Plot a data series beneath another one - matlab

When you plot things in Matlab, the most recently plotted data series is placed on top of whatever's already there. For example:
figure; hold on
plot(sin(linspace(0,pi)),'linewidth',4,'color',[0 0 1])
plot(cos(linspace(0,pi)),'linewidth',4,'color',[1 0 0])
Here, the red line is shown on top of the blue line (where they intersect). Is there any way to set "how deep" a line is drawn, so that you can plot things beneath what's already there?


Use the uistack command. For example:
h1 = plot(1:10, 'b');
hold on;
h2 = plot(1:10, 'r');
will plot two lines with the red line plotted on top of the blue line. If you then do:
uistack(h1);
the blue line will be brought to the front.


You can also accomplish this by setting the order of the children vector of the current axes. If you do the following:
figure; hold on
h1 = plot(sin(linspace(0,pi)),'linewidth',4,'color',[0 0 1]);
h2 = plot(cos(linspace(0,pi)),'linewidth',4,'color',[1 0 0]);
h = get(gca, 'Children');
you will see that h is a vector that contains h1 and h2. The graphical stacking order is represented by the order of the handles in h. In this example, to reverse the stacking order you could do:
h = flipud(h);
set(gca, 'Children', h);

Related

Remove border around axes but keep the grid and ticklabels [duplicate]

Is there a way to remove only the axis lines in the Matlab figure, without affecting ticks and tick labels.
I know that box toggles the upper and right axes lines and ticks and that works perfectly for me.
But my problem is that I want eliminate the bottom and left lines (only lines!) but keeping the ticks and tick labels.
Any tricks?

Yair Altman's Undocumented Matlab demonstrates a cleaner way to do this using the undocumented axes rulers:
plot(x,y);
ax1 = gca;
yruler = ax1.YRuler;
yruler.Axle.Visible = 'off';
xruler = ax1.XRuler;
xruler.Axle.Visible = 'off'; %// note you can do different formatting too such as xruler.Axle.LineWidth = 1.5;
A nice feature of this approach is that you can separately format the x and y axis lines.

Solution for Matlab versions prior to R2014b
You can introduce a new white bounding box and put it on top.
// example data
x = linspace(-4,4,100);
y = 16 - x.^2;
plot(x,y); hold on
ax1 = gca;
set(ax1,'box','off') %// here you can basically decide whether you like ticks on
%// top and on the right side or not
%// new white bounding box on top
ax2 = axes('Position', get(ax1, 'Position'),'Color','none');
set(ax2,'XTick',[],'YTick',[],'XColor','w','YColor','w','box','on','layer','top')
%// you can plot more afterwards and it doesn't effect the white box.
plot(ax1,x,-y); hold on
ylim(ax1,[-30,30])
Important is to deactivate the ticks of the second axes, to keep the ticks of the f rist one.
In Luis Mendo's solution, the plotted lines are fixed and stay at their initial position if you change the axes properties afterwards. That won't happen here, they get adjusted to the new limits. Use the correct handle for every command and there won't be much problems.
Dan's solution is easier, but does not apply for Matlab versions before R2014b.

There is another undocumented way (applicable to MATLAB R2014b and later versions) of removing the lines by changing the 'LineStyle' of rulers to 'none'.
Example:
figure;
plot(1:4,'o-'); %Plotting some data
pause(0.1); %Just to make sure that the plot is made before the next step
hAxes = gca; %Axis handle
%Changing 'LineStyle' to 'none'
hAxes.XRuler.Axle.LineStyle = 'none';
hAxes.YRuler.Axle.LineStyle = 'none';
%Default 'LineStyle': 'solid', Other possibilities: 'dashed', 'dotted', 'dashdot'
This is different from Dan's answer which uses the 'visible' property of rulers.

You could "erase" the axis lines by plotting a white line over them:
plot(1:4,1:4) %// example plot
box off %// remove outer border
hold on
a = axis; %// get axis size
plot([a(1) a(2)],[a(3) a(3)],'w'); %// plot white line over x axis
plot([a(1) a(1)],[a(3) a(4)],'w'); %// plot white line over y axis
Result:
As noted by #SardarUsama, in recent Matlab versions you may need to adjust the line width to cover the axes:
plot(1:4,1:4) %// example plot
box off %// remove outer border
hold on
a = axis; %// get axis size
plot([a(1) a(2)],[a(3) a(3)],'w', 'linewidth', 1.5); %// plot white line over x axis.
%// Set width manually
plot([a(1) a(1)],[a(3) a(4)],'w', 'linewidth', 1.5);

Add custom legend without any relation to the graph

I wish to insert a legend that is not related to the graph whatsoever:
figure;
hold on;
plot(0,0,'or');
plot(0,0,'ob');
plot(0,0,'ok');
leg = legend('red','blue','black');
Now I wish to add it to another figure:
figure;
t=linspace(0,10,100);
plot(t,sin(t));
%% ADD THE LEGEND OF PLOT ABOVE

This is how I have solved this problem in the past:
figure
t=linspace(0,10,100);
plot(t,sin(t));
hold on;
h = zeros(3, 1);
h(1) = plot(NaN,NaN,'or');
h(2) = plot(NaN,NaN,'ob');
h(3) = plot(NaN,NaN,'ok');
legend(h, 'red','blue','black');
This will plot the additional points, but because the coordinates are at NaN they will not be visible on the plot itself:
EDIT 26/10/2016: My original answer results in greyed out legend entries in 2016b. The updated code above works, but the answer below is only relevant pre-2016b:
figure
t=linspace(0,10,100);
plot(t,sin(t));
hold on;
h = zeros(3, 1);
h(1) = plot(0,0,'or', 'visible', 'off');
h(2) = plot(0,0,'ob', 'visible', 'off');
h(3) = plot(0,0,'ok', 'visible', 'off');
legend(h, 'red','blue','black');
This will plot the additional points, but they will not be visible on the plot itself.
You can also use copyobj to copy graphics elements from one figure to another if you have a lot of elements, then use set(x, 'visible', 'off') to hide them before showing the legend, but it depends on what your final application is.

Your question is a little unclear. However, the first thing I thought of when reading it was the text function in Matlab.
You can use the text function to add text to a Matlab figure. It's use is
>> text(x, y, str);
where x and y are the coordinates in the figure where you want to add the text str. You can use the Color option of text for colours and TeX to draw lines or even _. I've gotten very creative with plots using text.
Here's a quick and dirty example of emulating a legend with text
x = 0:pi/20:2*pi;
y = sin(x);
plot(x,y)
axis tight
legend('sin(x)');
text(5.7, 0.75, 'sin(x)');
text(5.1, 0.78, '_____', 'Color', 'blue');
which produces
For this specific case you could use the specific command (noted by #Hoki in the comments).
ht = text(5, 0.5, {'{\color{red} o } Red', '{\color{blue} o } Blue', '{\color{black} o } Black'}, 'EdgeColor', 'k');
to produce
by retrieving the handle to the text object it becomes trivial to copy it to a new figure, copyobj(ht, newfig). [1]

How to plot the overlapping area of figures in Matlab?

I want to plot the overlapping area of 2 rectangles in a color. I know I can plot the rectangles by using the rectangle command. With rectint I can find out whether they overlap or not.
Is there a specific command for this or does anyone know how I can do this? As you have noticed, I do not have much experience with Matlab.
Code:
A = [0 0 3 3];
B = [2 2 2 2];
hold on;
rectangle('Position',A) %plot rectangle A
rectangle('Position',B) %plot rectangle B
if (rectint(A,B) > 0)
%plot overlapping
end
hold off;
Image:

Assuming the rectangles overlap, the part for the plotting could be done like this:
if (A(1)<=B(1))
intersection(1)=B(1);
intersection(3)=A(1)+A(3)-B(1);
else
intersection(1)=A(1);
intersection(3)=B(1)+B(3)-A(1);
end
if (A(2)<=B(2))
intersection(2)=B(2);
intersection(4)=A(2)+A(4)-B(2);
else
intersection(2)=A(2);
intersection(4)=B(2)+B(4)-A(2);
end
intersectionPlot=rectangle('Position', intersection);
set(intersectionPlot, 'FaceColor', 'r'); % r stands for red, you can choose any other color

So you only want to plot the little rectangle in the middle?
I don't think that there is a builtin function for that, and this is probably the way to go:
Determine the coordinates of the intersection (as long as it are just rectangles this should not be too hard)
Plot the result

Matlab Ploting with different color for iso-surface

I was trying use the code shown below to plot in such a way that each iso-surface will be different in color and there will be a color bar at the right. I made a ss(k) color matrix for different colors. Number of iso-surfaces is 10 but I have only 8 colors. That's why I wrote ss(9)='r' and ss(10)='r'.
I need a solution to plot the iso-surface with different color and bar at the right side.
ss=['y','m','c','r','g','b','w','k','r','r']
k=1;
for i=.1:.1:1
p=patch(isosurface(x,y,z,v,i));
isonormals(x,y,z,v,p)
hold on;
set(p,'FaceColor',ss(k),'EdgeColor','none');
daspect([1,1,1])
view(3); axis tight
camlight
lighting gouraud
k=k+1;
end

Another possibility is to draw the patches with direct color-mapping (by setting the property 'CDataMapping'='direct'), while assigning the 'CData' of each patch to an index in the colormap of your choice. This is in fact recommended for maximum graphics performance.
Consider the following example:
%# volumetric data, and iso-levels we want to visualize
[x,y,z,v] = flow(25);
isovalues = linspace(-2.5,1.5,6);
num = numel(isovalues);
%# plot isosurfaces at each level, using direct color mapping
figure('Renderer','opengl')
p = zeros(num,1);
for i=1:num
p(i) = patch( isosurface(x,y,z,v,isovalues(i)) );
isonormals(x,y,z,v,p(i))
set(p(i), 'CData',i);
end
set(p, 'CDataMapping','direct', 'FaceColor','flat', 'EdgeColor','none')
%# define the colormap
clr = hsv(num);
colormap(clr)
%# legend of the isolevels
%#legend(p, num2str(isovalues(:)), ...
%# 'Location','North', 'Orientation','horizontal')
%# fix the colorbar to show iso-levels and their corresponding color
caxis([0 num])
colorbar('YTick',(1:num)-0.5, 'YTickLabel',num2str(isovalues(:)))
%# tweak the plot and view
box on; grid on; axis tight; daspect([1 1 1])
view(3); camproj perspective
camlight; lighting gouraud; alpha(0.75);
rotate3d on
I also included (commented) code to display the legend, but I found it to be redundant, and a colorbar looks nicer.

Matlab usually plots different iso-surfaces in different colors automatically, so you don't need to care about that. What kind of bar do you need? A colorbar or a legend? Either way, it is just to use the colorbar or legend function..
%Create some nice data
[x y z] = meshgrid(1:5,1:5,1:5);
v = ones(5,5,5);
for i=1:5
v(:,:,i)=i;
end
v(1:5,3:5,2)=1
v(1:5,4:5,3)=2
%Plot data
for i=1:5
isosurface(x,y,z,v,i)
end
%Add legend and/or colorbar
legend('one','Two','Three','Four')
colorbar

