Plot two areas of logarithmic plots

Hello there,

I have two parameters that I want to plot them in one graph with area (transparent/alpha mode) for each of them as follow:

Here is my initial script (line plots):

load('data_x.mat')

figure;
plot(x1,y,'b','Linewidth',1); 
hold on;
plot(x2,y,'r','Linewidth',1);
set(gca,'xscale','log','Ydir','reverse')

Warning: Negative data ignored

Does anyone know how to do that? Please find attached my data.

Thank you

Answer 1

[Voss]

load('data_x.mat')

figure;
plot(x1,y,'b','Linewidth',1); 
hold on;
plot(x2,y,'r','Linewidth',1);
set(gca,'xscale','log','Ydir','reverse')

x_lim = xlim();

Warning: Negative data ignored

x_p = x1;
x_p(~isfinite(x1) | x1 <= 0) = x_lim(1);
patch([x_p x_lim([1 1])],[y y([end 1])],'b','EdgeColor','none','FaceAlpha',0.25)

x_p = x2;
x_p(~isfinite(x2) | x2 <= 0) = x_lim(1);
patch([x_p x_lim([1 1])],[y y([end 1])],'r','EdgeColor','none','FaceAlpha',0.25)

[Adi Purwandana]

Great. Thank you!

Anyway, do you know how to add legend properly? I put this line but does not looking good...

legend('A','B')

It creates 4 items in the legend instead of two. Any suggestion?

[Voss]

You're welcome!

One way is to set the patches' HandleVisibility to 'off':

load('data_x.mat')

figure;
plot(x1,y,'b','Linewidth',1); 
hold on;
plot(x2,y,'r','Linewidth',1);
set(gca,'xscale','log','Ydir','reverse')

x_lim = xlim();

Warning: Negative data ignored

x_p = x1;
x_p(~isfinite(x1) | x1 <= 0) = x_lim(1);
patch([x_p x_lim([1 1])],[y y([end 1])],'b','EdgeColor','none','FaceAlpha',0.25,'HandleVisibility','off')

x_p = x2;
x_p(~isfinite(x2) | x2 <= 0) = x_lim(1);
patch([x_p x_lim([1 1])],[y y([end 1])],'r','EdgeColor','none','FaceAlpha',0.25,'HandleVisibility','off')

legend('A','B')

[Adi Purwandana]

Thank you!

[Voss]

You're welcome!