I have this bar graph in MATLAB, created using the bar command:
I was wondering if there is any way to get rid of empty spaces
between 2478 and 2886, and between 4314 and 5130
If I can get the bars to have an equal amount of space in between them that would be perfect.
As described in the documentation of bar,
bar(x,y) draws the bars at the locations specified by x.
which means that this behavior is intended: Each bar is drawn at the exact position specified by x.
To get equally spaced bars, you can use the categorical function, which converts x to a data type which is intended for discrete categories.
That way, you tell MATLAB that x is not a numerical vector where x(i) is the x-coordinate of the i-th element, but rather a simple label for that value.
bar(categorical(x), y)
Your bars are drawn in the locations of your x data, and are spaced accordingly.
You could plot against [1, 2, 3, ..., 13] and re-label the axes like so
Example data:
x = [1886,2070,2274,2478,2886,3090,3294,3498,3702,3960,4110,4314,5130];
y = rand(1,13)*5 + 32;
Plotting
bar( 1:numel(y), y );
set( gca, 'XTickLabel', x );
Related
I produced a plot that contains 50 curves and each of them corresponds to a specific value of a parameter called "Jacobi constant", so I have 50 values of jacobi constant stored in array called jacobi_cst_L1:
3.000900891023230
3.000894276927840
3.000887643313580
3.000881028967010
3.000874419173230
3.000867791975870
3.000861196034850
3.000854592397690
3.000847948043080
3.000841330136040
3.000834723697250
3.000828099771820
3.000821489088600
3.000814922863360
3.000808265737810
3.000801695858850
3.000795067776960
3.000788475204760
3.000781845363950
3.000775192199620
3.000768609354090
3.000761928862980
3.000755335851910
3.000748750854930
3.000742084743060
3.000735532899990
3.000728906460450
3.000722309400740
3.000715644446600
3.000709016645110
3.000702431180730
3.000695791284050
3.000689196186970
3.000682547292110
3.000675958537960
3.000669315388860
3.000662738391370
3.000656116141060
3.000649560630930
3.000642857256680
3.000636330415510
3.000629657944820
3.000623060310100
3.000616425935580
3.000609870077710
3.000603171772120
3.000596554947660
3.000590018845460
3.000583342259840
3.000576748353570
I want to use a colormap to color my curves and then show in a lateral bar the legend that show the numerical values corresponding to each color of orbit.
By considering my example image, I would want to add the array of constants in the lateral bar and then to color each curve according the lateral bar.
% Family of 50 planar Lyapunov orbits around L1 in dimensionless unit
fig = figure;
for k1 = 1:(numel(files_L1_L2_Ly_prop)-2)
plot([Ly_orb_filt(1).prop(k1).orbits.x],[Ly_orb_filt(1).prop(k1).orbits.y],...
"Color",my_green*1.1); hold on %"Color",my_green*1.1
colorbar()
end
axis equal
% Plot L1 point
plot(Ly_orb_filt_sys_data(1).x,Ly_orb_filt_sys_data(1).y,'.',...
'color',[0,0,0],'MarkerFaceColor',my_green,'MarkerSize',10);
text(Ly_orb_filt_sys_data(1).x-0.00015,Ly_orb_filt_sys_data(1).y-0.0008,'L_{1}');
%Primary bodies plots
plot(AstroData.mu_SEM_sys -1,0,'.',...
'color',my_blue,'MarkerFaceColor',my_blue,'MarkerSize',20);
text(AstroData.mu_SEM_sys-1,0-0.001,'$Earth + Moon$','Interpreter',"latex");
grid on;
xlabel('$x$','interpreter','latex','fontsize',12);
ylabel('$y$','interpreter','latex','FontSize',12);
How can I color each line based on its Jacobi constant value?
You can use any colour map to produce a series of RGB-triplets for the plotting routines to read (Or create an m-by-3 matrix with elements between 0 and 1 yourself):
n = 10; % Plot 10 lines
x = 1:15;
colour_map = jet(n); % Get colours. parula, hsv, hot etc.
figure;
hold on
for ii = 1:n
% Plot each line individually
plot(x, x+ii, 'Color', colour_map(ii, :))
end
colorbar % Show the colour bar.
Which on R2007b produces:
Note that indexing into a colour map will produce linearly spaced colours, thus you'll need to either interpolate or calculate a lot to get the specific ones you need. Then you can (need to?) modify the resulting colour bar's labels by hand to reflect your input values. I'd simply use parula(50), treat its indices as linspace(jacobi(1), jacobi(end), 50) and then my_colour = interp1(linspace(jacobi(1), jacobi(end), 50), parula(50), jacobi).
So in your code, rather than using "Color",my_green*1.1 for each line, use "Color",my_colour(kl,:), where my_colour is whatever series of RGB triplets you have defined.
I have a matrix, A, that contains 50 rows and 4 columns, and the entries are filled with integers. My interest is to construct a stacked 3D bar plot from this data. However, using bar3(A,'stacked') creates a row of 50 bars, whereas I want the bars to be plotted at the coordinates of a grid of size 5 (vertical) x 10 (horizontal). So the first bar in the row would be at location (1,1), second bar at (1,2), 11th bar at (2,1) and so on until the 50th bar which would be at (5,10). I can't seem to find a way to do this in Matlab, is this possible at all?
