How to fill the area under the curve ?

Hi all,

I am currently doing a 3D figure with 3 differents 2D-plots (representing 3 conditions)

1) How can I fill the area under the ploted curves ? It is currently filling the area from the top of the curve up to a random horizontal axis

I previously used the fliplr tool but does not work at the moment here ...

2) How can I invert the y-axis (currently going from 100 to 0, and needs to be from 0 to 100)

Thanks a lot

figure 

y = Data{:,1};
z = Data{:,2};
x = Data{:,3};
fill3(x,y,z,[0.00,0.45,0.74],'LineStyle','none','FaceAlpha',.3)
hold on 
y = Data{:,1};
z = Data{:,4};
x = Data{:,5};
fill3(x,y,z,[0.04,0.49,0.35],'LineStyle','none','FaceAlpha',.3)
hold on 
y = Data{:,1};
z = Data{:,6};
x = Data{:,7};
fill3(x,y,z,[1.00,0.00,0.00],'LineStyle','none','FaceAlpha',.3)

[Matt J]

We don't have your Data variable, so we cannot demonstrate solutions. I suggest attaching it in a .mat file.

[C.PR]

Thank you Matt,

Please find the attached Data File

Answer 1

[Star Strider]

I am not certain what result you want with respect to ‘under the plotted curves’. Adjusting that limit (defined here as ‘min(Data{:,2+2*(k-1)})’) is relatively straightforward if you want to change it.

Try this —

LD = load('Data.mat');
Data = LD.Data

Data = 100×7 table
    VarName1    VarName2    VarName3    VarName4    VarName5    VarName6    VarName7
    ________    ________    ________    ________    ________    ________    ________

        1        67.231        1          73.18        2         112.26        3    
        2        69.409        1         71.076        2         112.61        3    
        3        68.738        1         69.451        2         113.52        3    
        4          70.1        1         69.531        2         109.96        3    
        5         71.74        1         71.117        2         109.97        3    
        6        71.016        1         71.371        2         108.34        3    
        7         71.03        1         70.978        2         107.89        3    
        8        71.213        1         73.032        2         104.09        3    
        9        71.743        1         72.724        2         104.54        3    
       10        73.342        1         72.288        2         103.65        3    
       11        74.851        1         73.168        2         106.35        3    
       12        75.568        1         71.517        2         108.51        3    
       13         77.95        1         72.744        2         103.95        3    
       14        78.961        1         74.973        2         101.72        3    
       15         78.48        1         75.622        2         99.964        3    
       16        76.903        1         74.491        2          102.6        3    

c = 'bgr';

figure
x = Data{:,1};
hold on
for k = 1:3
    % Q = [2+2*(k-1); 3+2*(k-1)]
    % plot3(Data{:,3+2*(k-1)}, x, Data{:,2+2*(k-1)})
    patch([Data{:,3+2*(k-1)}; flip(Data{:,3+2*(k-1)})], [x; flip(x)], [Data{:,2+2*(k-1)}; zeros(size(x))+min(Data{:,2+2*(k-1)})], c(k), 'FaceAlpha',0.5, 'EdgeColor','none')
end
hold off
grid on
view(-30,30)

.

[C.PR]

Thank you very much.

Both answers helped, but showing me the script definitely made my day ! I couldn't find the right syntax for this part "[Data{:,2+2*(k-1)}; zeros(size(x))+min(Data{:,2+2*(k-1)})]"

Thank you very much for your help !

[Star Strider]

As always, my pleasure!

Answer 2

[Image Analyst]

See the FAQ:

https://matlab.fandom.com/wiki/FAQ#How_do_I_shade_the_region_between_two_curves?

Basically you have to define a closed polygon.

[C.PR]

Thank you very much.

It actually gave me the first part of the answer .. however using the patch function in 3D was not an easy task (for me) !