How to fill the stair plots with some color.

Hello,

Below are plots (subplot) and having Figure 1 I wanted to fill these stairs (inside) same as figure 2 . I really appreciate your help in this regard.

Figure: 1

Figure 2

[Renato SL]

I wouldn't call it as to fill the stair plots with some color.

I think the Figure 1 was made using the plot function, while Figure 2 was made using the stem function. The "color" you see is the stems of the plotted values.

Documentation of the stem function here.

[Adam Danz]

The image in "figure 2" is not really a fill. As Renato SL pointed out, it's a bunch of stem plot lines which requires a lot of data points to appear as "filled". A patch is a better approach.

Answer 1

[Adam Danz]

This solution reproduces the (x,y) coordinates for the staircase and then uses fill() to fill in the area under the stairs.

% Create demo plot
X = linspace(0,4*pi,40);
Y = sin(X);
figure
sh = stairs(Y); 
hold on

% Get the (y,x) coordinates from the original inputs or from  
% the xdata and ydata properties of the stair object which will
% always be row vectors.  

bottom = -1.5; %identify bottom; or use min(sh.YData)

x = [sh.XData(1),repelem(sh.XData(2:end),2)];
y = [repelem(sh.YData(1:end-1),2),sh.YData(end)];
% plot(x,y,'y:') %should match stair plot

% Fill area
fill([x,fliplr(x)],[y,bottom*ones(size(y))], 'g')

[shane watson]

figure(1)
subplot(2,1,1)
1=[6.5 6.5 6.5 6.5 6.5 6.5 6.5 9.4 9.4 9.4 9.4 13.4 13.4 13.4 13.4 13.4 13.4 9.4 9.4 6.5 6.5 6.5 6.5 6.5];
i=1:24;
stairs(i,1,'g-','LineWidth',1);
grid minor
subplot(2,1,2)
2=[6.5 6.5 6.5 6.5 6.5 6.5 6.5 13.2 13.2 13.2 13.2 9.4 9.4 9.4 9.4 9.4 9.4 13.2 13.2 6.5 6.5 6.5 6.5 6.5];
stairs(i,2,'b-','LineWidth',1);

@Adam, I'm using this code for figure 1. However, can you show me the extact way to fill inside of the green and blue line in figure. Thanks

[Adam Danz]

I can show you how to adapt my answer to your data.

1. The code in your comment above has two errors. The vector of inputs is assigned to variables named '1' and '2' and this is not allowed in matlab (you would get an error message). So rename those variables. For now I'll call them 'data1' and 'data2'.
2. After you plot those data in the stairs() plot, save the output which is a handle to the stairs object (just like in my answer). sh = stairs(. . .)
3. Be sure to "hold on" so the axis isn't cleared when you add more stuff to it.
4. Decide what "bottom" value to use (see my answer). The bottom value will be the bottom of the patch you're adding.
5. The rest is as simple as copying the rest of my code.

If you get stuck, share your updated code and explain where you're stuck.

[shane watson]

Excellent @Adam!! Thanks for helping.

[Adam Danz]

Nice!

Glad I could help.

[shane watson]

Hello @Adam Danz,

I have similar thing to ask, that is If I have figure which is ploted with plot command not stairs then how to fill color because this isn't working with plot command. Thanks in advance.

[Adam Danz]

If your variables are x and y and both are row vectors, try

bottom = -1.5; %identify bottom; or use min(y)
% Fill area
plot(x,y)
hold on
fill([x,fliplr(x)],[y,bottom*ones(size(y))], 'g')

[shane watson]

Here is my code I have used your suggestion but it didnt work as it should be can you look into it. I'm trying to plot with filled colors.

time=1:24;
EP=[13.2 13.2 9.4 9.4 9.4 9 9 9 9 7 9 9 0 0 0 0 0 0 0 9 9 9 9 7];
New1=plot(time,EP,'b-','LineWidth',2);
hold on
New2=plot(time,x,'G+-','LineWidth',1.8) %x , y, and z are arrays of  24 values
hold on
New3=plot(time,y,'G+-','LineWidth',1.8);
hold on
New4=plot(time,z,'G+-','LineWidth',1.8);
hold on
set(gca,'color','w','FontSize',7,'FontWeight','Bold','XTickLabelRotation',45,'XTick',1:24, 'XTickLabel',{'1' '1' '2' '3' '4' '5' '6' '7' '8' '9' '10' '11' '12' '1' '2' '3' '4' '5' '6' '7' '8' '9' '10' '11'});

[Adam Danz]

I just tested my suggestion with your code and it works perfectly.

x = time
y = EP
% See rest of my suggestion

If it still doesn't work you'll need to explain what's not working and I suggest doing that in a new question rather than extending this thread since the topic slightly differs (you could provide the link to the new question here).

[shane watson]

Thanks once again, it worked. However, I also posted related question on the following link, kindly check it https://se.mathworks.com/matlabcentral/answers/494956-adding-transparency-when-filling-color-in-plots