Thank you in advance!
I agree with #cris, there are better ways to represent your data. However, something like this would work if you still want to do use a 3D bar plot:
figure
hold on
for i = 1:5
Ai = A(10*(i-1)+1:10*i,:);
h = bar3(1:10,Ai,'stacked');
for ih = 1 :length(h)
x = get(h(ih), 'Xdata');
set(h(ih), 'Xdata', x+i-1);
end
end
view(3)
Say that I have a matrix Z with some values, and I want to illustrate it by a plotting the values in Z by height. The first solution comes to mind is a surface, but using surf and similar functions with small matrices doesn't look good.
So I thought about using something like a 3D bar plot with bar3. But the problem is that this function always sets the color by the group and not by height, and I can't get it to do so.
Here is an example:
Z = peaks(5);
subplot 121
surf(Z)
title('Surface look bad')
subplot 122
bar3(Z)
title('The color is not by height')
I tried to look for the color properties in the handles returned by bar3 (like CData and FaceColor) but got lost with all the values and how they relate to the bars themselves.
Ultimately, I would like to have a general solution that for 2 matrices Z and C I can create a 3D bar plot with bars in height given by Z and color given by C.
How can I do so?
The function bar3 returns a surface object, one for each group (i.e. one for each color), so all the bars in one group are essentially plotted as one 'broken' surface. This is explained very good in this answer, so I won't repeat it here.
Instead, I'll get to the solution for this specific problem. The relevant property of the surface is CData. When we create the bar plot, each surface's CData is assigned with a matrix in some size (we'll get to this) that is all equal one value. A different value for each surface. This is how the figure as a whole translates its color map to the color of the groups.
As written above (and elaborated in the linked answer), each group represented by a surface, so it takes a whole matrix to define the color at each point of the surface. The first thing we want to do is to get this matrix size:
Z = peaks(5);
bar_h = bar3(Z);
% we take only the first one, but they are all the same size:
cdata_sz = size(bar_h(1).CData)
cdata_sz =
30 4
CData has always 4 columns (see here why), and the number of rows is always 6*number of groups. This is because it takes 5 vertices to create one closed rectangle with an area object (the last vertex is like the first one) and one line is for spacing between the bars with NaNs, so they will look separated.
Next, we need to enlarge our original colormap (which is the same size of Z) to fit CData in the right way. Essentially, we just want to repeat the same value for all vertices that belong to the same bar. Assuming Z is also our color data (i.e. we color by height) we do:
z_color = repelem(Z,6,4)
Now we need to split our z_color to different cells in the number of our groups. Each cell will contain the coloring data for one surface object:
z_color = mat2cell(z_color,cdata_sz(1),ones(1,size(Z,2))*cdata_sz(2));
And finally, we apply the new color data to the bar plot:
set(bar_h,{'CData'},z_color.')
As a bonus, if we want to remove all zero values from our bar, it can be done easily by setting them to NaN:
Z(abs(Z)<eps) = nan;
C(isnan(Z)) = nan; % if we use a colormap C different from Z
All the above could be boiled down to this handy function:
function bar_h = Cbar3(Z,C,b,y)
% Z - The data
% C - CData (if other then Z values)
% b - Minimum absolute value to keep colored
% y - y-axis values to order the data by
if nargin<2, C = Z; end
if nargin<3 || isempty(b), b = 0; end
Z(abs(Z)<b) = nan;
C(isnan(Z)) = nan;
if nargin<4
bar_h = bar3(Z);
else
bar_h = bar3(y,Z);
end
cdata_sz = size(bar_h(1).CData);
z_color = repelem(C,6,4);
z_color = mat2cell(z_color,...
cdata_sz(1),ones(1,size(Z,2))*cdata_sz(2));
set(bar_h,{'CData'},z_color.')
end
Example of usage:
subplot 121
Z = peaks(30);
Cbar3(Z,Z,0.5);
pbaspect auto
shading flat % just to get a cleaner look
title('Cbar3 using height as color')
subplot 122
Cbar3(Z,rand(size(Z)),0.5);
pbaspect auto
shading flat % just to get a cleaner look
title('Cbar3 using random as color')
Result:
This is a partial answer.
The case of using the bar height as color is covered by the official MATLAB documentation. Essentially the example code boils down to:
function q45423394
hB = bar3(peaks(25)); colorbar;
for indE = 1:numel(hB)
hB(indE).CData = hB(indE).ZData;
end
All you need to do afterwards is make sure that the colormap is the one you want.
