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Star Strider


11,459 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
The following error occurred converting from sym to double: DOUBLE cannot convert the input expression into a double array.
To define a vector of subscripts to ‘lb’, use square brackets, just as you woukld with any other array: syms a b c d e f g h ...

5 hours ago | 0

Answered
Modifying elements in a list
You do not need the loop. Just do this: timestr = ["758" "808" "828" "838" "848" "858" "908"] timenum = str2double(timestr...

6 hours ago | 0

Answered
How can I do a datetime vector?
Just do something like this: T = datetime('03/19/2019 16:36:41') H = datetime(T,'Format','HH:mm:ss') producing: T = da...

9 hours ago | 0

Answered
moving average of array
If you have R2016a or later, use the movmean (link) function. Otherwise, see the filter (link) documentation section on Movin...

10 hours ago | 0

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Answered
Spline to optimize the curve
Try this: A = [ 2.0000 2.0000 2.2703 1.6902 4.7244 7.6318 12.0984 9.1030 12.0000 10....

11 hours ago | 0

Answered
How to plot the derivative from experimental data
Not a specific MATLAB function, but it’s easy: dydx = diff(y(:))./diff(x(:)); If you want dydx to be the same length as x and ...

1 day ago | 6

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Answered
How to calculate approximation error from 1x1 and 1x1001 symbolic signals
Much depends opn how you defined your triangularPulse. One option: syms x T(x) T(x) = triangularPulse(x); Tfcn = matla...

1 day ago | 0

Answered
How to draw a perpendicular line using a point and slope
Try this: P1=[374 448]; P2=[385 562]; P12 = [P1;P2]; mP12 = mean(P12); b = [P12(:,1) ones(2,1)] \ P12(:,2); ...

1 day ago | 0

Answered
Extract values from ODE45
‘How Do I extract the values of Ra and Rb and plot them ?’ You don’t ‘extract’ them. Just recalculate them from the integrat...

2 days ago | 1

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Answered
How to draw a electromagnetic wave and plot it in 3D
I’m not certain what you want. Try this: E = 2; H = 3; t = linspace(0, 2*pi); omega = 2; k = pi/2; x = ones(size(t))...

2 days ago | 0

Answered
matrix of dimension 100,000 x 100,000 x 100,000
You do not need a technician. You need at least 8 petabytes ( bytes) of memory for your matrix alone (double precision). Goo...

2 days ago | 0

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Answered
Black axes for yyaxis (not default blue and orange)
Try this: figure yyaxis left plot((1:10), rand(1, 10), 'g') yyaxis right plot((5:15), sin((5:15)/5), 'r') ax = gca; ax.Y...

2 days ago | 0

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Answered
how to get 2 outputs of my function?
The reason is likely the way you are calling your ‘LR’ funciton. If you request both outputs, your function will deliver them...

2 days ago | 1

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Answered
How do I make a menu save the choice as a string instead of a value?
Address your ‘D’ cell array with the ‘day’ variable: % Create array for days of the week: D={'Monday','Wednesday','Friday'}; ...

2 days ago | 0

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Answered
Plotting function in two variables only for specified domain
Logical matrices can result in vector results that can be difficult to work with for surf, mesh, and similar plots that require ...

2 days ago | 0

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Answered
WHY DATE CANNOT TRANSFER FROM EXCEL TO MATLAB BY XLSREAD?
If you have R2013b or later, use the readtable (link) function. It should automatically convert the Excel dates to MATLAB dates...

2 days ago | 1

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Answered
2d truss analysis
You don’t have negative integers, however positive integers are integers greater than 0. Here: SN = MemberP(j,1); ...

2 days ago | 0

Answered
Error using ^ Incorrect dimensions for raising a matrix to a power when trying to simulate a steady state simulation of DFIG
I’m not certain what you want, or what your code does. One option is to address only the latest elements of the vectors (even...

2 days ago | 0

Answered
How do I plot a certain interval?
This will overplot the region (8,12) with a red dashed line: for N = 8; Mc = [-2:0.01:15]*N; Pi_c = 1+(2*N-1)*(3-2*M...

3 days ago | 0

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Answered
How do I adjust my histogram to show approx. 50 different categorized bins with very small data?
You need to subscript ‘t’ to save it as a vector. Try this: iter=10000; FS=40; for n=1:iter Sy=2.11*10^8+(60*rand(1)...

3 days ago | 0

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Answered
Using the 'Surf' command for variable 'x' values
It doesn’t work because ‘y’ is a vector. Try this: x= [1.158633 4.871195 7.667851 11.45038 22.11895 1.221922 3.77...

3 days ago | 0

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Answered
Adding standard error bars to grouped bar graph
You are in luck in not using categorical variables, because this approach will not work with them (although I’ve not had the opp...

3 days ago | 0

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Answered
Need to combine every other column of two row vectors of different sizes in MATLAB
One approach: A = [1 3 5 7 9 11 13 15 17]; B = [2 4 6 8 10 12]; C(1:2:numel(A)*2) = A; C(2:2:numel(B)*2) = B; C = C(1:mi...

3 days ago | 1

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Answered
How do I multiply a column in a matrix by a range of values?
I am not at all certain what result you want. Try these: spark_rng = linspace(-12, 30, numel(sfd(:,3))); ...

4 days ago | 0

Answered
How to order variables by their size?
Try this: [~,ix] = sort(cellfun(@sum, onsets)); Out = names(ix) producing: Out = 1×3 cell array {["C"]} {["...

4 days ago | 1

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Answered
how to extract pcg signal features from a dataset for machine learning
See Wavelet Time Scattering Classification of Phonocardiogram Data (link).

4 days ago | 0

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Answered
low pass filter to matrix
You can apply any filter to a matrix using the filtfilt (link) function to do the actual filtering. From the documentation: ...

4 days ago | 0

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Answered
How to locate last peak in data?
Use the findpeaks (link) function, most likely with the 'MinPeakHeight' name-value pair. Then use the second ‘locs’ output (an ...

4 days ago | 0

Answered
3D spectrum plot with massive data sets
The spectrogram (link) function will likely do what you want.

4 days ago | 1

Answered
Sample a continuous signal with Sampling frequency
‘Would I do this by only looking at the points of the signal that correspond to the sampling frequency I decide on?’ Yes. In...

4 days ago | 1

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