12,413 total contributions since 2012

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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 do a nonlinear fit using least squares

This is actually a linear problem, so a linear approximation will estimate the parameters correctly: R = 8.314462; ...

How to do a nonlinear fit using least squares

This is actually a linear problem, so a linear approximation will estimate the parameters correctly: R = 8.314462; ...

11 hours ago | 1

| accepted

Answered

Finding matrix values associated with plot point

One approach: A = rand(10,2); A(4,:) = [75 0.995]; Lrow = ismembertol(A, [75 0.995], 0.01, 'ByRows',1) RowNr = find(Lrow)...

Finding matrix values associated with plot point

One approach: A = rand(10,2); A(4,:) = [75 0.995]; Lrow = ismembertol(A, [75 0.995], 0.01, 'ByRows',1) RowNr = find(Lrow)...

12 hours ago | 0

Answered

Unable to save data or continue through loop

I can’t run your code. However, since you are not defining the character array ‘Filenamesave’ as a cell array earlier in your c...

Unable to save data or continue through loop

I can’t run your code. However, since you are not defining the character array ‘Filenamesave’ as a cell array earlier in your c...

14 hours ago | 0

Answered

Can get the low pass filter to filter the data properly

It is difficult to determine what the problem is without knowing more about the signals. A FIR filter (exspecially a long FIR f...

Can get the low pass filter to filter the data properly

It is difficult to determine what the problem is without knowing more about the signals. A FIR filter (exspecially a long FIR f...

16 hours ago | 0

Answered

Calculate slope at specific time over many days using polyfit and for loop

You appear to be calculating them correctly, just not storing them correctly. For a linear fit, polyfit will produce a (1x2) ve...

Calculate slope at specific time over many days using polyfit and for loop

You appear to be calculating them correctly, just not storing them correctly. For a linear fit, polyfit will produce a (1x2) ve...

16 hours ago | 0

| accepted

Answered

How can I create a legend on the interception of 2 lines on a plot with its coordinates?

I demonstrated how to do that in: How can I interpolate a point in a x,y graph given only one of these values and being the poin...

How can I create a legend on the interception of 2 lines on a plot with its coordinates?

I demonstrated how to do that in: How can I interpolate a point in a x,y graph given only one of these values and being the poin...

17 hours ago | 0

Answered

unable to use Low pass filter on experimental data

When I substitute some vectors for the missing data, the posted code runs for me without error. The filter function should ta...

unable to use Low pass filter on experimental data

When I substitute some vectors for the missing data, the posted code runs for me without error. The filter function should ta...

19 hours ago | 0

| accepted

Answered

Isolating a single pulse by removing noise

Try this: A = dlmread('F0000CH1.csv',",",0,3); Time = 1e9.*A(:,1); Voltage = A(:,2); figure plot(Time,Voltage,'LineWidth...

Isolating a single pulse by removing noise

Try this: A = dlmread('F0000CH1.csv',",",0,3); Time = 1e9.*A(:,1); Voltage = A(:,2); figure plot(Time,Voltage,'LineWidth...

1 day ago | 1

| accepted

Answered

How to change the time increment of a text file to make a new data set from an existing one?

Use interp1: A = [1.1 7 8 5 1.2 8 9 4 1.3 9 10 3 1.4 10 11 12 1.5 11 12 1]; NewCol1 = min(A(:,1)) :...

How to change the time increment of a text file to make a new data set from an existing one?

Use interp1: A = [1.1 7 8 5 1.2 8 9 4 1.3 9 10 3 1.4 10 11 12 1.5 11 12 1]; NewCol1 = min(A(:,1)) :...

1 day ago | 0

Answered

Grid of values spacing in logarithmic scale

I am not certain what you want. Try this: xv = logspace(-5, -1, 25); yv = linspace(0, 1, numel(xv)); figure semilogx(x...

Grid of values spacing in logarithmic scale

I am not certain what you want. Try this: xv = logspace(-5, -1, 25); yv = linspace(0, 1, numel(xv)); figure semilogx(x...

2 days ago | 0

| accepted

Answered

How do I solve the inverse kinematics of a nonlinear differential equation?

You can use the techniques in: Parameter Estimation for a System of Differential Equations. You can likely optimise with respec...

How do I solve the inverse kinematics of a nonlinear differential equation?

You can use the techniques in: Parameter Estimation for a System of Differential Equations. You can likely optimise with respec...

2 days ago | 0

Answered

I have a *.wav file. How do I change the bit rate(bits per sample) of it?

The only way I am aware of to change the bit rate is to read the audio file using audioread, then write it with audiowrite using...

I have a *.wav file. How do I change the bit rate(bits per sample) of it?

The only way I am aware of to change the bit rate is to read the audio file using audioread, then write it with audiowrite using...

2 days ago | 0

| accepted

Answered

How can I graph exponential functions?

First, do not use the exponentiation operator here: y1 = (2*exp(-2*t)-7*exp(-2*t)+0.6)/(4*exp^(-2*t)); ...

How can I graph exponential functions?

First, do not use the exponentiation operator here: y1 = (2*exp(-2*t)-7*exp(-2*t)+0.6)/(4*exp^(-2*t)); ...

2 days ago | 0

Answered

Plot 2D points in 3D space

Since your trajectory is defined by two vectors, if you want to plot it in 3D space, you need to provide another vector. The ea...

Plot 2D points in 3D space

Since your trajectory is defined by two vectors, if you want to plot it in 3D space, you need to provide another vector. The ea...

3 days ago | 0

Answered

How can I interpolate a point in a x,y graph given only one of these values and being the point on the line?