While I find EBH's solution aesthetically more pleasing, here there is a simpler solution: interpolation
z = peaks(5);
[x,y]=meshgrid(1:0.1:size(z,1),1:0.1:size(z,2));
zn=interp2(z,x,y,'nearest');
% plot it
surf(zn,'edgecolor','none','facecolor','interp')
I am trying to plot a set of horizontal and vertical boxplots on the same axes in Matlab R2011b. Using the usual hold on command does not seem to work; only the second set of boxplots is shown. My code is as follows:
bv = boxplot(x,yGrp,'orientation','vertical');
hold on
bh = boxplot(y,xGrp,'orientation','horizontal','position',yPos);
yGrp and xGrp, the grouping index variables are specifically set to be in the range of the y and x datasets, respectively, so that the two plots should naturally have a similar set of values. That is, my x variables spans the range 0-0.05 and my y-variable spans the range 0-1, so yGrp contains a set of categorical numbers between 0 and 1 and xGrp contains bin numbers spanning the range 0-0.05. Similarly, yPos is chosen to span the expected 0-1 range of the vertical axes.
Removing the 'position' argument in the second boxplot call or trying to use simple integer variables does not help. If plotting in separate windows my boxplots look good, but I cannot combine them. What am I doing wrong?
The problem is in axes limits (xlim and ylim). Briefly your 1st boxplots exist but hidden out of axes.
When you plot the second boxplot, it set its own limits ignoring the 1st boxplot. In addition, boxplot by default sets position (y values for horizontal orientation) as 1:number_of_groups, but label them according to your groups. So the ylim will be [0.5 number_of_groups+0.5].
Since your x values are between 0 and 0.05, they are not visible.
As a solution set the limits manually considering this boxplot behavior:
x = rand(10,1)/20;
xg = randi(2,10,1)/40;
y = rand(10,1);
yg = randi(2,10,1)/2;
bv = boxplot(x,xg,'orientation','vertical');
xlim manual
hold on
bh = boxplot(y,yg,'orientation','horizontal');
hold off
xlim([0 2.5])
ylim([0 2.5])
When you set position parameter it determines the values instead of 1:number_of_groups. You can set them close to the range of x.
I have a question about using the area function; or perhaps another function is in order...
I created this plot from a large text file:
The green and the blue represent two different files. What I want to do is fill in the area between the red line and each run, respectively. I can create an area plot with a similar idea, but when I plot them on the same figure, they do not overlap correctly. Essentially, 4 plots would be on one figure.
I hope this makes sense.
Building off of #gnovice's answer, you can actually create filled plots with shading only in the area between the two curves. Just use fill in conjunction with fliplr.
Example:
x=0:0.01:2*pi; %#initialize x array
y1=sin(x); %#create first curve
y2=sin(x)+.5; %#create second curve
X=[x,fliplr(x)]; %#create continuous x value array for plotting
Y=[y1,fliplr(y2)]; %#create y values for out and then back
fill(X,Y,'b'); %#plot filled area
By flipping the x array and concatenating it with the original, you're going out, down, back, and then up to close both arrays in a complete, many-many-many-sided polygon.
Personally, I find it both elegant and convenient to wrap the fill function.
To fill between two equally sized row vectors Y1 and Y2 that share the support X (and color C):
fill_between_lines = #(X,Y1,Y2,C) fill( [X fliplr(X)], [Y1 fliplr(Y2)], C );
You can accomplish this using the function FILL to create filled polygons under the sections of your plots. You will want to plot the lines and polygons in the order you want them to be stacked on the screen, starting with the bottom-most one. Here's an example with some sample data:
x = 1:100; %# X range
y1 = rand(1,100)+1.5; %# One set of data ranging from 1.5 to 2.5
y2 = rand(1,100)+0.5; %# Another set of data ranging from 0.5 to 1.5
baseLine = 0.2; %# Baseline value for filling under the curves
index = 30:70; %# Indices of points to fill under
plot(x,y1,'b'); %# Plot the first line
hold on; %# Add to the plot
h1 = fill(x(index([1 1:end end])),... %# Plot the first filled polygon
[baseLine y1(index) baseLine],...
'b','EdgeColor','none');
plot(x,y2,'g'); %# Plot the second line
h2 = fill(x(index([1 1:end end])),... %# Plot the second filled polygon
[baseLine y2(index) baseLine],...
'g','EdgeColor','none');
plot(x(index),baseLine.*ones(size(index)),'r'); %# Plot the red line
And here's the resulting figure:
You can also change the stacking order of the objects in the figure after you've plotted them by modifying the order of handles in the 'Children' property of the axes object. For example, this code reverses the stacking order, hiding the green polygon behind the blue polygon:
kids = get(gca,'Children'); %# Get the child object handles
set(gca,'Children',flipud(kids)); %# Set them to the reverse order
Finally, if you don't know exactly what order you want to stack your polygons ahead of time (i.e. either one could be the smaller polygon, which you probably want on top), then you could adjust the 'FaceAlpha' property so that one or both polygons will appear partially transparent and show the other beneath it. For example, the following will make the green polygon partially transparent:
set(h2,'FaceAlpha',0.5);
You want to look at the patch() function, and sneak in points for the start and end of the horizontal line:
x = 0:.1:2*pi;
y = sin(x)+rand(size(x))/2;
x2 = [0 x 2*pi];
y2 = [.1 y .1];
patch(x2, y2, [.8 .8 .1]);
If you only want the filled in area for a part of the data, you'll need to truncate the x and y vectors to only include the points you need.