How to plot and calculate these area under the curve

Hello,

I've a set of data x and y, that give me a figure below

x = [0.02	 0.07	  0.18	0.37	  0.56	0.68	  0.73	0.76	   0.80	0.83	   0.88	0.94	 1.00	1.06	   1.13    1.17	1.20	  1.24   1.27    1.32	1.44	 1.64   1.88 2.20];
y = [1.011   1.011  1.011   1.006	0.976	0.931   0.907	0.890    0.874	0.859	0.839	0.817	0.809	0.816	0.836	0.855    0.870	0.887   0.904	0.930   0.975	1.003	1.006    1.005];

I would like to calculate the area in red, grey and yellow. The code that I am using cannot distinguish between the areas above and below (i-e y = 1) and miscalculating it

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level = 1;
lineStart = find(y<=level,1);
lineEnd = find(y(lineStart:end)>=level,1)+lineStart;
plot(x,y)
hold all
area(x(lineStart:lineEnd),y(lineStart:lineEnd),level)
line([x(lineStart),x(lineEnd)],[level level])
hold off
grid
A = trapz(x(lineStart:lineEnd),y(lineStart:lineEnd))

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Any help or suggestion is appreciated !!

[dpb]

See

doc polyarea