Community Profile

photo

J. Alex Lee


Last seen: Today
129 total contributions since 2016

J. Alex Lee's Badges

  • 6 Month Streak
  • Revival Level 1
  • Knowledgeable Level 3
  • First Review
  • Solver
  • Thankful Level 1
  • First Answer

View details...

Contributions in
View by

Answered
Remove tick marks for axes
An easy way to "fake" this after setting "Box" to "off", as Peng Li suggests, is to make xline and yline. But it wouldn't be dyn...

1 day ago | 0

| accepted

Answered
How to find the gradient of a parameter which is not direct solution of a function
Determining l1 for a "target Gam4" value appears not to be an optimization problem, but another root-finding problem. It seems t...

3 days ago | 0

Answered
How to use ode15s with a constant that varies by two parameters?
From you description, it sounds like you want to do the average over d-values outside of our ODE solution. But in your code, you...

3 days ago | 0

Answered
How do I go about plotting points from ODE45 with this?
yes, your odefun looks wrong, it looks like you did not correctly apply matrix algebra to get the separate equations from your m...

3 days ago | 0

Answered
How can I use fmincon to solve problems with ODEs
I presume you mean to use r at some specific time, where r(0) (or some other time) is known - a standard 1D ODE. with some in...

4 days ago | 0

Answered
How to get the solution to a GIVEN input VECTOR using ode45 solver
If you're just looking for code to extract some element out of your ode45 solution: tAll = nan(1,length(u_opt)); xAll = nan(4,...

6 days ago | 0

| accepted

Answered
Separating and extracting data using edge detection
since it appears you have the image processing toolbox (access to "edge"), have you looked into "regionprops"? If you're label...

6 days ago | 0

| accepted

Answered
Solution to 2nd order ode containing time varying coeficients using ode45
can you use the code editor functionality to display code? Multiple issues: you don't need to "run" the gglpr9 function...is t...

6 days ago | 0

Answered
How to amend the names of all variables in all tables in the current workspace
You can still "bandaid" your situation up by reading the named tables in your workspace into the cell array that could have been...

7 days ago | 1

Answered
Parallelized ODE45 solution with 3D spline
Can you just pass the variables spx spy spz to func_xy as additional arguments? q=1.6e-19; m=400*1.6e-27; odeOpts = odeset(...

7 days ago | 0

| accepted

Answered
Given a point, locate 3 point in different 8 directions.
Or since there is a built-in called improfile (with one toolbox or another), you can skip the convolutions for gradients, take t...

7 days ago | 0

Answered
Given a point, locate 3 point in different 8 directions.
as long as we're guessing at the problem, an approach that would alleviate the need for line scans would be to rotate the source...

7 days ago | 0

Answered
Flipping the axis starting value of a plot in matlab
Does this do what you want figure(i); dscatter(X,Y); colorbar; hold on set(gca,'YDir','reverse') % <- added this line

8 days ago | 0

| accepted

Answered
time dependent constant to solve 1st order ODE via ode45
Seems like you just need Tw to be a function of T (of var(1)). function diffeqs= ode_sys(t,var) T=var(1); ...

11 days ago | 0

| accepted

Answered
How to dynamically define limits forplot from user input in app designer?
Do not use a loop. Use the edit boxes, and use their callback functions to set the axis limits. It sounds like you should take ...

12 days ago | 0

Answered
How to remove all background noise due to inappropraite lighting from my pre-processed image and get better edge defination??
try smoothing before you apply your edge detector, not after same goes for your power law (gamma correction?) alternatively/al...

14 days ago | 0

| accepted

Answered
Paste Data to Editable Table in AppDesigner UI
when you say you don't want to use xlsread, is it that you don't want to force usage of excel, or you don't want to read files a...

14 days ago | 0

Answered
How to binary clone a file using fread and fwrite commands
For your application does it make sense to just copy the file using a system command or matlab's coyfile?

16 days ago | 1

Answered
Newton-Raphson Method with Jacobian
In Newton loops you must evaluate your f and j and currently guessed iterate, so your line h = -f(x0(1),x0(2),x0(3))*j(x0(1),x0...

18 days ago | 0

| accepted

Answered
Solving Linear Differential Equations for Path Following ; I am getting difficulties in implementing the coding with variable psi_e, let's say if I want to run it for psi_e going from 0 to pi/2, how can it be done?
To change value of psi_e (make it variable) seems straightforward: make psi_e an input in your odefun, then loop over psi_e: f...

18 days ago | 0

Answered
how to use tensors
this is a bit imprecise, but if you mean "order 2 tensor", it can be represented as a 2D matrix. Order 3 tensor is then 3D matri...

24 days ago | 0

Answered
ode45 error rungg- kutta
your error is probably not with the ODE line, but actually running "Simulation", which you are not supplying any arguments to at...

1 month ago | 0

Answered
Solving second order PDE
Does this help: https://www.mathworks.com/help/matlab/ref/pdepe.html I believe that pdepe is available with base matlab. It ap...

1 month ago | 0

Answered
Saving multiple outputs from ODE45 with different dimensions?
I would use cells...also what's with the dual indexing? options can be defined outside since nothing is changing from iteration ...

2 months ago | 0

Answered
Increment a class property everytime calling a class method
subclass from the handle class (default is value class), and you can update properties of the instance without explicitly overwr...

2 months ago | 1

| accepted

Answered
How to plot values with different color with "if statement"
look at the documentation for the "scatter()" command. can you do what you want with that?

2 months ago | 0

Answered
App inside app question
If not more than 1 image needs to be displayed at once, maybe just save all the image data internally, have only one axes, and h...

2 months ago | 1

| accepted

Answered
Selection of data in timetable
Hmm, so the question is about periodic time ranges...there might be a better way, but maybe you can use "isbetween" on an auxili...

2 months ago | 0

Answered
How can i select cell from table in app designer?
The UITable has a callback for selection https://www.mathworks.com/help/matlab/ref/matlab.ui.control.tableappd-properties.html#...

2 months ago | 0

Answered
Reading data from ASCII file
It would have been helpful to know these things in advance (you hinted at the first, but say it explicitly) Data contains multi...

3 months ago | 0

Load more