Is it possible to prodce a pcolor plot with 2 yaxis?
Consider the following example:
clear all
temp = 1 + (20-1).*rand(365,12);
depth = 1:12;
time =1:365;
data2 = 1 + (60-1).*rand(12,1);
time2 = [28,56,84,124,150,184,210,234,265,288,312,342];
figure;
pcolor(time,depth,temp');axis ij; shading interp
hold on
plot(time2,data2,'w','linewidth',3);
Instead of plotting the second dataset on the same y axis I would like it to placed on its own y-axis. Is this possible?
You need to add additional axes on the top of pcolor axes, match their position and then plot. You can set axes location on the top (X) and on the right (Y). Don't forget to link X axes if they suppose to match with LINKAXES.
pcolor(time,depth,temp');axis ij; shading interp
ax1 = gca;
%# new axes with plot
ax2 = axes('position',get(ax1,'position'),'color','none');
set(ax2,'YAxisLocation','right', 'XAxisLocation','top')
hold on
plot(ax2,time2,data2,'w','linewidth',3);
hold off
linkaxes([ax1 ax2], 'x');
I am not sure what you mean.
If you want same axes but different y values, try plotyy. If you want two different axes, try using the command subplot.
Related
I'm currently trying to plot a map from a .shp file and the result is not aesthetically pleasing:
minx=-75;
maxx=-68;
miny=-40;
maxy=-30;
cntry02=shaperead('cntry02', 'UseGeoCoords', true);
figure
geoshow(cntry02, 'FaceColor', [1 1 1]);
axis([minx-1 maxx+1 miny-1 maxy+1])
grid on
which produces
Is there a way to
1) plot all the grid (over the countries)?
2) plot the entire frame?
3) display S and W, instead of negative values of latitude and longitude?
I've been fighting with this problem all the morning. Thanks in advance.
You can download the .shp file from here.
http://openmap.bbn.com/svn/openmap/trunk/share/data/shape/cntry02/
For problem 1 and2, the reason is that the axes are always behind the plot. So one solution is to add new axes on the current one and display grid, box, and customized ticks.
For problem 3, I use regexprep to replace negative latitude with S suffix (idem for longitude). The only problem I have is that longitude 0 will be 0E, and latitude 0, 0N.
And here is the code:
figure;
axes;
geoshow(cntry02, 'FaceColor', [1 1 1]);
axis([minx-1 maxx+1 miny-1 maxy+1]);
axis off;
hold on; %hold to add new axes
axes('Color','none'); %specify no background, else default is here white
axis([minx-1 maxx+1 miny-1 maxy+1]);
grid on;
box on;
set(gca,'XTick', minx-1:2:maxx+1);
%compute x tick labels
xticks = num2str(minx-1:2:maxx+1);
xticks = regexprep(regexprep(xticks,'-([\d.]+)','$1W'), '\b[\d\.]+','$0E');
xticks_cell = cellstr(regexp(xticks,'\s+','split'));
set(gca,'XTickLabel',xticks_cell)
set(gca,'YTick', miny-1:2:maxy+1);
% compute y tick labels
yticks = num2str(miny-1:2:maxy+1);
yticks = regexprep(regexprep(yticks,'-([\d.]+)','$1S'), '\b[\d\.]+','$0N');
yticks_cell = cellstr(regexp(yticks,'\s+','split'));
set(gca,'YTickLabel',yticks_cell)
I'm trying to position MATLAB's ticks to line up with my grid, but I can't find a good way to offset the labels.
Also, if I run set(gca,'XTickLabel',1:10), my x tick labels end up ranging from 1 to 5. What gives?
You need to move the ticks, but get the labels before and write them back after moving:
f = figure(1)
X = randi(10,10,10);
surf(X)
view(0,90)
ax = gca;
XTick = get(ax, 'XTick')
XTickLabel = get(ax, 'XTickLabel')
set(ax,'XTick',XTick+0.5)
set(ax,'XTickLabel',XTickLabel)
YTick = get(ax, 'YTick')
YTickLabel = get(ax, 'YTickLabel')
set(ax,'YTick',YTick+0.5)
set(ax,'YTickLabel',YTickLabel)
Or if you know everything before, do it manually from the beginning:
[N,M] = size(X)
set(ax,'XTick',0.5+1:N)
set(ax,'XTickLabel',1:N)
set(ax,'YTick',0.5+1:M)
set(ax,'YTickLabel',1:M)
The marked answer works with a surf or mesh plot, however, I needed a solution which worked for a 2d plot.
This can be done by creating two axes, one to display the grid and the other to display the labels as follows
xlabels=1:1:10; %define where we want to see the labels
xgrid=0.5:1:10.5; %define where we want to see the grid
plot(xlabels,xlabels.^2); %plot a parabola as an example
set(gca,'xlim',[min(xgrid) max(xgrid)]); %set axis limits so we can see all the grid lines
set(gca,'XTickLabel',xlabels); %print the labels on this axis
axis2=copyobj(gca,gcf); %make an identical copy of the current axis and add it to the current figure
set(axis2,'Color','none'); %make the new axis transparent so we can see the plot
set(axis2,'xtick',xgrid,'XTickLabel',''); %set the tick marks to the grid, turning off labels
grid(axis2,'on'); %turn on the grid
This script displays the following figure :
I am trying to plot the wake velocity deficient behind an object at different streamwise positions (pos.1, 2 and 3) behind the object.
