# Star Strider

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. Time Zone: UTC-7 (Standard); UTC-6 (Daylight Savings/Summer)

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**Content Feed**

Impulse response function (IRF) of data set

I’m not certain if it’s possible to define the impulse response of an electromyogram, however I have no idea what your data are....

5 hours ago | 1

How to smooth contour lines for the given set of data

Increase the resolution of the vectors (and resulting matrices), and optionally define the 'method' as something other than 'lin...

6 hours ago | 0

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How to mesh plot sum of sine waves

Give it the ‘X’ and ‘Y’ matrix arguments rather than the vector arguments — x=-1:0.01:1; y=-1:0.01:1; [X,Y]=meshgrid(x,y); ...

8 hours ago | 0

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smoothing a graph using matlab

There are several opotions, including sgolayfilt and smoothdata and frequency-selective filters — y = readmatrix('https://www....

10 hours ago | 0

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How would I use fsolve for 3 unknowns and 3 equations?

Provide values for ‘Qt’ and ‘Qm’ and then solve it — clear;clc;format long; lm1=0; %m lm2=-0.2; %m Am=95; %m^2 At=3; %m^...

1 day ago | 0

Wilcoxon 'signrank' test zval is not calculating

The ‘zval’ is only returned when the 'method' is 'approximate'. There is no statistical difference between the vectors: [p,...

1 day ago | 0

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How do I put the patch in the correct position?

It appears that the ‘x’ and ‘y’ axes are reversed with respect to the data and the percentile patches. Keep the percentile patc...

1 day ago | 0

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Identify Zerocrossing Indices near to the peak of the other signal matlab

The file is too large to download here, and the online Run feature still has problems with .mat files. That aside, finding th...

1 day ago | 0

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Convert from transfer function to time domain

Probably the easiest way is to just simulate it. R0=0.000605797; Qr=147964.8608; R1=0.000856205; C1=0.049823238; % X=[SOC...

2 days ago | 1

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combining 2 ECG signal into 1

Unless the row vectors ‘xn’ and ‘xaf’ have the same number of elements, the vertical concatenation to produce ‘xc’ is going to f...

2 days ago | 0

Choosing the Axis for Interp2?

Use plot3 instread of plot, since the plot is in three dimensions — X=-1:0.1:1; Y=-1:0.1:1; Z=membrane(1,10,10); figure(1...

3 days ago | 0

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how to make a cross section of lines and connect cross sections?

I do not have your data, however consider something like this — It would appear that the ‘y’ value is fixed in any specific lo...

3 days ago | 0

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Proper Labeling of X & Y values Contour Plot

Use the tick label properties to change the tick labels. Any new tick values have to be in the ranges of the current tick value...

3 days ago | 0

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how to make a boundary using percentile?

This uses the prctile function — x = rand(1,1000)*10+125; y = randn(1,1000)*50+250; xpctl = prctile(x,[2.5 97.5]) ypctl ...

3 days ago | 0

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Is there a function to make a long list of a single value?

Try this — Fives = 5*ones(400,1) .

4 days ago | 1

| accepted

Understanding this FFT Graph

‘My question is; what would the label be for the Y-axis and secondly, is the X axis just frequency in the time domain?’ The Y...

5 days ago | 0

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FFT Analysis of Sine Sweep

Your posted code is likely as good as it is possible to get. I added a pspectrum call at the end — T=5; %size of window fs...

5 days ago | 0

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Time response of modes to an impulse

If I understand correctly what you want, it is possible to return the state trajectories with lsim as described in Extract Simul...

5 days ago | 0

Reading complicated CSV file

Try something like this — C1 = readcell('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1007390/random.csv'); ...

6 days ago | 1

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How to solve a nonlinear system with 6 equations but with only 4 variables?

Use the mldivide, \ operator to do a least-squares determineation of the system. See the documentation for details. .

6 days ago | 0

Problem with cycle within a cycle output

If I understand correctly what you want to do, in every ‘j’ iteration, ‘h’ needs to be reinitialised, so: h = 1; whil...

6 days ago | 0

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Precise Prediction Model Development

What are you predicting? How does ‘y’ fit in with this? Is it a separate vector? With those concerns met, building the ...

6 days ago | 0

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How to filter noise in EMG signal - Tibialis anterior muscles

First, before calculating the fft, subtract the mean of the signal to eliminate the D-C (0 Hz) spike so the other peaks are more...

6 days ago | 0

How to match the rising starting point of the graph

This is my best effort. I could not get the other functions I tried (ischange, findchangepts, islocalmin, etc.) to work, so I w...

7 days ago | 2

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I exported data from excel into a table, how do I sum the values of each column from that table excluding NaN's

Two options — T = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1005700/Inventory.xlsx') S1 = nan...

8 days ago | 0

How to overcome the problem with the function diff used to approximate matrix derivative.

Use the gradient function instead of diff.

8 days ago | 0

How to interpolate a column array based on another non-linearly spaced column array?

As a general rule, it is best to interpolate a longer vector to a shorter vector in order to avoid creating data that interpolat...

8 days ago | 0

Incorrect use of '=' operator for an IF statement

I usually do something like this in setting an index range — L = numel(Componentry_New) for k = 1:Whatever Level_Either_...

8 days ago | 0

Trying to learn how to add a threshold trigger and peak markers.

Try something like this — x = linspace(0,10,500); red_line = sin(2*pi*x)*1.5; trigger = find(diff(sign(red_line - 0.95)));...

9 days ago | 0

| accepted