[ACCEPTED]-Plotting 4 curves in a single plot, with 3 y-axes-plot

This is a great chance to introduce you 15 to the File Exchange. Though the organization of late 14 has suffered from some very unfortunately 13 interface design choices, it is still a 12 great resource for pre-packaged solutions 11 to common problems. Though many here have 10 given you the gory details of how to achieve 9 this (@prm!), I had a similar need a few 8 years ago and found that addaxis worked very well. (It 7 was a File Exchange pick of the week at one point!) It has inspired later, probably better mods. Here 6 is some example output:

_{(source: mathworks.com)}

I just searched 5 for "plotyy" at File Exchange.

Though understanding 4 what's going on in important, sometimes 3 you just need to get things done, not do 2 them yourself. Matlab Central is great 1 for that.

One possibility you can try is to create 14 3 axes stacked one on top of the other with 13 the 'Color' properties of the top two set to 'none' so 12 that all the plots are visible. You would 11 have to adjust the axes width, position, and 10 x-axis limits so that the 3 y axes are side-by-side 9 instead of on top of one another. You would 8 also want to remove the x-axis tick marks 7 and labels from 2 of the axes since they 6 will lie on top of one another.

Here's a 5 general implementation that computes the 4 proper positions for the axes and offsets 3 for the x-axis limits to keep the plots 2 lined up properly:

%# Some sample data:
x = 0:20;
N = numel(x);
y1 = rand(1,N);
y2 = 5.*rand(1,N)+5;
y3 = 50.*rand(1,N)-50;

%# Some initial computations:
axesPosition = [110 40 200 200];  %# Axes position, in pixels
yWidth = 30;                      %# y axes spacing, in pixels
xLimit = [min(x) max(x)];         %# Range of x values
xOffset = -yWidth*diff(xLimit)/axesPosition(3);

%# Create the figure and axes:
figure('Units','pixels','Position',[200 200 330 260]);
h1 = axes('Units','pixels','Position',axesPosition,...
          'Color','w','XColor','k','YColor','r',...
          'XLim',xLimit,'YLim',[0 1],'NextPlot','add');
h2 = axes('Units','pixels','Position',axesPosition+yWidth.*[-1 0 1 0],...
          'Color','none','XColor','k','YColor','m',...
          'XLim',xLimit+[xOffset 0],'YLim',[0 10],...
          'XTick',[],'XTickLabel',[],'NextPlot','add');
h3 = axes('Units','pixels','Position',axesPosition+yWidth.*[-2 0 2 0],...
          'Color','none','XColor','k','YColor','b',...
          'XLim',xLimit+[2*xOffset 0],'YLim',[-50 50],...
          'XTick',[],'XTickLabel',[],'NextPlot','add');
xlabel(h1,'time');
ylabel(h3,'values');

%# Plot the data:
plot(h1,x,y1,'r');
plot(h2,x,y2,'m');
plot(h3,x,y3,'b');

and here's the resulting 1 figure:

I know of plotyy that allows you to have two y-axes, but 5 no "plotyyy"!

Perhaps you can normalize 4 the y values to have the same scale (min/max 3 normalization, zscore standardization, etc..), then 2 you can just easily plot them using normal 1 plot, hold sequence.

Here's an example:

%# random data
x=1:20;
y = [randn(20,1)*1 + 0 , randn(20,1)*5 + 10 , randn(20,1)*0.3 + 50];

%# plotyy
plotyy(x,y(:,1), x,y(:,3))

%# orginial
figure
subplot(221), plot(x,y(:,1), x,y(:,2), x,y(:,3))
title('original'), legend({'y1' 'y2' 'y3'})

%# normalize: (y-min)/(max-min) ==> [0,1]
yy = bsxfun(@times, bsxfun(@minus,y,min(y)), 1./range(y));
subplot(222), plot(x,yy(:,1), x,yy(:,2), x,yy(:,3))
title('minmax')

%# standarize: (y - mean) / std ==> N(0,1)
yy = zscore(y);
subplot(223), plot(x,yy(:,1), x,yy(:,2), x,yy(:,3))
title('zscore')

%# softmax normalization with logistic sigmoid ==> [0,1]
yy = 1 ./ ( 1 + exp( -zscore(y) ) );
subplot(224), plot(x,yy(:,1), x,yy(:,2), x,yy(:,3))
title('softmax')

Multi-scale plots are rare to find beyond 6 two axes... Luckily in Matlab it is possible, but 5 you have to fully overlap axes and play 4 with tickmarks so as not to hide info.