Since the color bar encodes value->color, it is impossible to do what you ask for, unless there is no intersection in z-values between all pairs of surfaces. So the solution below assumes this is the case. If this is not the case, you can still achieve it by adding a constant value to each surface, so to separate the surfaces along the z axis, and eliminate any intersection.
The solution is based on constructing a colormap matrix of piecewise constant values, distributed similarly to the z values of your surfaces. So for example, if you have 3 surfaces, the first has z values between 1 and 10, the 2nd between 11 and 30, and the 3rd between 31 and 60, you should do something like this (I plot in 2D for simplicity)
r = [1 0 0];
g = [0 1 0];
b = [0 0 1];
cmap = [r(ones(10,1),:); g(ones(20,1),:); b(ones(30,1),:)];
z1 = 1:10;
z2 = 11:30;
z3 = 31:60;
figure; hold on
plot(z1,'color',r)
plot(z2,'color',g)
plot(z3,'color',b)
colorbar
colormap(cmap)
More complex colormaps (i.e, more colors) can be constructed with different mixtures of red, green, and blue (http://www.mathworks.com/help/techdoc/ref/colorspec.html)

Minor grid with solid lines & grey-color

I'm using the following to display the minor grid in my plot:
grid(gca,'minor')
set(gca,'MinorGridLineStyle','-')
but I'd like to change the color of the grid lines to a nice greyscale. I can't find any option 'grid color' in matlab... Do you know any or any workaround?
I found this: http://www.mathworks.com/matlabcentral/fileexchange/9815-gridcolor but as I read of the comments, it doesn't work very well and further it only changes gridcolor, not the color of the minor grid...
Thanks!
EDIT:
Problem with semilogx as posting here now:
x = [1e-9 1e-8 1e-7 1e-6 1e-5 1e-4 1e-3 1e-2]';
y1 = linspace(20, 90, 8);
y2 = y1.^2;
y3 = y1./y2+5;
% plotte: http://www.mathworks.com/help/techdoc/ref/linespec.html
myfig = figure('Position', [500 500 445 356]); %[left, bottom, width, height]:
p1 = semilogx(x,y1,'x--r',x,y2,'*-b');
ax1 = gca;
set(ax1, 'Position',[0.13 0.18 0.75 0.75]);
xlim([0 max(x)]);
ylim([0 max([max(y1) max(y2)])]);
col=.85*[1 1 1];
%# create a second transparent axis, same position/extents, same ticks and labels
ax2 = axes('Position',get(ax1,'Position'), ...
'Color','none', 'Box','on', ...
'XTickLabel',get(ax1,'XTickLabel'), 'YTickLabel',get(ax1,'YTickLabel'), ...
'XTick',get(ax1,'XTick'), 'YTick',get(ax1,'YTick'), ...
'XLim',get(ax1,'XLim'), 'YLim',get(ax1,'YLim'),...
'XScale', 'log');
%# show grid-lines of first axis, give them desired color, but hide text labels
set(ax1, 'XColor',col, 'YColor',col, ...
'XMinorGrid','on', 'YMinorGrid','on', ...
'MinorGridLineStyle','-', ...
'XTickLabel',[], 'YTickLabel',[],'XScale', 'log');
%# link the two axes to share the same limits on pan/zoom
linkaxes([ax1 ax2],'xy');
Displaying like this:
EDIT2: A problem occurs when adding a second y-axes as in the following picture, look at the ticks of the right y-axes:
this will be discussed here to have a better overview!
Matlab: Problem with ticks when setting minor grid style and two y-axis

