How to force MATLAB function area to hold on in figure - matlab

Question

I'm working on this function which gets axis handler and data, and is supposed to plot it correctly in the axis. The function is called in for loop. It's supposed to draw the multiple data in one figure. My resulted figure is shown below.
There are only two correctly plotted graphs (those with four colors). Others miss areas plotted before the final area (red area is the last plotted area in each graph). But the script is same for every axis. So where can be the mistake? The whole function is written below.
function [] = powerSpectrumSmooth(axis,signal,fs)
N= length(signal);
samplesPer1Hz = N/fs;
delta = int16(3.5*samplesPer1Hz); %last sample of delta frequncies
theta = int16(7.5*samplesPer1Hz); %last sample of theta frequncies
alpha = int16(13*samplesPer1Hz); %last sample of alpha frequncies
beta = int16(30*samplesPer1Hz); %last sample of beta frequncies
x=fft(double(signal));
powerSpectrum = 20*log10(abs(real(x)));
smoothPS=smooth(powerSpectrum,51);
PSmin=min(powerSpectrum(1:beta));
y1=[(smoothPS(1:delta)); zeros(beta-delta,1)+PSmin];
y2=[zeros(delta-1,1)+PSmin; (smoothPS(delta:theta)); zeros(beta-theta,1)+PSmin];
y3=[zeros(theta-1,1)+PSmin; (smoothPS(theta:alpha)); zeros(beta-alpha,1)+PSmin];
y4=[zeros(alpha-1,1)+PSmin; (smoothPS(alpha:beta))];
a1=area(axis,1:beta,y1);
set(a1,'FaceColor','yellow')
hold on
a2=area(axis,1:beta,y2);
set(a2,'FaceColor','blue')
a3=area(axis,1:beta,y3);
set(a3,'FaceColor','green')
a4=area(axis,1:beta,y4);
set(a4,'FaceColor','red')
ADDED
And here is the function which calls the function above.
function [] = drawPowerSpectrum(axesContainer,dataContainer,fs)
size = length(axesContainer);
for l=1:size
powerSpectrumSmooth(axesContainer{l},dataContainer{l},fs)
set(axesContainer{l},'XTickLabel','')
set(axesContainer{l},'YTickLabel','')
uistack(axesContainer{l}, 'top');
end
ADDED 29th July
Here is a script which reproduces the error, so you can run it in your computer. Before running it again you might need to clear variables.
len = 9;
axesContainer = cell(len,1);
x = [0.1,0.4,0.7,0.1,0.4,0.7,0.1,0.4,0.7];
y = [0.1,0.1,0.1,0.4,0.4,0.4,0.7,0.7,0.7];
figure(1)
for i=1:len
axesContainer{i} = axes('Position',[x(i),y(i),0.2,0.2]);
end
dataContainer = cell(len,1);
N = 1500;
for i=1:len
dataContainer{i} = rand(1,N)*100;
end
for l=1:len
y1=[(dataContainer{l}(1:N/4)) zeros(1,3*N/4)];
y2=[zeros(1,N/4) (dataContainer{l}(N/4+1:(2*N/4))) zeros(1,2*N/4)];
y3=[zeros(1,2*N/4) (dataContainer{l}(2*N/4+1:3*N/4)) zeros(1,N/4)];
y4=[zeros(1,3*N/4) (dataContainer{l}(3*N/4+1:N))];
axes=axesContainer{l};
a1=area(axes,1:N,y1);
set(a1,'FaceColor','yellow')
hold on
a2=area(axes,1:N,y2);
set(a2,'FaceColor','blue')
hold on
a3=area(axes,1:N,y3);
set(a3,'FaceColor','green')
hold on
a4=area(axes,1:N,y4);
set(a4,'FaceColor','red')
set(axes,'XTickLabel','')
set(axes,'YTickLabel','')
end
My result of this script is plotted below:
Again only one picture contains all areas.

Answer 1

It looks like that every call to plot(axes,data) deletes whatever was written in axes.
Important note: Do not use a variable name the same as a function. Do not call something sin ,plot or axes!! I changed it to axs.
To solve the problem I just used the classic subplot instead of creating the axes as you did:
len = 9;
axesContainer = cell(len,1);
x = [0.1,0.4,0.7,0.1,0.4,0.7,0.1,0.4,0.7];
y = [0.1,0.1,0.1,0.4,0.4,0.4,0.7,0.7,0.7];
figure(1)
dataContainer = cell(len,1);
N = 1500;
for i=1:len
dataContainer{i} = rand(1,N)*100;
end
for l=1:len
y1=[(dataContainer{l}(1:N/4)) zeros(1,3*N/4)];
y2=[zeros(1,N/4) (dataContainer{l}(N/4+1:(2*N/4))) zeros(1,2*N/4)];
y3=[zeros(1,2*N/4) (dataContainer{l}(2*N/4+1:3*N/4)) zeros(1,N/4)];
y4=[zeros(1,3*N/4) (dataContainer{l}(3*N/4+1:N))];
axs=subplot(3,3,l);
a1=area(axs,1:N,y1);
set(a1,'FaceColor','yellow')
hold on
a2=area(axs,1:N,y2);
set(a2,'FaceColor','blue')
hold on
a3=area(axs,1:N,y3);
set(a3,'FaceColor','green')
hold on
a4=area(axs,1:N,y4);
set(a4,'FaceColor','red')
set(axs,'XTickLabel','')
set(axs,'YTickLabel','')
axis tight % this is to beautify it.
end
As far as I know, you can still save the axs variable in an axescontainer and then modify the properties you want (like location).

Answer 2

I found out how to do what I needed.
len = 8;
axesContainer = cell(len,1);
x = [0.1,0.4,0.7,0.1,0.4,0.7,0.1,0.4];
y = [0.1,0.1,0.1,0.4,0.4,0.4,0.7,0.7];
figure(1)
for i=1:len
axesContainer{i} = axes('Position',[x(i),y(i),0.2,0.2]);
end
dataContainer = cell(len,1);
N = 1500;
for i=1:len
dataContainer{i} = rand(1,N)*100;
end
for l=1:len
y1=[(dataContainer{l}(1:N/4)) zeros(1,3*N/4)];
y2=[zeros(1,N/4) (dataContainer{l}(N/4+1:(2*N/4))) zeros(1,2*N/4)];
y3=[zeros(1,2*N/4) (dataContainer{l}(2*N/4+1:3*N/4)) zeros(1,N/4)];
y4=[zeros(1,3*N/4) (dataContainer{l}(3*N/4+1:N))];
axes=axesContainer{l};
Y=[y1',y2',y3',y4'];
a=area(axes,Y);
set(axes,'XTickLabel','')
set(axes,'YTickLabel','')
end
The area is supposed to work with matrices like this. The tricky part is, that the signal in every next column is not plotted absolutely, but relatively to the data in previous column. That means, if at time 1 the data in first column has value 1 and data in second column has value 4, the second column data is ploted at value 5. Source: http://www.mathworks.com/help/matlab/ref/area.html