Community Profile

photo

Star Strider


Last seen: Today
15 323 total contributions since 2012

Hic sunt dracones!

PROFESSIONAL: Physician (M.D.): Diplomate of the American Board of Internal Medicine; M.Sc. Biomedical Engineering: Instrumentation, Signal Processing, Control, System Identification, Parameter Estimation

NON-PROFESSIONAL: Amateur Extra Class Amateur Radio Operator; Private Pilot, Airplane Single Engine Land, Instrument Rating Airplane; Gamer

NOTE: I do not respond to emails or personal messages, unless they are about my File Exchange contributions.

Contact

Star Strider's Badges

  • Personal Best Downloads Level 2
  • 5-Star Galaxy Level 3
  • First Submission
  • Grand Master
  • 36 Month Streak
  • Thankful Level 3
  • Revival Level 2
  • Knowledgeable Level 4
  • First Answer
  • Scavenger Finisher
  • Solver

View details...

Contributions in
View by

Answered
Coupled rate ODEs with ode45
The concentrations change appropriately, however they don’t change much and the concentrations are vanishingly small. That’s th...

environ 2 heures ago | 0

Answered
Figure line won't connect/display all data points
Isolated points only plot if specified as markers. Try this: D1 = load('midpoint.mat'); midpoint = D1.midpoint_overlap_seq...

environ 3 heures ago | 0

| accepted

Answered
How to solve this equation?
Probably the easiest approach: syms h z2 Eqn = h^0.66+0.0805*h == 0.045; [h,prms,cndx] = solve(Eqn,h, 'ReturnConditions',1)...

environ 5 heures ago | 0

Answered
ode45: use span of length 2
The tspan argument can be anything you want it to be (within limits). To have ode45 to evaluate and output at only those valu...

environ 6 heures ago | 0

Answered
passing a vector to a function: 'Not enough input arguments'?
With a function in that format, it is necessary to pass a function handle to lsqnonlin (or any other function that takes a funct...

environ 6 heures ago | 0

Answered
How to plot only the real solutions of an implicit function ?
Nothing is being generated: R = 0.35; L = 0.25; H = 0.4; f1 = @(x,y) sqrt(L^2-(R*(cosd(x)-sind(x).*sind(y))-H).^2); figu...

1 jour ago | 1

Answered
Plot and calculate Damping ratio
The findpeaks or islocalmax functions can return the information to do the calculations.

1 jour ago | 1

Answered
Trouble taking the differential of a function
‘What am I missing here?’ Most likely, using the Symbolic Math Toolbox. Try this: syms E I L w_0 x func(x) = (((w_0*L)...

1 jour ago | 0

Answered
Help with Errorbars on Bar Graph
Try this: AngleFlex90 = [95 99; 93.33 80; 95.67 99.33]; AngleError = [8.9 6.6; 7.6 5; 4 1.2].'; figure hBar = bar(Angle...

2 jours ago | 0

| accepted

Answered
Gaussian Fit for x and y data
Try this: D1 = readmatrix('Test1.xls'); x = D1(:,1); y = D1(:,2); gausfcn = @(b,x) b(1).*exp(-(x-b(2)).^2/b(3)); [maxy,i...

2 jours ago | 0

| accepted

Answered
Shade the region between the lines and xy axis
Try this: x=linspace(-2,8); y1=@(x)(8-2*x); y3= @(x)(5+2.5*x); y4=@(x)(0*x); y5=xline(0); y1_xint = fzero(@(x) y1(x), 1);...

2 jours ago | 0

| accepted

Answered
Find index of value in array
It is not obvious to me how the number of subjects and the repitition time interact, however it is unlikely that a loop is neces...

2 jours ago | 0

| accepted

Answered
what is the reason of an empty diagram?
It is likely necessary to index the variables appropriately. Try this: xdot10=-(1/m_c)*(k_ss*(x(:,9)-x(:,5)+r*x(:,7))+c_ss*...

2 jours ago | 0

| accepted

Answered
Need help solving a system of 2 second-order differential equations using ode45
I am not certain what you want. This assignment: thetaVec = deval(thetaVals,tVec,1); returns the value of ‘theta’ for the ...

2 jours ago | 0

Answered
how to solve 2nd order coupled system of differential equations with heaviside function using ode45 solver?
Numerical ODE solvers do not do well across non-differentiable discontinuities. The heaviside function in MATLAB is differentia...

2 jours ago | 0

Answered
Convert Excel to Timetable
‘I attached the excel sheet as well ...’ Not yet. The readtimetable function may be appropriate if you have R2019a or la...

3 jours ago | 0

Answered
set the vector same length
The approach depends on what you want as the result: x = [2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016]; ...

3 jours ago | 0

Answered
How to get the first value in a set of array that is bigger than the first few values?
Try this: y = [1 1 1 1 1 1.5 1.7 1.9 2 2.7]; x = [25:35]; TF = ischange(y,'variance'); Idx = find(TF,1,'first') Out = x(...

4 jours ago | 0

| accepted

Answered
Combining repetitive curves into one average curve
One option is to do something similar to the approach in How do I find and plot the average of action potentials from a trace? ...

4 jours ago | 1

| accepted

Answered
Help translating this expression to Matlab
My best guess: y = (exp(3*t) + t.^2.*sin(4*t)).*cos(3*t).^2; or as an anonymous function: y = @(t) (exp(3*t) + t.^2.*sin(4*...

4 jours ago | 0

Answered
How to integrate with distribution function?
That looks like a version of the Lognormal Distribution. It would likely be best to code the ‘M’ result as a function of ‘H’, a...

4 jours ago | 0

Answered
"Invalid interpolation method" after moving to MATLAB2020b
See method in the interp1 documentation (R2020b, however I doubt if it’s changed significantly since R2018b).

4 jours ago | 0

| accepted

Answered
timetable to wav file
I never did anything similar, so this is simply the approach I’d try first. Perhaps first timetable2table then table2array, t...

5 jours ago | 0

| accepted

Answered
How do I find the start and stop indexes of non-zero segments of a matrix?
The ischange function could be helpful. A related Signal Processing Toolbox function is findchangepts.

5 jours ago | 0

Answered
Converting magnitude (dB) and phase (deg) to complex value
Try this: complexVector = [10.^(mag_dB/20) .* exp(1j*deg2rad(phase_degrees))] or as an anonymous function: complexVector = ...

5 jours ago | 1

| accepted

Answered
Different Approach to solve ODE
I have no idea how the ‘Linear Damping Response’ section figures into this. However: syms t x(t) Y Dx = diff(x); ode =...

5 jours ago | 0

| accepted

Answered
Attempting to plot a 3 x 3 grid of plots
Try something like this: time = linspace(0,2*pi); response = @(Kp,Kd) sin(time*Kp) .* cos(time*Kd); Kp = [2.4 180 250]; K...

6 jours ago | 1

Answered
Plotting help with a simple problem
Subscript all of them. Try this: a=750000; %staring amount b=35000; %starting withdrawl y=0; %years while a>b ...

6 jours ago | 1

| accepted

Answered
Finding lowest value and the index from vector excluding zero and inf
Try this: x = [1 3 2;-1 inf 0.5]; [r,index] = min(x(x>0)) producing: r = 0.5 index = 5...

6 jours ago | 0

| accepted

Answered
Way to visualise system of ODEs
Try your code with these changes: [V1,Sbs] = odeToVectorField(ODE1,ODE2); F1 = matlabFunction(V1,'vars',{'t','Y'}); ...

6 jours ago | 0

| accepted

Load more