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# Star Strider

12.275 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.

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find the element location
You have encountered ‘floating-point approximation error’. Most numbers are not exactly represented in floating-point precision...

alrededor de 5 horas ago | 0

importing excel data using for loop
This variation on your loop will generate the names that you can then use for your readtable calls: for kk=1:24 fv = sp...

alrededor de 7 horas ago | 0

how can i plot ?
Try this: A=[2.8866 2.5708 2.9381 2.6234 2.7873 2.8535 3.5818 4.1817 3.6535 4.6312 4.2028 4.4...

alrededor de 13 horas ago | 0

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Plotting FRF with imaginary and real numbers
‘I would like to know if it is possible to plot the graphic of it (resulting in the natural frequencies and stuff) only having t...

alrededor de 14 horas ago | 0

parameter estimation for a set of differential equations using fmincon function in matlab
You will likely find Monod kinetics and curve fitting helpful. (There are similar posts as well.) One way to force ‘dcdt’ to...

1 día ago | 0

How to integrate a set of coupled ODE's?
Your system is ‘stiff’, so use one of the stiff solvers instead of ode45: [t,y] = ode15s(@rate_eq,tspan,y0); With this chang...

1 día ago | 0

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there are more than 1 element satisfy the command in one column, but I only need to count it one time
Try this: maxTemp = max(data(:,4:end),[],2); Above41 = nnz(maxTemp > 41) producing: Above41 = 3

1 día ago | 0

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matlab returns different result for same inputs
You may believe that the value of ‘x’ and the value of ‘x’ that are displayed are the same. They are likely much different, sin...

1 día ago | 1

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find slope sign change of emg signal
Use the gradient function to produce results that are the same sizes as your data, not diff. If ‘EMG’ is your (30000x4) signa...

1 día ago | 0

When do you detrend data or remove the mean?
Both detrending and removing the mean are essentially removing low-frequency baseline variations or a constant offset, respectiv...

2 días ago | 0

how to plot step graph
I am not certain what a ‘step graph’ refers to. Try this: figure stairs(W, X, 'LineWidth',2) grid

2 días ago | 0

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How to fit differential equations to a curve
I would normally suggest that you see Monod kinetics and curve fitting and others. However this is actually a linear problem, s...

2 días ago | 0

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how to fix invalid first data argument
Your code runs without error for me. Note that in your code ‘ii’ is never going to be less than 0, so the entire if block is ...

2 días ago | 0

Cannot load default file for CWT
If you listed the entire result from running the ver function, it seems that you do not have the Wavelet Toolbox.

3 días ago | 0

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I have multiple equations that depend on a specific value and would like matlab to ask the user which equation to use and what the specific value is and then print that value but it's giving me trouble.
The 's' indicates that input for ‘lambda’ should return a character vector, so it does. If the materials are numbered, so the...

3 días ago | 0

4D matrix manipulation
I am not certain what you want. Try this: G = rand(365,31,24,91); % Create ‘G’ Gnew = reshape(...

4 días ago | 0

convert cell to integer
If ‘kar’ is initially: kar = {{[3]}}; try this: n = cell2mat(kar{:}) producing: n = 3

4 días ago | 0

Uncertainty for regressed parameters using nlinfit considering the uncertainty of data
If you want to calculate the confidence intervals on the parameters, use the nlparci function. If you want to calculate the con...

4 días ago | 0

Regression on multi-variable data
This is a linear problem, so a linear solution will work. Try this: M = [1.48 1 0.9 0.69 0]; x = [8.526 5.6 6.9654 7 0]; ...

4 días ago | 0

How can I include a superscript in my x-label
The easiest approach is likely to use semilogx (or if appropriate, loglog) to plot your data. EDIT — I am not sure what tic...

4 días ago | 0

Error showing "Undefined function 'vecline' for input arguments of type 'sym'."
You misspelled it in your call to it. You defined it as: function vectline(f,crdaxis,crdrange,step) however you called it ...

4 días ago | 1

How do I convert a .wav file to a .matlab file using wavread?
The wavread function was deprecated a while ago. Use the audioread function (R2012b and later versions) instead.

4 días ago | 0

How do I convert a .wav file to a .matlab file using wavread?
The wavread function was deprecated a while ago. Use the audioread function (R2012b and later versions) instead.

4 días ago | 0

How to plot below function f
This is how I would do it: f = @(x) (x/4).*((x > 0) & (x < 1)) + (x/3).*(x >= 1); t = linspace(-5, 5); figure plot(t, f(t...

4 días ago | 0

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Contourf plot of datasets
You might find the griddata function useful. It takes random (x,y) values and interpolates gridded z-matrices from them that co...

4 días ago | 1

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Phase spectrum without knowing frequency
The lower trace appears to be the negative derivative of the upper trace. So integrating the negative of the lower trace and ...

5 días ago | 0

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How to detect a column which gives me maximum value of the result.
Try this: x = rand(15); % Create Matrix y = rand(15,1); % C...

5 días ago | 1

Error using xlsread (line 257) Excel Worksheet could not be activated
The problem does not appear to be the Excel file, if you can read it correctly in R2017a. See if using the readmatrix function ...

5 días ago | 0

How do I convert a string to a date?
I am not certain if the numbers are themselves strings, or numbers. If they are numbers, this works: numdate = [20030930230...

5 días ago | 0

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