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PROFESSIONAL: Physician (M.D.): Diplomate of the American Board of Internal Medicine; M.Sc. Biomedical Engineering: Instrumentation, Signal Processing, Control, System Identification, Parameter Estimation

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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) ...

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) ...

environ 3 heures ago | 0

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 ...

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 ...

environ 5 heures 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...

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...

environ 19 heures 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...

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...

environ 23 heures ago | 0

| accepted

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....

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....

environ 23 heures ago | 1

| accepted

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...

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...

environ 23 heures 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...

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...

1 jour ago | 0

| accepted

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...

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...

1 jour ago | 0

| accepted

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 ...

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 ...

1 jour 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,...

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 jours 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...

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...

2 jours 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 ...

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 ...

2 jours ago | 0

| accepted

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.

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.

2 jours 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 =...

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 =...

2 jours 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...

Calculating the Standard Deviation

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

2 jours 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...

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...

2 jours 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...

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...

2 jours 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...

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 jours 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...

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...

3 jours 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...

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...

3 jours 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=...

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=...

3 jours ago | 1

| accepted

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), ...

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), ...

3 jours 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...

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...

3 jours ago | 1

| accepted

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....

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 jours ago | 0

| accepted

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 — ...

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 jours ago | 1

Answered

Convert signal from time domain to frequency domain with fft

If ‘T’ (that I assume is the time vector) is regularly-sampled (constant sampling intervals), first determine the sampling inter...

Convert signal from time domain to frequency domain with fft

If ‘T’ (that I assume is the time vector) is regularly-sampled (constant sampling intervals), first determine the sampling inter...

4 jours ago | 0

| accepted

Answered

is the FFT right?

‘What is the meaning of the y axis?’ It is necessary to normalise the fft result by the length of the vector it uses as an ar...

is the FFT right?

‘What is the meaning of the y axis?’ It is necessary to normalise the fft result by the length of the vector it uses as an ar...

4 jours ago | 1

| accepted

Answered

Homogeneous differential equation with dsolve => Warning: Unable to find explicit solution.

The differential equation is nonlinear. There are only a few nonlinear differential equations that have analytical solutions. ...

Homogeneous differential equation with dsolve => Warning: Unable to find explicit solution.

The differential equation is nonlinear. There are only a few nonlinear differential equations that have analytical solutions. ...

4 jours ago | 0

| accepted

Answered

how to draw a quadratic equation

It is definitely close to linear in the region you are plotting it. To plot it and see its quadratic shape, find the inflectio...

how to draw a quadratic equation

It is definitely close to linear in the region you are plotting it. To plot it and see its quadratic shape, find the inflectio...

4 jours ago | 0

Answered

Solving linear system - but using only parts of the Matrix

The lsqr function is appropriate here — D = [... 0 0 0 0 0.345265357599750 0.457309520629080 0.548726230994530 0 0 0 0 0 0 0...

Solving linear system - but using only parts of the Matrix

The lsqr function is appropriate here — D = [... 0 0 0 0 0.345265357599750 0.457309520629080 0.548726230994530 0 0 0 0 0 0 0...

4 jours ago | 1

| accepted