# 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**

Convenient way to filter sinusoidal noise from decay data?

If you want to use a frequency-selective filter, first do a fft of the data to determine the frequency components, then use the ...

20 hours ago | 0

How to read Brimrose NIR spectral data

I have no idea what is supposed to be in that file. It appears to be a binary file, so experiment with the fread function. A...

21 hours ago | 0

How can I get a smooth curve in MATLAB?

One option is to interpolate to a finer ‘x’ vecttor, and then use a method such as 'pchip', 'spline', 'makima', or others to do ...

1 day ago | 0

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How to integrate a lognormal pdf

The ‘ero’ data are missing. Consider the appropriate cdf function.

1 day ago | 0

Cannot add shaded confidence intervals?

We do not have your data. The fliplr function will not produce the desired result with column data. I prefer to use the patc...

1 day ago | 0

How to use the data from a .mat file to make a graphic?

Use the load function to ‘read’ the .mat file. (I always load into a variable as a structure of the .mat file contents so that ...

1 day ago | 0

A way to write "if x is in y matrix do this"

It depends what the random number is, and how you define ‘y’ . The ismember function works for exact comparisons. The ismember...

1 day ago | 0

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How can I delete a specific row from a timetable?

Try something like this — LD = load(websave('TimeTable','https://www.mathworks.com/matlabcentral/answers/uploaded_files/127871...

1 day ago | 1

| accepted

How to transform a second order ODE to the format xddot=A.X+B.U

See if using odeToVectorField and matlabFunction will do what you want. Those should work if you want to solve them using the...

1 day ago | 0

Convert uint8 vector to float

Since you apparently know the mapping, one option is to simply calculate a linear regression (assuming that a linear relation ex...

2 days ago | 1

How do I plot horizontal time intervals and ignore others to produce a non continous dashed line plot?

Try this — tTime =[0.0547083333333333 0.0553541666666667 0.0587500000000000 0.0599375000000000 0.0632291666666667 0.0646458333...

2 days ago | 0

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How to change a single xtick (x label)?

Perhaps something like this — x = 1:100; y = rand (100); figure plot(x,y) xt = xticks; xticklabels([{'No Stim'} compose...

2 days ago | 0

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find a tangent values from plot

I am not certain what tangent (slope) you want. I am assuming it is from (0,0) to where the tangent line touches each parabols....

3 days ago | 0

Best way for finding transfer function in time domain

If you want to create a filter from it (returning numerator and denominator coefficient vectors), use the Signal Processing Tool...

3 days ago | 0

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How to define the location/position of a number in a specific cell array?

It would help to have the actual cell array. Try something like this — MY = {[]; []; []; 1; []; []; []} loc = find(cellf...

4 days ago | 0

How can I plot this X and Y data?

Perhaps something like this — LD = load(websave('Tide_Data','https://www.mathworks.com/matlabcentral/answers/uploaded_files/12...

5 days ago | 0

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how to separate a large text file into individual text files based on date, but also export headers?

Try something like this — files = {'https://www.mathworks.com/matlabcentral/answers/uploaded_files/1276100/Gwynedd_1991.txt';'...

5 days ago | 0

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Is the window function automatically used when doing the fft function, or do I have to enter code to use the window function?

The fft defaults to a rectangular window that is the length of the signal. That is the only one that is ‘autoomatically’ used. ...

6 days ago | 0

Creating sounds with changing amplitude

Try this — Fs = 44100; Ft = 440; sec = 2; t = linspace(0, Fs*sec*60-1, Fs*sec*60).'/Fs; % ChkFrq = 1/t(2) s = sin(2*pi*Ft...

6 days ago | 0

How to interpret results of FFT/DFT?

The time vector needs to be scaled correctly if the frequency vector is to be correct. Try this — T1 = readtable('https://w...

6 days ago | 0

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Plot a graph from arrays

Try something like this — hv = [0,2,4,6,8]; Xm = [ {[54.8765]} {[15.8544]} {[55.3118]} {[19.0629]} {[55....

6 days ago | 0

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Logical operator not evaluating correctly

Only two comparisons are actually required here — X = linspace(-7, 7, 15); Y = -(X < -5) + (X > 5); Check_Result = [X; Y] ...

6 days ago | 0

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add the magnitude ratio and the phase angles data points on bode diagram

I am not certain what you want for the result. The fit is not the best, however the compare function will plot the data and t...

6 days ago | 0

How to plot a graph correctly?

I am not certain that I understand what you want to do. If you only want the contour at ‘F=0’, supply that as the fourth, ‘Le...

6 days ago | 0

How do I simplify a function?

You apparently defined some of those variables as arrays previously. To use the simplified function numerically, use the matl...

7 days ago | 0

How to covert rownames to the first variable in the table?

Try something like this — T1 = array2table(randi(9, 5, 5)); T1.Properties.RowNames = {'1','2','3','4','5'} ...

7 days ago | 0

How to calculate the derivative of vector

Fro symbolic variables, diff only works with funcitons. To calculate a numeric derivative, try something like this (assuming ...

8 days ago | 0

Ideal way to smoothe gyroscope data

The LPF approach is likely appropriate, and an IIR filter (elliptical is most efficient) is likely the best option. First, de...

8 days ago | 0

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How to remove the value using Histogram

I have only a vague idea of what you want to do, especially since the .mat file does not appear to contain the same data as depi...

8 days ago | 0

what is the correct way to write this expression in matlab?

If ‘R’, ‘L’, and ‘C’ are all arrays of the same size, use element-wise operations in every multiplication, division, and exponen...

8 days ago | 1