Set the 'XColor','YColor' axes properties. Note that these properties determine the color of the axis lines, tick marks, tick mark labels, and the axis grid lines, so AFAIK you can't assign those different colors than that of the entire axis..
Example:
plot(rand(10,1))
set(gca, 'XMinorGrid','on', 'YMinorGrid','on', 'XColor','r', 'YColor','g')
EDIT1:
You can always create a second transparent axis with the desired grid colors, but with no ticks or labels, stacked on top of the current axis. Here is an example:
%# create plot as usual
plot(rand(10,1))
hAx1 = gca;
%# create a second axis, same position/extents, no tick or labels, colored grid-lines
hAx2 = axes('Position',get(hAx1,'Position'), ...
'Color','none', 'TickLength',[1e-100 1e-100], ...
'XMinorGrid','on', 'YMinorGrid','on', ...
'Box','off', 'XColor','g', 'YColor','r', ...
'XTickLabel',[], 'YTickLabel',[], ...
'XTick',get(hAx1,'XTick'), 'YTick',get(hAx1,'YTick'), ...
'XLim',get(hAx1,'XLim'), 'YLim',get(hAx1,'YLim'));
%# position it on top
%#uistack(hAx2,'top')
%# redraw the enclosing box in the original axis colors
x = get(hAx1,'XLim');
y = get(hAx1,'YLim');
line([x([1 2]) nan x([2 1])],[y([1 1]) nan y([2 2])],'Color',get(hAx1,'XColor'))
line([x([1 1]) nan x([2 2])],[y([1 2]) nan y([2 1])],'Color',get(hAx1,'YColor'))
The only problem is that the grid lines are drawn on top of your plot, which might get in the way if the grid-lines are thick :)
EDIT2:
Seems like #yoda had a similar idea to the above. Here is a slightly improved version inspired by his solution:
%# create plot as usual
plot(11:20, rand(10,1)*5)
hAx1 = gca; %# get a handle to first axis
%# create a second transparent axis, same position/extents, same ticks and labels
hAx2 = axes('Position',get(hAx1,'Position'), ...
'Color','none', 'Box','on', ...
'XTickLabel',get(hAx1,'XTickLabel'), 'YTickLabel',get(hAx1,'YTickLabel'), ...
'XTick',get(hAx1,'XTick'), 'YTick',get(hAx1,'YTick'), ...
'XLim',get(hAx1,'XLim'), 'YLim',get(hAx1,'YLim'));
%# show grid-lines of first axis, give them desired color, but hide text labels
set(hAx1, 'XColor','g', 'YColor','r', ...
'XMinorGrid','on', 'YMinorGrid','on', ...
'XTickLabel',[], 'YTickLabel',[]);
%# link the two axes to share the same limits on pan/zoom
linkaxes([hAx1 hAx2],'xy');
%# lets create a legend, and some titles
legend(hAx1, 'text')
title('title'), xlabel('x'), ylabel('y')
EDIT3 (take 2):
Here is the same example but with a log-scale x-axis. Note how instead of creating a second axis and manually setting its properties to match the first, I simply copyobj the axis, and delete its children.
%# create a plot as usual (x-axis is in the log-scale)
semilogx(logspace(0,5,100), cumsum(rand(100,1)-0.5))
xlabel('x'), ylabel('y'), title('text')
legend('plot')
%# capture handle to current figure and axis
hFig = gcf;
hAx1 = gca;
%# create a second transparent axis, as a copy of the first
hAx2 = copyobj(hAx1,hFig);
delete( get(hAx2,'Children') )
set(hAx2, 'Color','none', 'Box','on', ...
'XGrid','off', 'YGrid','off')
%# show grid-lines of first axis, style them as desired,
%# but hide its tick marks and axis labels
set(hAx1, 'XColor',[0.9 0.9 0.9], 'YColor',[0.9 0.9 0.9], ...
'XMinorGrid','on', 'YMinorGrid','on', 'MinorGridLineStyle','-', ...
'XTickLabel',[], 'YTickLabel',[]);
xlabel(hAx1, ''), ylabel(hAx1, ''), title(hAx1, '')
%# link the two axes to share the same limits on pan/zoom
linkaxes([hAx1 hAx2], 'xy');
%# Note that `gca==hAx1` from this point on...
%# If you want to change the axis labels, explicitly use hAx2 as parameter.
You should get the correct plot in your example with this code. However I think the x variable values you choose might be too close in the current figure size to show all the vertical lines (simply maximize the figure to see what I mean)...
To get a better idea of what each axis contains, here is a divided view where the plot on the left contains only the graphics rendered by hAx1, while the plot on right contains only the hAx2 components. Those two views are basically overlayed on top of each other in the final figure shown before.

