結果:
Hi, Im new to here. I wanted to ask for assitance in plotting ellipsoids onto XYZ plots based on Excel data. The data shows details for seismic events but the analysis needs to be just looking into the data as points on a XYZ graph. I have no experience with Matlab and any help would be greatly appreciated.
The first column is to identify the point; Column B is the time of the event; Column C-E is the location of the point. Column D reflects the amount of energy released. Colums G-R are for eigenvalues and eigenvectors.
Each ellipsoid is described by the 3 semi-major axes, named 1, 2, 3 in our file.
The 3 columns Axis 1, Axis 2, Axis 3 are the length (eigenvalues) of the 3 semi-major axis in metres.
The next 9 columns define the semi-major axis vectors (eigenvectors), so for example [Vector 1 X, Vector 1 Y, Vector 1 Z] define the 3 direction cosines (XYZ) of the Axis 1 vector.
So for example:
Axis 1 of the ellipsoid for Trigger ID 1 (screenshot below) has half-length 61m. It has vector orientation [-0.97, -0.06, 0.25], which can be imagined as a 3D line between point [0,0,0] and [-0.97, -0.6, 0.25].
I want to see if its possible to write something to convert them into XYZ points on an ellipsoid surface.
Or Find the Max value for Axis 1, Axis 2, Axis 3 – which tells you the maximum location uncertainty in metres for each event. This will normally be Axis 3.
If you then look at Vector 3 Z it will usually be close to +1.0 or -1.0 (which are the maximum and minimum values). If it is close to +/- 1.0 it means that the axis is near vertical. If it is close to 0.0 then it is horizontal.
Surface monitoring networks normally have the greatest location uncertainty in depth.
These specific eigenvectors mean:
[X=0.0, Y=+/-1.0, Z=0.0] would be North/South (ie: the Y component is largest).
[X=+/-1.0, Y=0.0, Z=0.0] would be East/West (ie: X biggest)
[X=0.0, Y=0.0, Z=+/-1.0] would be vertical
I have 600+ rows and the aim is to look at the elliposids to make interpretations on there orientation and their distrubtion. Thank you for any help.
Hi
I have hundreds of Lidar Point cloud las files, which contains only one type of feature (such as electrical transformers, with no background features). I want to use those hundreds of transformer Poincloud datasets in las format, for creating training datasets for doing ML Lidar classification. How can I create labels for those hundres of pointcloud data in MATLAB?
Thanks Ray
Hi everyone,
I need assistance with a task related to combining two TLC (Target Language Compiler) files for model compilation. I have two TLC files, 'ert.tlc' and 'cnp.tlc,' which are essential for generating code from my Simulink model.
I would like to create a single 'combined.tlc' file that allows me to compile the model using both 'ert.tlc' and 'cnp.tlc.' However, I am facing some challenges in merging these files effectively.
I'm looking for guidance on how to:
- Combine 'ert.tlc' and 'cnp.tlc' into a single 'combined.tlc' file.
- Ensure that 'combined.tlc' appears in the Model Settings under the 'CodeGeneration' parameter.
This is important for me because my model is including some function blocks which is only supported to compile by cnp.tlc but also I have complie my model with ert.tlc because I want generate my model to ASAP2(.a2l).
Thanks for helping!
Share your fun photos in the comments!
Hi guys, I've still can't figured it out the element behind the current and voltage measurement, does anyone know what element is this? Really appreciate for the answers. It will be very helpful for my fyp project.
hello,im student and my project is about creating a drive for ev using synchronous reluctance motor. for that i need one circuit in which i can check different parameters like speed, torque,etc. of different motors. i need one reference drive circuit in which i can replace motors and check their performance. hoping for help thank you :)
Hi all,
I want to solve an ode45 equation for a multibody model. The matrixes I have to implement in the ode45 are very big. Now I am using the subs function to place the values for x into the matrixes. However because the fact that this is done inside the ode45 function running the function takes a while. Is there a way to already implement the x value in the matrixes as a variable outside the ode45 function?
In the code WT and w_bar are matrixes of 12x15 and12x1
The vector hulp_vec and hulp_vec_derivative contain both 15 syms variables
% Solve the equation
[t,x]=ode45(@(t,x)analytical_simplified(t,x,M,H,S,WT,w_bar,N,constr_eq,hulp_vec,hulp_vec_derivative),tspan,x0);
function [dx, lambda, constraint_eq]=analytical_simplified(t,x,M,H,S,WT,w_bar,N,constraint_eq,hulp_vec,hulp_vec_derivative)
tic
tau=[0;sin(t);0];
%make matrices afhankelijk van x and dx
% WT=subs(WT,hulp_vec',x(1:N));
WT=subs(WT,hulp_vec_derivative',x(N+1:2*N));
w_bar=subs(w_bar,hulp_vec',x(1:N));
w_bar=subs(w_bar,hulp_vec_derivative',x(N+1:2*N));
constraint_eq=subs(constraint_eq,hulp_vec',x(1:N));
toc
tic
Minv=inv(M);
% Stabilize the matrixes
wo=100;
alpha=wo/5; beta=1;
w_bar_stab = w_bar + 2*alpha*beta*WT*x(N+1:2*N) + alpha^2*constraint_eq;
% w_bar_stab=w_bar;
L1=(WT*Minv*WT');
L2=(WT*Minv*(H-S*tau)-w_bar_stab);
L1=double(L1); L2=double(L2);
lambda=L1\L2;
ddx=Minv*(S*tau-H+WT'*lambda);
dx(1:N)=x(N+1:2*N);
dx(N+1:2*N)=ddx;
dx=dx';
dx=double(dx);
toc
end
With kind regards,
Janne
Good day community, can I know what is this symbol could be? It looks like a ramp/ continuous ramp. But I believe it is not both them. I saw someone connect it after a voltage/ current measurement. Can I know what is the function of this symbol too? Much appreciate for the answers given
Hello All,
I was wondering, from which version Tracebility Diagrams are available (in SLK Req)?
