how to fill between 2 graphs

Hi eveybody

I could not fill the gap betwween 2 curves. it is shown in below figure.

can anyone help me?

thanks

The code I used is:

plot(KI1,KP1);
xlabel('K_I');
ylabel('K_P');
grid on
hold on

x2=zeros(1,150)
y=linspace(-20,40,numel(x2))
plot(x2,y,'linewidth',2)

[darova]

Did you try area? What about intersection fo curves?

[halil hasan]

I tried, but may be wrong parameter selection I couldnt succeded.

[darova]

Maybe i can correct your code? Allow me to help you

[halil hasan]

thanks drova

I have given the code above.

[darova]

I have an error here

Do you know why?

[halil hasan]

KI1 and KP1 are vectors. they can have any value.

Answer 1

[Les Beckham]

What do you mean by "fill the gap"? Do you want to connect the start and end points so that this becomes a closed curve? If so, this should do it:

plot([KI1(:); KI1(1)], [KP1(:); KP1(1)]);
xlabel('K_I');
ylabel('K_P');
grid on

[halil hasan]

Thanks alot for replay Beckham

This is 2 different curve. I wanna fill intersection of them(closed area) with a color.

[Les Beckham]

In that case, try something like this (I've made up some data that is somewhat similar to your plot, though not as smooth).

KI1 = [0 -190 -100 0 90 80];
KP1 = [40 5 -18 -16 -5 -2];
fill([KI1(:); KI1(1)], [KP1(:); KP1(1)], 'b', 'EdgeColor', 'None') % Fill the shape with blue
hold on
plot([KI1(:); KI1(1)], [KP1(:); KP1(1)], 'k', 'LineWidth', 2) % Outline the edges in black
xlabel('KI1')
ylabel('KP1')

If this doesn't get you to what you want, it would help if you share the data for KI1 and KP1.

[halil hasan]

Thanks alot Beckham

but I want to fill KI1<0 part, not all of them

[halil hasan]

how to fill just left of KI=0 line in your figure?

[Les Beckham]

Maybe this will do what you want:

KI1 = [0 -190 -100 0 90 80];
KP1 = [40 5 -18 -16 -5 -2];
idx = find(KI1 <= 0); % find indices of non-positive KI1 values
fill([KI1(idx)  KI1(find(idx,1))], [KP1(idx)  KP1(find(idx,1))], 'b', 'EdgeColor', 'None')
hold on
plot([KI1(:); KI1(1)], [KP1(:); KP1(1)], 'k', 'LineWidth', 2)
xlabel('KI1')
ylabel('KP1')

[halil hasan]

Thanks alot for your kind replies, Beckham

[Les Beckham]

You are welcome. Glad I could help.

Answer 2

[darova]

Here is my shot

y = 0:0.1:pi;
x1 = -sin(y);
x2 = y*0-0.3;

[xc,yc] = polyxpoly(x1,y,x2,y);
xx = [xc(1) x1(x1<x2) xc(end)];
yy = [yc(1) y(x1<x2) yc(end)];

plot(x1,y,x2,y)
patch(xx,yy,'r')
line(xc,yc,'marker','o')

success?

[halil hasan]

Thanks alot for your kind reply, Darova