結果:
Seeing a colleague make this mistake (one I've had to fix multiple times in other's work too) makes me want to ask the community: would you like the awgn() function/blocks to give the option for creating a SNR at the bandwidth of the signal? Your typical flow is something like this:
- Create a signal, usually at some nominal upsampling factor (e.g., 4) such that it's now nicely over sampled, especially if you're using a RRC or similar pulse shaping filter.
- Potentially add a frequency offset (which might make the sample frequency even higher)
- Add AWGN channel model for a desired SNR
- Put this into your detector/receiver model
The problem is, when someone says, "I'm detecting XYZ at foo SNR," it should not magically improve as a function of the oversample. The problem isn't that awgn() generates white noise, that's what it's supposed to do and the typical receiver has noise across the entire band. The problem is that SNR is most properly defined as the signal power over the noise power spectral density times the signal's noise equivalent bandwidth. Now I looked and there's no handy function for computing NEBW for an input signal (there's just a function for assessing analysis windows). In practice it can get a bit tricky. The occupied bandwidth or HPBW are often close enough to the NEBW, we're usually not haggling over hundredths of a dB. So, in my not so humble opinion, the "measured" flag for awgn() should give an option for bandwidth matching or at least document the behavior better in the help page. All too often I'm seeing 3-6 (or worse) dB errors because people aren't taking the signal's bandwidth into account.
Unlike last year's contest, there are some new technologies this year that might offer some advantages. Namely generative AI's like ChatGPT, Bard, etc. Not to be excluded, MathWorks just launched the AI Chat Playground :)
i need to create an app in app designer that is able to convert ac to dc. i already created the layout of the app and i created a curcuit that is able to convert ac to dc in sumilink. but i am having troubles linking the circuit simulation to the app.
Basically, i want the user to input the voltage in the app and it should send that data to the simulation and the output should come back to the app.
I want to use "phased" fuction to generate pedestrain dataset, but I don't know how to generate multi-path.
Hi
I connected raspberry pi with MATLAB. But when I deployed the function, I kept reminding me that the function was not found. But my function does exist and can be implemented
Can you tell me why and how to solve it?
Many thanks,
Bang
When I apply genetic algorithm to find the optimal parameter, before the parameter enters the algorithm, I have controlled the parameter to keep two decimals in their respective ranges, but when the final output, the optimal parameter returned is really six decimals. Why? What am I supposed to do? (Note: I need to keep two decimal places in the parameter before entering the algorithm, because a change of 0.001 in the parameter has a great effect on the result, so I can't round the result directly.)Look forward to your reply~
good afternoon everyone my name is Dundu lawan haruna ,i'm a final year student at the department of computer engineering ABU Zaria, Nigerian , and i wanted to do my final year project based on computer vision : project topic , designing an eye glasses to help those people with visual imparement to be able to navigate enviroment efficiently , that's why i need a support from you guys ,all advised are highly well come , thank you for your support.
Participants across all skill levels are welcome to join! You can participate by creating a new animation or remixing an existing one with up to 2,000 characters of MATLAB code.
Contest Tips:
- Before you start, we highly recommend you check out the two examples - Bouncing and Spinning - to understand how the contest works.
- Share your thoughts, ask questions, or connect with others in our contest discussion channel.
Note that the first week (Nov. 6th, 2023, ~ Nov. 12th, 2023) is for creating entries only. Voting does not begin until the second week.
We look forward to seeing your creative work. Let the contest begin!
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.,