A rough sketch of how the graph should look like is shown below. The x-axis represents velocity and the y-axis is the coordinate normal to the flow.
How can I restart the x-axis such that the data of each position is plotted in it's own space, resembling it's actual position in the flow.
Easiest solution I think is to create all plots you need in horizontally arranged subplots, and then "beautify" according to your level of perfectionism ^_^
The "beautifications" I did in this case are:
For the axes in each subplot, switch the 'box' option off
Set the ytick to [] and color the y-axes white, of every y-axis except the leftmost one
create another axes object in the background without any axes labels, so that it appears that the subplots are really one plot
Here's the code:
%// Some bogus data
y = 0:0.1:4*pi;
x1 = sin(y);
x2 = sin(3*y);
x3 = sin(2*y).*sin(5*y);
%// Initialize figure window
figure(1), clf, hold on
%// Plot each plot on its own axes
subplot(1,3,3), hold on
plot(x3,y)
set(gca,...
'ytick' , [],...
'ycolor', 'w',...
'box' , 'off');
subplot(1,3,2)
plot(x2,y)
set(gca,...
'ytick' , [],...
'ycolor', 'w',...
'box' , 'off')
subplot(1,3,1)
plot(x1,y)
set(gca,...
'box', 'off') %// NOTE: don't kill these axes
%// Background axes
P = axes('parent', 1, 'xtick', [], 'ytick', []);
uistack(P, 'down', 10)
You could consider plotting your data on a single x-axis with an offset and changing the label of the x-axis ticks.
Consider your x-vector to be x_pos1 for the first position, your second and third would be similar but with an addition of an offset. E.g. offset = 15; x_pos2 = x_pos1+offset;
You can obtain and change your x-axis tick label by:
get(gca, 'xticklabel')
set(gca, 'xticklabel', yourLabelHere)
I have some points in a 'jet' colormap. The points have a coefficient that can go from 0 to 1, but usually they dont cover all the range, e.g 0.75-0.9.
When I plot those points I colour them so 0.75 is the lesser colour in the colormap and 0.9 is the maximum color in the colormap, so all the colormap is shown. What I want to do is show that in the colorbar also. When I plot the colorbar the labels on it go to 64, but I want them from 0.75 to 0.9. How can I do that?
EDIT
I don't think the code itself helps a lot but here it goes, just in case. In the colors variable I convert the ZNCC to the range of the colormap.
EDIT2
I found the reason why caxis is not working for me. Here is the code:
%this is why it doesnt work
im=imread('someimageyouwanttotest_inRGB.png')
imshow(im)
points=[1, 2;1 , 2 ;0.3,0.7]
ZNCC=points(3,:)
cmap=colormap('jet');
colors=cmap(round( ((1-min(ZNCC))+ZNCC-1).*(size(cmap,1)-1)/max((1-min(ZNCC))+ZNCC-1))+1,: );
hold on
for i=1:length(ZNCC)
plot(points(1,i),points(2,i),'.','Color',colors(i,:));
end
colorbar()
hold off
I think that is your code displays all your colours correctly then rather just set up the colour bar first on no image:
points=[1, 2;1 , 2 ;0.3,0.7]
ZNCC=points(3,:)
cmap=colormap('jet');
caxis([min(ZNCC) max(ZNCC)]);
colorbar();
hold on
%this is why it doesnt work
im=imread('someimageyouwanttotest_inRGB.png')
imshow(im)
colors=cmap(round( ((1-min(ZNCC))+ZNCC-1).*(size(cmap,1)-1)/max((1-min(ZNCC))+ZNCC-1))+1,: );
for i=1:length(ZNCC)
plot(points(1,i),points(2,i),'.','Color',colors(i,:));
end
hold off
I can't test it as I don't have imshow :/
If caxis is not working for you, you could store the return from colorbar - it is a handle to the colorbar object. Then you can set its properties, like 'YTick' and 'YLim'. The full list of properties you can set is the same as the Axes Properties (because the colorbar is just an axes object, after all).
Here is an example:
% Generate some random data
z = rand(10);
[x, y] = meshgrid(1:size(z, 1));
% Plot colour map
pcolor(x, y, z);
shading interp; % Comment out to disable colour interpolation
colormap jet;
% Setup colorbar
c = colorbar();
set(c, 'YTick', [0.75 0.875 1]); % In this example, just use three ticks for illustation
ylim(c, [0.75 1]);
It is only necessary to do this once, after you've finished plotting.
Edit: If you need the limits and ticks automatically from the data, then you can do something like
% Find the limits
lims = [min(z(:)) max(z(:))];
% Function for rounding to specified decimal places
dprnd = #(x, dps)round(x*(10.^dps))./(10.^dps);
% Generate ticks
nTicks = 5;
nDps = 2;
ticks = dprnd(linspace(lims(1), lims(2), nTicks), nDps);
set(c, 'YTick', ticks);
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)