Regards
Abhishek KUMAR
Hello, I am trying to use a Velodyne VLP 16 Puck Lidar, to receive live data (visualized) as well as point cloud, the issue I have is; I do actually run the code to visualize the lidar and I can see the live map, as well as I get frames in the work space as (1x1 Pointcloud), now how can I process these pointclouds(from the live stream of lidar), I would like to denoise them, downsample, etc. I tried going through alot of toolboxes but I usually get stuck, need tips and how to start working, thanks.,
unable to download and cant install Arduino third party packages , but support packeages are download, 
- Why do the stations transmit to each other while there is no association among them?
- How the stations transmit to the access point while the traffic generation is one way?
please find the attached code"ex1_AP_STA.m" and output data of simulator "Simulation data.zip"
when i use command openExample('px4/PX4HITLSimulationFixedWingPlantSimulinkExample')，matlab shows "PX4HITLSimulationFixedWingPlantSimulinkExample" cannot find. So does somebody know how to find this demo? Thanks.
ncorr is not working on MATLAB 2023b new version, it gives me an error. Does somebody know why? Thanks
I know the latest version of MATLAB R2023b has this feature already, put it should be added to R2023a as well because of its simplicity and convenience.
Basically, I want to make a bar graph that lets me name each column in a basic bar graph:
y=[100 99 100 200 200 300 500 800 1000];
x=["0-4" "5-17" "18-29" "30-39" "40-49" "50-64" "65-74" "75-84" "85+"];
bar(x,y)
However, in R2023a, this isn't a feature. I think it should be added because it helps to present data and ideas more clearly and professionally, which is the purpose of a graph to begin with.
Dear all,
In an excel file, we have temperature (te) and humidity (hu) data in two columns. The Gaussian kernel-density estimation and best-fit quadratic curve were plotted. However, we need to determine whether the relationship is statistically significant or not, as well as the coefficient of determination (R2). For calulation of the both of them, we used functions like:
2. statistically significant p= coefTest(aa)
Is it correct? If not, please provide the any other suggestions.
Thank you.
For example, my main line chart have values: X=[10 20 30 40 50] Y=[0.5 1.5 5 -6 4]. I need to add second X axis, with value [1 2 3 4 5] but but I would like the distance between individual points to be variable. For example, between points 1-2 d=25, between 2-3 d=10. I would like to define this distance freely.
xt = e^-3t
ht= -5e^-2t +6e^-3t
so ofcourse these would be used to plot yt which is xt*ht in other words xt conv ht. Thanks for your assistance!!
Recently, I came across a post about the JIT compiler on this Korean blog. In the post. The writer discussed the concept of the "Compile Threshold" and how it is calculated.
"The JVM accumulates the number of calls for each method called and compiles when the number exceeds a certain number. In other words, there is a standard for checking how often it is called and then deciding, 'It is time to compile.' This standard is called the compilation threshold. But what is this and why should it be used as a standard?"
The concept of the "Compile Threshold," as used above, seems to be more commonly associated with Tracing just-in-time compilation.
The writer used the simple Java code below to calculate the threshold.
for (int i = 0; i < 500; ++i) {
long startTime = System.nanoTime();
for (int j = 0; j < 1000; ++j) {
new Object();
}
long endTime = System.nanoTime();
System.out.printf("%d\t%d\n", i, endTime - startTime);
}
Since the MATLAB execution engine uses JIT compilation, I just wanted to perform the same experiment that the writer did.
I experimented using simple codes based on the code in the blog. I iterated a function 500 time using for-loop and calculated the execution time for each iteration using tic and toc. Then I plotted the execution time for each loop as blow. First five execution times are much higher than followings (10 times!) The test is very rough so I am not sure that I can conclude "MATLAB has Compile Threshold and it is 5!" but this value is actually correct ;-)
t0 = 0;
tfinal = 10;
y0 = [20;20];
timeToRun = zeros(500,1);
for i = 1:500
tStart = tic;
[preypeaks,predatorpeaks] = solvelotka(t0, tfinal, y0);
tEnd = toc(tStart);
timeToRun(i) = tEnd;
end
