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Star Strider


Last seen: 1 día ago Active 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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Answered
Issue solving a non-linear differential equation in Matlab
‘Am I wrong?’ No. The result is not always as simple as it might be. In R2021a, the Symbolic Math Toolbox apparently simp...

alrededor de 12 horas ago | 0

Answered
isosurface with wall thickness
There does not appear to be any way to change the thickness of the plotted surface. The best I can come up with is the revise...

alrededor de 12 horas ago | 0

Answered
How can I plot integral of this equation?
Try something like this — % clc; figure('color','white'); while(1) sigma.phi=input('Enter 0.1 in a.u.: '); mu=input('Enter...

alrededor de 16 horas ago | 0

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Answered
How to get the coefficients of a fractional polynomial from syms?
It is not a polynomial, so it is necessary to create it as one and then extract them. syms x, F=29.0*x*(5.7e-4*x + (5.58e-4*...

1 día ago | 1

Answered
How to find and chart the frequency of a letter in column with histogram.
Perhaps — Col = {'HFHFHSHHAJHJA'; 'HSAJHFGFSAGJ'; 'HSGHSFFJHJ'}; T = cell2table(Col) RowSum = cellfun(@(x)sum(x=='H',2),T{:,...

1 día ago | 0

Answered
Error with find(X) statement
Taking a wild guess, since the test is: states=find(sum(UNITARY_MATRIX)~=1.0) it is likely encountering floating-point approx...

1 día ago | 0

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Answered
vector gives 0 integral
There quite definitely is! In your call to it: sd = trapz((z),0,20) the function interprets ‘z’ (the parentheses aren’t n...

1 día ago | 0

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Answered
How to shade/color overlapped area in the graph?
I honestly have no desire to download ‘plotxx’ and learn its intricacies, so I used yyaxis instead here. The same approach sh...

1 día ago | 2

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Answered
Create line between plot points
Yes. x = [0 10 20 30]; y = [355 433 510 590]; figure plot(x, y, '*-r') grid Ax = gca; Ax.XMinorGrid = 'on'; Ax.YMino...

2 días ago | 0

Answered
plotting a phase plane with a system of linear diff equations.
Using the numeric ODE solvers, likely the easiest way to do that is to use odeset to set options, and then choose 'OutputFcn', @...

2 días ago | 0

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Answered
Why am I getting a Parse error for a sequence?
It’s missing an equal (=) sign: for it = 1:MaxIt %this starts 'for' loop and runs for MaxIt times. .

2 días ago | 0

Answered
Is there any way to do LFIT (general linear least-squares fit ) on the time series data using MATLAB?
That depends entirely on what you want to do. One approach: syms a b c d e f g t y = a + b*t + c*t^2 + d*sin(2*pi*t) + e*...

3 días ago | 0

Answered
Problem with reshape and Surf plot
The only solution I can propose is to use either griddata or scatteredInterpolant . Try this — opts = detectImportOptions('...

3 días ago | 0

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Answered
how to sort table by row sub-string values?
Try this — wellname = {'01A58' rand; '01A59' rand; '01A62' rand; '01A63' rand; '01A66' rand; '01A58' rand; '01A59' rand} well...

3 días ago | 0

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Answered
How to filter first fixation times for participants
I had no problems getting readtable to work correctly. I have no ides what the third loop here does, however it now works by ...

4 días ago | 0

Answered
What is the frequency of my signal?
Try this — LD = load('Frequency.mat'); t = LD.t; CH0 = LD.CH0; Fs = 0.1; ...

4 días ago | 1

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Answered
how to do average over third dimension?
Taking a slightly shorter example, try something like this — % ucom = randi(9,21,41,24); ucom = randi(9, 3, 4, 24); sz_ucom ...

4 días ago | 0

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Answered
How to pre-allocate my loop for speed?
I am not certain what the problem is, however the preallocation would be straightforward: pk_seagrass = NaN(1,length(ping_time...

4 días ago | 1

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Answered
Find energy for each second of audio file
Use the buffer function: Fs = 44.1E+3; % Sampling Frequency s = randn(Fs*5.2,1); ...

4 días ago | 0

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Answered
Does anyone know why the second plot doesn't work?
Yes! In line #44, there is a hold off call, although no new figure call, so the subsequent plot overplots the existing plo...

4 días ago | 0

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Answered
function interpolation and root finding
Try this — points = [0.500000000000000 0.500000000000000 0.498097349045873 0.494452298903742 0.49...

5 días ago | 1

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Answered
Please someone help test run this Matlab code and debug it if possible. Please help a student
The ‘uexact’ variable does not exist, and there is nothing similar to it (for example by a different spelling, at least that I c...

6 días ago | 0

Answered
How to solve damped forced vibration analysis using ode45 ?
One problem is with the ‘dxdt’ assignment. MATLAB interprets the spaces as delimiters, so the second row has 3 columns, as MATL...

6 días ago | 0

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Answered
Does anyone know how to add the legend?
I am not exactly sure what you want. First, the clear all and close all calls are not necessary and make your code less effic...

6 días ago | 0

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Answered
Write a complex number in polar form
The ‘image below’ is slightly difficult to read, however the code to do that is easy to write. This is called phasor notation. ...

7 días ago | 0

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Answered
How To Extract Data from Multiple CSV Files and Run Analysis?
Try something like this — T1 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/693589/data1.csv') T...

7 días ago | 0

Answered
How can I plot a trendline that follows the peaks a time-history data set (accelerogram)?
The envelope function could do what you want. Another option is findpeaks, with the appropriate name-value pair arguments. ...

8 días ago | 0

Answered
Detect signal clipping and remove
Without an example signal, I am guessing that the ‘clipped’ or ‘railed’ parts of the sound would be equal to ±1, with the valid ...

8 días ago | 0

Answered
How to calculate the standard error estimation when using fit from curve fitting toolbox?
Yes. Use the predint function. x = linspace(0, 100, 100); y = -0.3*x + 2*randn(1,100); [f,gof,out] = fit(x(:), y(:), ...

8 días ago | 0

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Answered
Create a graph from 2 vectors and a matrix
I would use surf or mesh: figure surf(X,Y,Z.', 'EdgeColor','none') to see it from the top, add: view(0,90) ,

8 días ago | 0

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