Is there a method of aligning tick labels?
I have a figure that has two y axes where the values vary greatly. I would like to align the tick labels so that each value shown on one y label matches up with a value on the opposite ylabel. For example:
data1 = 1+ (12-1).*rand(365,1);
data2 = 1 + (700-1).*rand(365,1);
time = 1:365;
figure(1);
ax1 = axes('position',[0.05 0.5 0.22 0.37]);
plot(time,data1,'k','linewidth',1);
ylabel('label 1');
pos=double(get(ax1,'position'));
ax2=axes('position',pos,'color','none','YAxisLocation','right','xtick',[])
hold on;
plot(time,data2,'r','linewidth',1,'parent',ax2);
ylabel(ax2,'label 2');
Here I would like the second y axis to have the same number of ticks as the first y axis as well as the same spacing between them. How can I achieve this?
Use plotyy instead of plot, it handles this for you:
plotyy(time, data1, time, data2);
You can set the y axis limits and tick locations explicitly:
ylim(ax1,[lowerBound upperBound])
set(ax1,'ytick',[tick1 tick2 tick3 tick4])
This can let you fine tune the tick locations for a particular plot. It makes zooming and panning less functional, since the ticks are often left behind.
Related
I'm trying to display a discrete plot with values on the x-axis that are not equally space but I want them to appear equally spaced. I would like a stem plot with the first stick not on the y-axis, and I'd also like to have an horizontal dashed line at y=1.
So far here is what I tried.
x = [10 50 150 3000];
y = [.6 .754 .853 .954];
xv = [1 2 3 4];
stem(xv,y);
set(gca,'XTickLabel',x);
Unfortunately, this is not what I expected. The value on the x-axis are not right and the sticks start on the y-axis and end on the figure edge.
How can I fix this?
EDIT: I initially forgot the horizontal dashed line. Added this.
You just need two tiny additions:
x = [10 50 150 3000];
y = [.6 .754 .853 .954];
xv = [1 2 3 4];
stem(xv, y);
xlim([min(xv)-1 max(xv)+1]); % <--
set(gca, 'xtick', xv); % <--
set(gca, 'xticklabel', x);
You (also) need to explicitly set the xtick option, so that only these ticks are drawn, and no other.
With xlim, you can manipulate the x-axis limits. (Left and right limit might be modified to your needs.)
To add the horizontal dashed line, just add the following at the end:
hold on;
plot([min(xv)-1 max(xv)+1], [1 1], 'k--');
hold off;
(Start and end points of the line might be modified to your needs.)
From Matlab R2018b on, you could also use yline.
The output then looks like this:
When you have a sequence of values that you want to plot equally spaced without any special treatment to what each value actually is, you're essentially defining a set of categories.
MATLAB is good at handling these nicely without any extra trickery to lay them out uniformly on your axes if you declare the values explicitly as categorical.
All you need, therefore, is:
x = [10 50 150 3000];
y = [.6 .754 .853 .954];
stem(categorical(x),y);
yline(1,'--');
ylim([0 1.5]) % Make some space on the y-axis so the horizontal line doesn't sit on the top edge
I want to set the limit for X axis in this plot from 0 to 325. When i am using xlim to set the limits (commented in the code). It doesn't work properly. When i use xlim, the entire structure of plot changes. Any help will be appreciated.
figure
imagesc(transpose(all_area_for_visual));
colormap("jet")
colorbar('Ticks',0:3,'TickLabels',{'Home ','Field','Bad house','Good house'})
xlabel('Time (min)')
tickLocs = round(linspace(1,length(final_plot_mat_missing_part(2:end,1)),8));
timeVector = final_plot_mat_missing_part(2:end,1);
timeForTicks = (timeVector(tickLocs))./60;
xticks(tickLocs);
xticklabels(timeForTicks);
%xlim([0 325]);
ylabel('Car identity')
yticks(1:length(Ucolumnnames_fpm))
yticklabels([Ucolumnnames_fpm(1,:)])
If I get you right, you want to plot only part of the data in all_area_for_visual, given by a condition on tickLocs. So you should first condition the data, and then plot it:
% generate the vector of x values:
tickLocs = round(linspace(1,length(final_plot_mat_missing_part(2:end,1)),8));
% create an index vector (of logicals) that marks the columns to plot from the data matix:
validX = tickLocs(tickLocs<=325);
% plot only the relevant part of the data:
imagesc(transpose(all_area_for_visual(:,validX)));
% generate the correct ticks for the data that was plotted:
timeVector = final_plot_mat_missing_part(2:end,1);
timeForTicks = (timeVector(tickLocs(validX)))./60;
xticks(tickLocs(validX));
% here you continue with setting the labels, colormap and so on...
imagesc puts the data in little rectangles centered around integers 1:width and 1:height by default. You can specify what the x and y locations of each data point by adding two vectors to the call:
imagesc(x,y,transpose(all_area_for_visual));
where x and y are vectors with the locations along the x and y axes you want to place the data.
Note that xlim and xticks don’t change the location of the data, only the region of the axis shown, and the location of tick marks along the axis. With xticklabels you can change what is shown at each tick mark, so you can use that to “fake” the data locations, but the xlim setting still applies to the actual locations, not to the labels assigned to the ticks.