Try this: x = 1:10; y = rand(1,10); figure plot(x,y) hold on xl = xlim; plot(xl(:)*[1 1], [1;1]*[0.5 0.9], '--r') hol...

How can I interpolate a point in a x,y graph given only one of these values and being the point on the line?

Try this: x = 1:10; y = rand(1,10); figure plot(x,y) hold on xl = xlim; plot(xl(:)*[1 1], [1;1]*[0.5 0.9], '--r') hol...

3 days ago | 0

Answered

plotting data from data files and saving each plot through out each run of the loop

You are likely seeing only the plot of the last file read. It is likely best to do the fiie reading and plotting in separate ...

plotting data from data files and saving each plot through out each run of the loop

You are likely seeing only the plot of the last file read. It is likely best to do the fiie reading and plotting in separate ...

3 days ago | 0

Answered

How to get period and frequency components of a signal?

A one-sided Fourier transform is a bit easier to interpret: % Ex 1B % Load the file load("xp.dat"); f_s = 8192; %sample f...

How to get period and frequency components of a signal?

A one-sided Fourier transform is a bit easier to interpret: % Ex 1B % Load the file load("xp.dat"); f_s = 8192; %sample f...

3 days ago | 0

Answered

Error: Index in position 1 is invalid. Array indices must be positive integers or logical values.

The problem is that ‘i’ and ‘j’ are initially both 0. I also did what I could to speed up your code, although it is still ext...

Error: Index in position 1 is invalid. Array indices must be positive integers or logical values.

The problem is that ‘i’ and ‘j’ are initially both 0. I also did what I could to speed up your code, although it is still ext...

3 days ago | 1

| accepted

Answered

Entering state space model into matlab and using ode45 for non-linear thrust force

You willl need to write a function file for your system. See Function Basics for details. For the input, see the ode45 docum...

Entering state space model into matlab and using ode45 for non-linear thrust force

You willl need to write a function file for your system. See Function Basics for details. For the input, see the ode45 docum...

3 days ago | 0

Answered

Array indices must be positive integers or logical values.

The code you posted runs for me without error. What line is throwing the error when you run it?

Array indices must be positive integers or logical values.

The code you posted runs for me without error. What line is throwing the error when you run it?

3 days ago | 1

| accepted

Answered

Convert 99 1x6 to six 1x99 vectors

Concatenate them vertically to get a (99x6) matrix, then transpose the matrix.

Convert 99 1x6 to six 1x99 vectors

Concatenate them vertically to get a (99x6) matrix, then transpose the matrix.

3 days ago | 0

Answered

Designing a differentiator filter using cfirpm

The moving average filter is easy enough to design: Fs = 250; % Sampling Frequency (Hz) ...

Designing a differentiator filter using cfirpm

The moving average filter is easy enough to design: Fs = 250; % Sampling Frequency (Hz) ...

4 days ago | 0

| accepted

Answered

Display time on x axis

It depends on what options you have. For datetime arrays, see Plot Dates and Durations. If you are using datenum date numb...

Display time on x axis

It depends on what options you have. For datetime arrays, see Plot Dates and Durations. If you are using datenum date numb...

4 days ago | 0

| accepted

Answered

getting the max and its positions from a 4D array

Try this: A = rand(3,3,3,3); % Create Array Amax = max(A(:)); ...

getting the max and its positions from a 4D array

Try this: A = rand(3,3,3,3); % Create Array Amax = max(A(:)); ...

4 days ago | 2

Answered

How to normalize two waves on a single plot

Try this: t=0:0.001:0.05; y= 11.18*cos(60*pi*t+26.565); y2= -60*pi*11.18*sin(60*pi*t+26.565); title('Phasor Waveforms') ...

How to normalize two waves on a single plot

Try this: t=0:0.001:0.05; y= 11.18*cos(60*pi*t+26.565); y2= -60*pi*11.18*sin(60*pi*t+26.565); title('Phasor Waveforms') ...

4 days ago | 1

| accepted

Answered

How can I combine multiple wav files into a single new wav file

Use audioread to read them, then vertically concatenate them (assuming they all have the same numbers of channels=columns) using...

How can I combine multiple wav files into a single new wav file

Use audioread to read them, then vertically concatenate them (assuming they all have the same numbers of channels=columns) using...

5 days ago | 0

Answered

how to plot empirical cdf in matlab release 2013a

One approach: x = randn(100,1); % Create Data binrng = linspace(-5, 5, 26); ...

how to plot empirical cdf in matlab release 2013a

One approach: x = randn(100,1); % Create Data binrng = linspace(-5, 5, 26); ...

5 days ago | 0

| accepted

Answered

finding real roots of polynomials

With only symbolic variables, it is not possible to determine if any of the roots are complex, unless one or more of the variabl...

finding real roots of polynomials

With only symbolic variables, it is not possible to determine if any of the roots are complex, unless one or more of the variabl...

5 days ago | 0

Answered

How to calculate the rate using a given data set?

You are not coding your differential equations and data correctly. See for example: Parameter Estimation for a System of Differ...

How to calculate the rate using a given data set?

You are not coding your differential equations and data correctly. See for example: Parameter Estimation for a System of Differ...

5 days ago | 0

Answered

convert time to frequency domain

To normalise it to a maximum value of 1, divide the Fourier transformed data by the maximum of the Fourier transformed data: D...

convert time to frequency domain

To normalise it to a maximum value of 1, divide the Fourier transformed data by the maximum of the Fourier transformed data: D...

5 days ago | 0

| accepted