Below 3 is a nice working sample. I hope this is 2 what you are looking for (although colors 1 could be much nicer)!

close all
clear all 

display('Generating data');

x = 0:10;
y1 = rand(1,11);
y2 = 10.*rand(1,11);
y3 = 100.*rand(1,11);
y4 = 100.*rand(1,11);

display('Plotting');

figure;
ax1 = gca;
get(ax1,'Position')
set(ax1,'XColor','k',...
    'YColor','b',...
    'YLim',[0,1],...
    'YTick',[0, 0.2, 0.4, 0.6, 0.8, 1.0]);
line(x, y1, 'Color', 'b', 'LineStyle', '-', 'Marker', '.', 'Parent', ax1)

ax2 = axes('Position',get(ax1,'Position'),...
           'XAxisLocation','bottom',...
           'YAxisLocation','left',...
           'Color','none',...
           'XColor','k',...
           'YColor','r',...
           'YLim',[0,10],...
           'YTick',[1, 3, 5, 7, 9],...
           'XTick',[],'XTickLabel',[]);
line(x, y2, 'Color', 'r', 'LineStyle', '-', 'Marker', '.', 'Parent', ax2)

ax3 = axes('Position',get(ax1,'Position'),...
           'XAxisLocation','bottom',...
           'YAxisLocation','right',...
           'Color','none',...
           'XColor','k',...
           'YColor','g',...
           'YLim',[0,100],...
           'YTick',[0, 20, 40, 60, 80, 100],...
           'XTick',[],'XTickLabel',[]);
line(x, y3, 'Color', 'g', 'LineStyle', '-', 'Marker', '.', 'Parent', ax3)

ax4 = axes('Position',get(ax1,'Position'),...
           'XAxisLocation','bottom',...
           'YAxisLocation','right',...
           'Color','none',...
           'XColor','k',...
           'YColor','c',...
           'YLim',[0,100],...
           'YTick',[10, 30, 50, 70, 90],...
           'XTick',[],'XTickLabel',[]);
line(x, y4, 'Color', 'c', 'LineStyle', '-', 'Marker', '.', 'Parent', ax4)

_{(source: pablorodriguez.info)}

PLOTYY allows two different y-axes. Or you might 8 look into LayerPlot from the File Exchange. I guess 7 I should ask if you've considered using 6 HOLD or just rescaling the data and using regular 5 old plot?

OLD, not what the OP was looking for: SUBPLOT allows 4 you to break a figure window into multiple 3 axes. Then if you want to have only one 2 x-axis showing, or some other customization, you 1 can manipulate each axis independently.

In your case there are 3 extra y axis (4 3 in total) and the best code that could be 2 used to achieve what you want and deal with 1 other cases is illustrated above:

clear
clc

x = linspace(0,1,10);
N = numel(x);
y = rand(1,N);
y_extra_1 = 5.*rand(1,N)+5;
y_extra_2 = 50.*rand(1,N)+20;
Y = [y;y_extra_1;y_extra_2];

xLimit = [min(x) max(x)];
xWidth = xLimit(2)-xLimit(1);
numberOfExtraPlots = 2;
a = 0.05;
N_ = numberOfExtraPlots+1;

for i=1:N_
    L=1-(numberOfExtraPlots*a)-0.2;
    axesPosition = [(0.1+(numberOfExtraPlots*a)) 0.1 L 0.8];
    if(i==1)
        color = [rand(1),rand(1),rand(1)];
        figure('Units','pixels','Position',[200 200 1200 600])
        axes('Units','normalized','Position',axesPosition,...
            'Color','w','XColor','k','YColor',color,...
            'XLim',xLimit,'YLim',[min(Y(i,:)) max(Y(i,:))],...
            'NextPlot','add');
        plot(x,Y(i,:),'Color',color);
        xlabel('Time (s)');

        ylab = strcat('Values of dataset 0',num2str(i));
        ylabel(ylab)

        numberOfExtraPlots = numberOfExtraPlots - 1;
    else
        color = [rand(1),rand(1),rand(1)];
        axes('Units','normalized','Position',axesPosition,...
            'Color','none','XColor','k','YColor',color,...
            'XLim',xLimit,'YLim',[min(Y(i,:)) max(Y(i,:))],...
            'XTick',[],'XTickLabel',[],'NextPlot','add');
        V = (xWidth*a*(i-1))/L;
        b=xLimit+[V 0];
        x_=linspace(b(1),b(2),10);
        plot(x_,Y(i,:),'Color',color);
        ylab = strcat('Values of dataset 0',num2str(i));
        ylabel(ylab)

        numberOfExtraPlots = numberOfExtraPlots - 1;
    end
end

The code above will produce something like this: