Problem: When attempting to export a polygon rendered with the patch command in MATLAB with fig2plotly, the final output is lacking the specified face colours.
Perhaps a demonstration would help. Take the following vertices and faces to define a cube (lifted from the MATLAB documentation):
vert = [0 0 0;1 0 0;1 1 0;0 1 0;0 0 1;1 0 1;1 1 1;0 1 1];
fac = [1 2 6 5;2 3 7 6;3 4 8 7;4 1 5 8;1 2 3 4;5 6 7 8];
And render it with the patch command, adding some colour information to the faces:
patch('Vertices',vert,'Faces', fac, 'FaceVertexCData',hsv(8),'FaceColor','interp')
And view it in 3D:
view(3)
axis vis3d
This gives a nice cube with interpolated colour values on the surface.
Now, if we attempt to export it to Plotly with the fig2plotly command:
fig2plotly(gcf)
It returns an empty cube (plotly link):
In other words, the line information has been captured, but not the faces. Even if we attempt to preserve the MATLAB styling, we still loose the face information:
fig2plotly(gcf, 'strip', false)
Any suggestions?
Improved support for patches has been added to ver. 2.2.9 of the wrapper (https://github.com/plotly/MATLAB-Online).
You can toggle this improved patch handling by setting the TriangulatePatch default to true within the plotlyfig.m file.
(https://github.com/plotly/MATLAB-Online/blob/master/plotly/plotlyfig.m#L61)
Colour gradients are not yet supported but the patches themselves should now render. Colour modifications can be made by manually modifying the attributes of the plotlyfig object or by using the web interface.
Related
I got the following problem: I'm working on an algorithm and the output will be an arbitrary polygon. The polygon can be concave, have holes in it and also have vertices with edges that have an angle of 180 degree.
I need to triangulate said polygon with and without additional vertices inside it. Can the delaunay triangulation handle this, especially if I only have the polygon without vertices inside? I might be able to avoid holes inside the polygon, if that eases things.
Thanks for reading
You might have a look at these Fade2D examples:
https://www.geom.at/example4-zones-defined-areas-in-triangulations/
https://www.geom.at/boolean-operations-on-polygons-with-holes/
The student license is free.
You can do that using a constrained triangulation (Delaunay or not) to triangulate a polygon. There is an example using CGAL here.
You can use Triangle.
Running Triangle via the command line, you create an ASCII .poly file that specifies the vertices and edges of the input (i.e., your polygon) as well as any holes in the domain. Each hole is defined by its xyz location. For example, if I have a square domain with a triangular hole inside it, my input could look like:
7 2 0 0 # 7 vertices
1 1 -1
2 1 1
3 -1 1
4 -1 -1
5 -.5 -.5
6 .5 -.5
7 0 .5
7 0 # 7 segments: four for the square and three for the hole
1 1 2
2 2 3
3 3 4
4 4 1
5 5 6
6 6 7
7 7 5
1 # 1 hole
1 0.0 0.0
If you want to refine the mesh (i.e., add vertices inside), you can use either the -a option (limiting the maximum area of a triangle) or the -q option (controlling the quality of the triangles produced but not directly limiting the size). The documentation on command line switches is here.
I've asked this question on Mathwork's site so if cross-posting isn't allowed let me know and I'll delete this.
I'm trying to render small objects and large objects together in MATLAB. I'm using the camera commands to restrict my field of view such that I can see both. However, when I do that, the hidden line removal fails on the small objects. I would have thought that hidden line removal would have been done at machine precision for floats, but it appears not. Is this a function of my graphics card or can I work around this?
The code below is the minimum example I could come up with. Plotted on an axis with default limits, the hidden line removal works fine (left) When the axis is set to large extents (compared to the object) the line removal fails (middle). When I make the axis disappear things are fine again (right).
For this example, I can just hide the axis and the output looks correct. But for what I'm actually trying to do, that's not an option. Any suggestions or can someone point me to the proper limit between the smallest and largest objects in a scene that will properly render?
The code to generate the spheres above is below. Thanks in advance!
Images as generated by MATLAB 2018A
clearvars
F1 = figure(1);
clf
set(F1,'color',[1 1 1],'Renderer','opengl'); % have to enable this to clip surfaces behind the camera
for step = [2 1 3] % out of order because the axis in case 2 is trying to hide the first plot
subplot(1,3,step)
view(gca,3);
camproj(gca,'Perspective'); % have to enable this to clip surfaces behind the camera
[Xs,Ys,Zs] = sphere(20);
r = 30e-6;
surf(gca,Xs*r,Ys*r,Zs*r);
axis(gca,'equal');
% three different behaviors, pick a number 1, 2, or 3
switch step
case 1 % this plots the sphere correctly
%axis([-2 2 -2 2 -2 2]);
%axis off
case 2 % this messes up the hidden line removal
axis([-2 2 -2 2 -2 2]);
%axis off
case 3 % removing the axis walls fixes things again
axis([-2 2 -2 2 -2 2]);
axis off
end
% put viewpoint on unit sphere
camera_pos = get(gca,'CameraPosition');
mag_camera_pos = sqrt(sum(camera_pos.^2));
camera_pos = camera_pos / mag_camera_pos;
set(gca,'CameraPosition',camera_pos);
final_angle = 2.5*atand(r/1);
set(gca,'CameraViewAngle',final_angle);
end
drawnow
I'm running a simulation that describes activity at the front and back of a 2D, square lattice. the front and back are described for example by:
front= [-1 1 -1 0 1 0 1 2 -2 1 ];
back = [ 1 0 0 0 2 0 1 -2 -2 1 ];
each number indicates different activity on the lattice.
I want to plot this interactively so that each value in the lattice will be marked by a different marker and color and the plot will be updated every iteration.
So far I have something like:
% the upper and lower edges of the lattice
figure (1)
hold on
plot(linspace(1,100,10),10*ones(1,10),'k'); %front
plot(linspace(1,100,10),1*ones(1,10),'k'); %back
% the front and back when are equal 0 zero (initial condition)
plot(100*ones(1,10),1:10,'ob','markersize',10); % front
plot(1*ones(1,10),1:10,'ob','markersize',10); % back
xlim([-1 101])
ylim([-1 11])
This marks the initial setup of the system I'm working on, plot it to see what I'm referring to.
now in each iteration I want to view the circles change colors for different values, for example:
figure (1)
ind=find(front==1);
if (isenum(ind)==0)
plot(100*ones(1,length(ind)),ind,'or','markerfacecolor','r');
end
This is done 10 times, for 5 values at the front and 5 at the back, and is quite heavy on the simulation
I wish to find a way that I can span the entire vector front/back on the lattice with "one go" and have different markers assigned to each value. I manage to do it with imagesc, however, I lose the graphics I want to keep while piloting the markers (I wish to add arrows and other stuff later as well). does anyone have any experience with these kind of things?
Could you please write a MATLAB Script to animate the motion of the rolling disk for two complete rotations, also showing (as a trace) the trajectory of the point on the rim. Take: radius of the disk equal to 10 units, radius of the point is also equal to 10 units.
Produce a static plot for your system, showing the speed of the rim point using the “quiver”
command.
Here is the code so far:
figure;
%XX=[0 2 4 5 0];
%YY=[1 0 1 5 1];
NN=100;
RR=2;
th=linspace(0,360,NN+1)*pi/180;
XX=RRcos(th);
YY=RRsin(th);
h=patch('XData',XX,... 'YData',YY,'FaceColor',[1 0 0]);
axis([0 10 -2 8]);
axis square
N=100; dX=5/N;
for ii=1:N XX=XX+dX;
set(h,'XData',XX);
drawnow;
pause(0.1)
end
just add one timer and then inside the timer function change the position of circle according the rotation and transform ( if you don't know how to change position then go through with basic geometry concept).
I would like to plot a series of rectangular pulse to a vector data input. The plot profile would create a rising edge of the pulse for a positive number and create the falling edge for the negative of that number. The plot should separate color for each represented number.
For example, if vector input X is [1 -1 2 -2 3 4 1 -4 -1 -3]
Amplitude of data ‘1’ is 5,
Amplitude of data ‘2’ is 4,
Amplitude of data ‘3’ is 3 and
Amplitude of data ‘4’ is 2
So, the input X got index from t(1) to t(10). The output of plot or chart should look like the inserted image
How would I can write a MATLAB code for this work?
Thank you.
B.Bundit
The plot is very small but I think you want something like bar in matlab. Documentation is here. If the vector that you have is changes then you can create a vector of values for plotting using cumsum.
X=[1 -1 2 -2 3 4 1 -4 -1 -3];
Xplot=cumsum([5,X(2:end)]); % //so 5 will be your initial value
Since the plot you give above has different widths of bars, you would also need a vector of the center of each data point and the width of each data point.
means= [1 2 3 4 5 6 7 8 9 10];
widths=[1 1 1 1 1 1 1 2 1 1];
For different color bar plots you can do:
colors=['r','g','k','b','c','m','y','r','g','k'];
for i=1:length(X)
h=bar(means(i),Xplot(i),widths(i));
if i==1, hold on; end
set(h,'FaceColor',colors(i));
end
% //This will label each bar, or you could define your axes before the loop
set(gca,'XTickLabel',means);
You can explore other properties to set here. The class barseries does not have a FaceAlpha property so I'm not sure if you can make them transparent. You could however set the FaceColor to none and have the EdgeColor be set to your color of choice. Note that edge color is specified by an RGB triplet and not a letter code.
You may also need to resort your data by width, so that the widest bars are plotted last and are thus on top. This would look like this:
[widths_sorted,sort_idx]=sort(widths,'ascending');
Xplot_sorted=Xplot(sorted_idx);
means_sorted=means(sorted_idx);