I think it is easier to plot the data in the right locations to start with. Here is an example:
% Fake your data, I'm making a small matrix here for illustration purposes
all_area_for_visual = min(floor(cumsum(rand(20,5)/2)),3);
times = linspace(0,500,20); % These are the locations along the time axis for each matrix element
car_id_names = [4,5,8,15,18]; % These are the labels to put along the y-axis
car_ids = 1:numel(car_id_names); % These are the locations to use along the y-axis
% Replicate your plot
figure
imagesc(times,car_ids,transpose(all_area_for_visual));
% ^^^ ^^^ NOTE! specifying locations
colormap("jet")
colorbar('Ticks',0:3,'TickLabels',{'Home ','Field','Bad house','Good house'})
xlabel('Time (min)')
ylabel('Car identity')
set(gca,'YTick',car_ids,'YTickLabel',car_id_names) % Combine YTICK and YTICKLABEL calls
% Now you can specify your limit, in actual time units (min)
xlim([0 325]);
In generating plots with Matlab, when both the x and y minimum are zero, I prefer to have only one zero marking the origin rather than denoting it on both axes.
Matlab defaults to the latter, like so
Whereas I want something more like this
This can be done manually, but I'm trying to automate the process. Removing the x and y tick labels for 0 are obviously easy enough. However, I can't seem to access any handle for the position of the axis tick labels to properly position a text box for the 'new origin'. It seems the tick label offsets from the x and y axes may be somewhat constant in a given figure (in physical units, not normalized units), but I don't know if this is a standard across all figures or axes.
Any ideas?
I'm running Matlab 2014b.
Here's a simple way to do that:
% somthing to plot:
x = 0:0.1:2*pi;
y = abs(sin(x)+cos(x));
plot(x,y)
% get the handle for the current axes:
ax = gca;
% get the position of the zero tick on y-axis:
zeroYtick = ax.YAxis.TickValues==0;
% remove it (tick and lable)
ax.YAxis.TickValues(zeroYtick) = [];
The result:
If you want the 0 to be offset a little to the left, so it will be at the corner of the plot, you can use annotation:
% get the position of the zero tick on x-axis:
zeroXtick = ax.XAxis.TickValues==0;
% remove it (tick and lable)
ax.XAxis.TickValues(zeroXtick) = [];
% place a new zero at the origin:
dim = [0.1 0.01 0.1 0.1];
annotation('textbox',dim,'String','0',...
'FitBoxToText','on','LineStyle','none')
And you will get:
The advantage in annotation is that the origin always placed relative to the corner of the axes, and you don't need to know the values of the axes ticks to properly offset it.
EDIT:
For pre 2016a version you can use the following (I wrote it a little more compact):
ax = gca;
% remove the zero tick on y-axis (tick and lable):
ax.YTick(ax.YTick==0) = [];
% remove the zero tick on x-axis (tick and lable):
ax.XTick(ax.XTick==0) = [];
% place a new zero at the origin:
dim = [0.1 0.01 0.1 0.1];
annotation('textbox',dim,'String','0',...
'FitBoxToText','on','LineStyle','none')
EDIT 2:
Another option to keep the 0 in place is to stick it to the axes. this is done by replacing the Parent with the axes handle. First, we need a handle to the annotation (continuing from the last edit):
t = annotation('textbox',dim,'String','0',...
'FitBoxToText','on','LineStyle','none');
then we switch the Parent and set the new position:
t.Parent = ax;
t.Position(1:2) = -[0.2 0.1];
and finally, we super-glue it by converting the Units to pixels:
t.Units = 'Pixels';
The following will exclude the first tick on yaxis without shifting the graph at all. You can ensure that the correct item is being removed by setting the axis limits, ylim([0,upper_limit]) prior to removing the first one, or manually setting your yTicks, set(h,'yTick',my_ticks). Note that yTick changes the position of the ticks, while yTickLabel will change the text appearing at each position of yTick
h = plot([0,1],[0,1]);
yTicks = get(h,'yTick');
set(h,'yTick',yTick(2:end));
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 can add 2 y-axis to a octave/matlab plot but when I try and add the x-axis at the bottom of the plot with xlabel('Frequency in Hz') it doesn't show up
[ax h1 h2]=plotyy(xx,yy,xx,yy2); %plot two y axes and 1 x-axis
axes(ax(1)); ylabel('Phase Angle in degrees');
axes(ax(2)); ylabel('Amplitude');
Anybody know how to fix this so the x-axis will also show up
I'm using octave 3.2.4 / matlab
Make sure to call xlabel() after referencing one of the specific axes on the plot. You just need to do it once, but because of the double axis, invoking x-label outside of a specific axis context won't work. The following works for me just fine in Octave 3.2.4.
xx = [1,2,3];
yy = [10,11,12];
yy2 = [-10,-11,-12];
[ax h1 h2]=plotyy(xx,yy,xx,yy2);
axes(ax(1)); xlabel('Frequency in Hz'); ylabel('Phase Angle in degrees');
axes(ax(2)); ylabel('Amplitude');
In order to add a label (either xlabel or ylabel) to certain axes you can also pass this axes reference as first argument of the command call. This way you will also guarantee that you are on the right context as #EMS pointed out.
xx = [1,2,3];
yy = [10,11,12];
yy2 = [-10,-11,-12];
[ax h1 h2]=plotyy(xx,yy,xx,yy2);
xlabel(ax(1),'Frequency in Hz'); ylabel(ax(1),'Phase Angle in degrees');
ylabel(ax(2),'Amplitude');
This is also better in terms of performance, as in case you call axes several times, you will see how everything slows considerably down.