Star Strider

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15.865 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
How to change X axis in the form of percentage
Try something like this — x = linspace(77, 146); y = -60 - 15*sin(2*pi*x/50); figure plot(x, y) Ax = gca; xt = Ax.XTick...

etwa eine Stunde ago | 1

Answered
How do I allow the user to save all the images of the floorplans they've created?
Perhaps — saveas(gcf, sprintf("floorPlan_%d.png",b) ); will save more of them.

etwa eine Stunde ago | 0

Answered
Plotting a filter as a function of cyclic frequency using freqz()
Your approach is correct. The reason the freqz plot did not look correct is that you were passing the filtered signal to it, no...

etwa 9 Stunden ago | 0

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Answered
Coupled second order differential equation
Start by writing the equations using the Symbolic Math Toolbox. Specifically, see the documentation on the dsolve function. ...

etwa 13 Stunden ago | 0

Answered
ode45 not working
There are a few errors, all easily solved. Try this — m = 5; g = 9.81; r = 0.470; I = 0.37; ks = 0.012; dt = 0.01; ...

etwa 16 Stunden ago | 0

Answered
How to tell matlab that y is a function of x; not a constant
In the initial syms call, declare ‘y(x)’ instead of ‘y’ — syms x y(x) z z=x*y; Dz = diff(z,x) ...

etwa 20 Stunden ago | 1

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Answered
Locating rising peaks of variable amplitude pulses
I am not certain what you are doing, or what the ‘overlaid pulses situation’ means. There appears to be a significant amount ...

etwa 22 Stunden ago | 0

Answered
How do I make a low-pass filter on this data set?
For an EKG, use the bandpass function with the lower cutoff at 1.5 Hz and the upper cutoff between 45 Hz (if there is mains or p...

ein Tag ago | 0

Answered
Adding text to each subplots
Use xlim and ylim to make the text positions relative to the axes — x1 = linspace(0,10, 25); y1 = exp(-0.1*x1); x2 = linspac...

ein Tag ago | 0

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Answered
Error in App Designer " Undefined function 'sym2poly' for input arguments of type 'char'.."
Apart from the app code, apparently the numerator and denominator polynomials are not being transofmred into symbolic variables....

ein Tag ago | 1

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Answered
How to get tfest() to focus on a frequency range (or is something else wrong)?
Without any data or code, and since I have no idea how that was plotted, the only solution I can offer is to use the compare fun...

ein Tag ago | 0

Answered
CIplot unable to fill on log-x axis
I am not certain what you are doing. However in many situations, it is easier to initially plot in a linear scale, then afterwa...

ein Tag ago | 0

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Answered
Numerical integration using Trapz
That should produce one scalar value as ‘F’, so the subscripts are not necessary. I would do something like this — F = trap...

2 Tage ago | 0

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Answered
Data is not importing? SOS
It is not importing because the correct approach to reading .wav files is to use audioread. Try that. It should do what you ...

2 Tage ago | 0

Answered
unable to solve with respect to y
Try this — syms s x y(x) y0 Dy0 C1 C2 Dy = diff(y); D2y = diff(Dy); ode=(x^2*D2y)-(3*x*Dy)+(3*y)==(2*x^4*(exp(x))) y(x,C1,...

2 Tage ago | 0

Answered
What would be a best interpolation method to get test data for a specific temperature?
I would just use interp1 — TestData = sortrows(randi([0 200], 15, 4),1) InterpTemps = [0 40 100]; Interp_234 = interp1(TestD...

3 Tage ago | 0

Answered
xlsread isn't storing all the cell values from a column
Try something like this — T1 = readtable('YourExcelFile.xlsx', 'Range','A1:E19') That will import everything as a table, and ...

3 Tage ago | 0

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Answered
Output argument "K" (and maybe others) not assigned during call to "linear_kernel".
Why not just — K = dot(x1,x2) instead? See the documentation on the dot function for details.

3 Tage ago | 0

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Answered
The value of equation
I have absolutely no clue as to what you want. Try this — syms x u x3 %x = (0:1:4) L1 = 8; L =...

3 Tage ago | 0

Answered
Calculating the Standard Deviation
Two options are to either calculate it directly, or use the normalize funciton — y = readmatrix('https://www.mathworks.com/mat...

3 Tage ago | 0

Answered
How to Numerically Integrate Vector with Timestep
Use the trapz function (or cumtrapz, dependng on the result you want), The vector with respect to the numeric integration (time...

3 Tage ago | 1

Answered
Getting the area of a surface integral from Matlab
See if simplifying it does what you want — syms phi the x = cos(phi).*sin(the); y = sin(phi).*sin(the); z = cos(the); dens...

3 Tage ago | 1

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Answered
How to process xlsx with readtable for graphs/plots
One approach is to use groupsummary to aggregate the data — T1 = readtable('https://www.mathworks.com/matlabcentral/answers/up...

3 Tage ago | 0

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Answered
Solve for one variable
It really is not at all different, except the format. Examing it — syms p A=0.1199; At=0.112; y=1.43; P1=119; Error =0...

4 Tage ago | 0

Answered
Can you have lines between circles on a scatter plot?
Try this — a = [50:199]; b = [75:224]; i = [1:150]; scatter( i, [a;b] ) [ia,ib] = (ismember(a,b)); aidx = find(ia); hold...

4 Tage ago | 0

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Answered
empty sym: 0-by-1. please help me
a=9.61; b=0.16; fc=2000*10^6; c=300*10^6; A= 10^(1/10)-10^(20/10); B=(20*log10(4*pi*fc/c))+10^(20/10) syms R real; y=...

4 Tage ago | 1

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Answered
Help with Laplace ODE
Try this — syms t y(t) Y(s) Dy0 a b y0 Dy1 = diff(y,t,1); eqn = laplace(Dy1== a*sinh(a*t)) eqn = subs(eqn, {laplace(y(t), ...

4 Tage ago | 1

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Answered
FFT results correct for following filtering?
It is my code ( apparently copied from is the FFT right? ) and I do not see any mistakes in it! That signal and ‘CH0’ here ar...

4 Tage ago | 1

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Answered
Error in ode45 (line 115) and odearguments (line 90)
First, do not use global variables! Pass extra parameters as additional parameters. See Passing Extra Parameters for details....

4 Tage ago | 0

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Answered
Fourier series using matlab
We can’t correct it because you posted an image of it rather the actual code. The solution is straightforward nevertheless — ...

4 Tage ago | 1