MATLAB: Filling the area between multiple lines

Question

A book I'm reading contains the following diagram.

I'm looking to replicate as closely as possible the following diagram in MATLAB. I managed to recreate the lines, but am having trouble filling the colours in.

possible_colours = {'r','g','b','c','m','y','w','k','r'};

H = [0.01:0.01:0.99];

colour_counter = 0;

for ii = -0.8:0.2:0.8
    colour_counter = colour_counter + 1;
    colour_now = possible_colours{colour_counter};
    ORSS = ones(1,size(H,2))*ii;
    F = (H .* (1-ORSS)) ./ ((1-2.*H) .* ORSS + 1);
    hold on    
    plot(F,H)
    fill(F,H,colour_now);    
end

With fill(F,H,colour_now) taken out the code perfectly recreates the required lines. However, the fill isn't correct.

This heavily upvoted answer by @Doresoom seems relevant, but it's a bit different because in that example the x-values are held constant, while in my case it's the y-values that are held constant. Also, in that case there is only a pair lines, whereas I have lots of them.

Answer 1

I think this is a solution:

%possible_colours = {'r','g','b','c','m','y','w','k','r'};
possible_colours = {'r','g','b','c','r','k','w','y','m'};

H = [0.01:0.01:0.99];

figure; hold on
fill([0 1 1],[0 0 1],colorlowerhalf)
fill([0 1 0],[0 1 1],colorupperhalf)

colour_counter = 0;

for ii = -0.8:0.2:0
    colour_counter = colour_counter + 1;
    colour_now = possible_colours{colour_counter};
    ORSS = ones(1,size(H,2))*ii;
    F = (H .* (1-ORSS)) ./ ((1-2.*H) .* ORSS + 1);
    hold on    
    plot(F,H)
    fill(F,H,colour_now);    
end

for ii = 0.8:-0.2:0
    colour_counter = colour_counter + 1;
    colour_now = possible_colours{colour_counter};
    ORSS = ones(1,size(H,2))*ii;
    F = (H .* (1-ORSS)) ./ ((1-2.*H) .* ORSS + 1);
    hold on    
    plot(F,H)
    fill(F,H,colour_now);    
end

It permits to avoid the overlap of the filled areas.

But there still is some problem with the definition of the areas to fill.

For that you need to redefine H:

H = [0:0.01:1];