Star Strider

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15.121 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

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Answered
Please, How do I determine the Mean Absolute Value (MAV) of an acoustic signal, which has positive and negative data points?
The mean value is the ‘average’ value. In almost all audio signals, the mean value is either 0 or close to 0. An electrocar...

circa 9 ore ago | 0

Answered
xlswrite is not recommended, what should I use instead?
Since you have R2020a, first, create a table using your data, then use writetable to write it to an Excel file (or other options...

1 giorno ago | 1

Answered
Hello everyone, how to divide a piece of data into upper and lower parts along the y-axis with C point and D point as the boundary?
Try this: D = load('data1.mat'); data1 = D.data1; x = data1(:, 1); y = data1(:, 2); [C,ixmin] = min(x); [D,ixmax] = max...

1 giorno ago | 1

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Answered
Hodgkin-Huxley Error Code: Index exceeds the number of array elements (1)
Your differential equation returns a column vector of 4 elements, so it is necessary for the initial conditions vector and whate...

1 giorno ago | 0

Answered
contourf plot gives white bands
Without your data, it is not possible to determine with any certainty what the problem is. Two observations: First, [X,...

1 giorno ago | 0

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Value of x for which AUC reaches a given value
‘I calculate the AUC using the trapz function.’ That being the problem. Use cumtrapz instead: t = linspace(0, 1, 500); ...

1 giorno ago | 1

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Answered
How can I solve this equation in which variable is in power
One option is to use GlobalSearch: y = [2.1544; 1.71; 1.99; 1.59]; rhs = @(a,b,c,d) [a*(5.95.^b) + c.*(5.95.^d); a.*(6.72.^b)...

1 giorno ago | 1

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Answered
running MATLAB ode45 back-to-back
‘The first state solution that is returned, is it the same as the initial condition?’ In my experience, yes. Sometimes it is...

2 giorni ago | 1

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Answered
How to flip the data upside down without flipping the axes?
I am not certain what result you want. Try this: x = [1 2 3]; y = [6 13 11]; figure plot(x,max(y)-y+min(y)) .

2 giorni ago | 0

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Answered
Plot contour with 3 variables
The contour function requires matrices. You will need to create the matrices from your vectors. Try this (with your actual d...

2 giorni ago | 1

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Answered
how to apply bandpass filter to a .wav file
Use the bandpass function. For best results, also specify: 'ImpulseResponse','iir'

2 giorni ago | 0

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How to adjust data?
It would be easiest to use the detrend function: t = linspace(0, 100, 1E+4); % Create Data s = sin(2*...

3 giorni ago | 0

Answered
how to set axis with different interval ?
One option is to change the scale of the x-axis: % x y M = [ 3 10 5 11 7 09 10 12...

3 giorni ago | 0

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Answered
How to find period of a signal using fft?
Prototype fft code: t = ...; % Time Vector s = ...; ...

3 giorni ago | 0

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Answered
Record best solution in each GA generation running with UseParallel=true
See: How to save data from Genetic Algorithm in case MATLAB crashes? That will likely do what you want. Define it as the out...

3 giorni ago | 0

Answered
Fitting experimental data to spring damper ODE
You have already referenced two (of the many possibilities I have posted) to estimate the parameters of your system that I would...

3 giorni ago | 0

Answered
How do I find the indices of NaN values in a cell array?
Try this: D = load('XTrain2_all.mat'); XTrain2_all = D.XTrain2_all; hasNaN = cellfun(@nnz,cellfun(@isnan, XTrain2_all, 'Un...

4 giorni ago | 0

Answered
sum in sequence, string, matrix
Try this: M = 1:8760; % Create Vector Mr = reshape(M, 24, []); % Reshape V...

4 giorni ago | 1

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Answered
How to implement a FIR approximation of the analytic signal
I am not certain what you want to do or what the problem is with the hilbert function. If you have calculated the spectrum (u...

4 giorni ago | 0

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Answered
MATLAB stem function error
Either just use ‘z1’, or use a ‘shape’ argument with conv: n = -15:15; u = n>=0; u1 = n>= 4; f = u-u1; z1 = conv(f,f,'same...

4 giorni ago | 0

Answered
Draw shapes not in a graph
Try something like this: x1 = rand(1,5); y1 = rand(1,5); x2 = rand(1,7); y2 = rand(1,7); figure plot(x1, y1, 'or', 'Mar...

4 giorni ago | 0

Answered
please help me (dsolve)
The single quotation marks are likely the problem. Try this slightly edited version: syms y(t) Dy = diff(y); D2y = diff(...

4 giorni ago | 0

Answered
How Do I Fitting a 3 Unknown Parameter Model?
There are several functions available to estimate the parameters. This uses fminsearch because everyone has it: VFTfcn = @(b,...

5 giorni ago | 0

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Answered
Matlab interpolation between two surfaces
Experiment with this: x = linspace(-5, 5, 20); y = x; [X,Y] = ndgrid(x,y); z = @(x,y,s,h,a) a .* exp(s*(x.^2+y.^2)) + h; ...

5 giorni ago | 0

Answered
complementary error function (surf plot)
Add: [X,T] = ndgrid(x,t); and it works: x = linspace(0,10^(-6),20); t = linspace(0,5,5); [X,T] = ndgrid(x,t); u0 = 10^(-...

5 giorni ago | 0

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Answered
Solving equations using Laplace transform
Unless you are solving a partial differential equation, such that the Laplace transform produces an ordinary differential equati...

6 giorni ago | 0

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Answered
Answers editor seems to be broken
The website was updated. I had the same problem, and it turned out that Rena’s suggestion that clearing the Firefox cache solve...

6 giorni ago | 0

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Answered
Error using atan2 Inputs must be real.
If you want to compute the phase angle of a complex number, use the angle function.

6 giorni ago | 0

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Answered
How to get unknown number of variables to be all same length through interpolation
Try this approach: V1 = sort(rand(1,5)); % Original Vector V2 = sort(rand(1,10)...

6 giorni ago | 0

Answered
ode15s error（Genetic algorithm for differential equation parameter identification）
I cannot follow your code. See Ode system solution with unknown constant for one example of an approach that generally works....

6 giorni ago | 0