Unfortunately, while the trick of over- or under-laying a second, gridded axes mostly works, Matlab does not render it properly when you save to a PDF file. This is because Matlab does not support transparency in PDFs.
One workaround is to simply use line to draw in the grid lines one by one:
for dir='XY';
ticks = get(gca, [dir 'Tick']);
lim = get(gca, [dir 'lim']);
for ii=1:length(ticks)
coord = ticks(ii);
for jj=1:9,
if jj==1 % major grid properties
color = [1 1 1]*0.9;
weight = 2;
else % minor grid properties
color = [1 1 1]*0.9;
weight = 1;
end
if jj*coord > lim(2)
continue
end
if dir=='X'
L = line((jj*coord)*[1 1], get(gca, 'ylim'), ...
'color', color, 'linewidth', weight);
else
L = line(get(gca, 'xlim'), (jj*coord)*[1 1], ...
'color', color, 'linewidth', weight);
end
uistack(L, 'bottom');
end
end
end
One downside of this approach is that it overwrites the tick marks and plot boundary box. A solution to this is to combine this approach with the trick of under-laying a second axes. Draw the fake grid on the underlying axes. This IS rendered properly in PDF:

While Amro is right that the minor grid's color is the same as that of the axis labels, you can always turn off the axis labels and overlay a second axes with transparent filling and set the labels on that in a different color. Here's a small example showing how:
plot(rand(10,1))
xTicks=get(gca,'xTick');
yTicks=get(gca,'ytick');
set(gca, 'XMinorGrid','on', 'YMinorGrid','on',...
'XColor','r', 'YColor','g','xticklabel',[],'yticklabel',[],...
'box','off')
h2=axes;
set(h2,'color','none','xtick',linspace(0,1,numel(xTicks)),'xticklabel',xTicks,...
'ytick',linspace(0,1,numel(yTicks)),'yticklabel',yTicks)

This lets you set independent colors for major and minor X and Y grid lines, without overwriting the outer box. Even better, subsequent legend() commands will pick up the plot lines, not the manually drawn grid lines.
The trick is to make copies of the axes, then reverse their order in the figure's drawing hierarchy. Each copy of the axes can then draw its own set of grid colors and styles.
This strategy is compatible with subplot() and print().
function gridcolor(majorX, majorY, minorX, minorY)
ax1 = gca; %# get a handle to first axis
%# create a second transparent axis, same position/extents, same ticks and labels
ax2 = copyobj(ax1,gcf);
ax3 = copyobj(ax1,gcf);
delete(get(ax2,'Children'));
delete(get(ax3,'Children'));
set(ax2, 'Color','none', 'Box','off','YTickLabel',[],'YTickLabel',[],...
'GridLineStyle', '-',...
'XGrid','on','YGrid','on',...
'XMinorGrid','off','YMinorGrid','off',...
'XColor',majorX,'YColor',majorY);
set(ax3,'Box','off','YTickLabel',[],'YTickLabel',[],...
'MinorGridLineStyle','-',...
'XGrid','off','YGrid','off',...
'XMinorGrid','on','YMinorGrid','on',...
'XColor',minorX,'YColor',minorY);
set(ax1, 'Color','none', 'Box','on')
handles = [ax3; ax2; ax1];
c = get(gcf,'Children');
for i=1:length(handles)
c = c(find(c ~= handles(i)));
end
set(gcf,'Children',[c; flipud(handles)]);
linkaxes([ax1 ax2 ax3]);
end
subplot(211);semilogx([1:4000]);gridcolor('r','g','c','b');
subplot(212);semilogx(([1:4000]).^-1);gridcolor('r','g','c','b');