions with hundres of plotting points?

[Dyuman Joshi]

Regardless the number of points in a plot, area() will fill the area under the plot.

x=0:0.0001:10;
y=50*sin(x).*cos(x)-25*sin(x)+75*cos(x);
fprintf('The number of points plotted below is %d', numel(x))

The number of points plotted below is 100001

area(x,y)

[John D'Errico]

@Nikola - since you already seem to know about area, why do you think it might not do what you want, since you seem to wonder if it will not work for you? Did you try something, and see something strange happen? Is there something confusing about the documentation for area that could perhaps be rectified? Please help us, so that we can better help you.

[Nikola]

Its alright now, I kinda figured it out with the help of the people that answered (the community is amazing btw). The only thing I dont like about the 'area' function is that it doesnt seem to color the edges of the bottom part of the area.. Is there any way I can fix that?

Answer 1

[Arka]

Hi,

Yes, you can use area to plot the area under the curves for functions. I was not sure what you meant by "complicated function", but I tried to demonstrate the example using a relatively complicated function and quite a few data points.

x = linspace(0,2, 10000000);
y = sqrt(x)+power(x, 1/3)+526.*sin(1./x);
area(x, y)

Answer 2

[Dyuman Joshi]

Coloring the edges at the bottom -

You might need to adjust y-limits to see the baseline properly in your figure.

x = 0:0.0001:10;
y = 50*sin(x).*cos(x)-25*sin(x)+75*cos(x);
p = area(x,y);

%Change the Line style of baseline
p.BaseLine.LineStyle = '--';
%Make baseline prominent
p.BaseLine.Color = [1 0 0];
p.BaseLine.LineWidth = 2.5;