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Star Strider


Last seen: en dag ago Active 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

NOTE: I do not respond to emails or personal messages, unless they are about my File Exchange contributions.

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Answered
Find energy for each second of audio file
Use the buffer function: Fs = 44.1E+3; % Sampling Frequency s = randn(Fs*5.2,1); ...

ungefär 8 timmar ago | 0

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Answered
Does anyone know why the second plot doesn't work?
Yes! In line #44, there is a hold off call, although no new figure call, so the subsequent plot overplots the existing plo...

ungefär 8 timmar ago | 0

Answered
function interpolation and root finding
Try this — points = [0.500000000000000 0.500000000000000 0.498097349045873 0.494452298903742 0.49...

ungefär 12 timmar ago | 0

Answered
Track selected cell to an other position
I am not clear on what you want to do. Running this, ‘ROIX’ and ‘ROIY’ are logical arrays. What do you want to do with the...

en dag ago | 0

Answered
Please someone help test run this Matlab code and debug it if possible. Please help a student
The ‘uexact’ variable does not exist, and there is nothing similar to it (for example by a different spelling, at least that I c...

en dag ago | 0

Answered
How to solve damped forced vibration analysis using ode45 ?
One problem is with the ‘dxdt’ assignment. MATLAB interprets the spaces as delimiters, so the second row has 3 columns, as MATL...

2 dagar ago | 0

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Answered
Does anyone know how to add the legend?
I am not exactly sure what you want. First, the clear all and close all calls are not necessary and make your code less effic...

2 dagar ago | 0

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Answered
Write a complex number in polar form
The ‘image below’ is slightly difficult to read, however the code to do that is easy to write. This is called phasor notation. ...

2 dagar ago | 0

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Answered
How To Extract Data from Multiple CSV Files and Run Analysis?
Try something like this — T1 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/693589/data1.csv') T...

3 dagar ago | 0

Answered
How can I plot a trendline that follows the peaks a time-history data set (accelerogram)?
The envelope function could do what you want. Another option is findpeaks, with the appropriate name-value pair arguments. ...

4 dagar ago | 0

Answered
Detect signal clipping and remove
Without an example signal, I am guessing that the ‘clipped’ or ‘railed’ parts of the sound would be equal to ±1, with the valid ...

4 dagar ago | 0

Answered
How to calculate the standard error estimation when using fit from curve fitting toolbox?
Yes. Use the predint function. x = linspace(0, 100, 100); y = -0.3*x + 2*randn(1,100); [f,gof,out] = fit(x(:), y(:), ...

4 dagar ago | 0

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Answered
Create a graph from 2 vectors and a matrix
I would use surf or mesh: figure surf(X,Y,Z.', 'EdgeColor','none') to see it from the top, add: view(0,90) ,

4 dagar ago | 0

Answered
How to get wrapped phase data from unwrapped phase data
According to the unwrap documentation, unwrapping takes the original and adds radians to phase angles that originally go from ....

4 dagar ago | 0

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Answered
the findpeaks function does not seem to work for me
The findpeaks function is in the Signal Processing Toolbox. You will have to have it licensed and installed to use the function...

4 dagar ago | 0

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Answered
How to conditionally merge multiple variables in a table
Concatenate them horizontally uising square brackets [], then assign the name to the new variable — var_a = [1:10]'; var_b = ...

4 dagar ago | 0

Answered
Display an Error Message
The code works. The if logic is the opposite of what you indicated that you want. Correcting that (and a couple other small ...

4 dagar ago | 0

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Answered
How can I convert the serial date numbers in a text file to calendar dates
It appears to be a MATLAB date number, and if so, maps to 1 Jan 1979 10:00:00 — DT = datetime(722816.416666667, 'ConvertFrom',...

5 dagar ago | 0

Answered
WHY DO I GET THIS ERROR USING THE ERROR BAR AND PLOT?
The errorbar call should be: errorbar(x, MODESTAMMEQ.Var5, MODESTAMMEQ.Var4,'.r','MarkerSize',6) since ‘MODESTAMMEQ.Jan1989’ ...

5 dagar ago | 0

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Answered
Determine percent of array elements which meet condition
A logical array has two states, true=1 or false=0, so al that is necessary is to find the numbers of 1 values with respect to th...

5 dagar ago | 0

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Answered
Binning data into equally spaced intervals
One approach — v = rand(1,1000)*2000; edges = 0:5:2000; [counts,edg,bin] = histcounts(v, edges); % ...

6 dagar ago | 0

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Answered
WHY CAN'T I PLOT THIS WITH "DATETIME"?
The first column is not a valid datetime array. It first needs to be converted to one. Try this — LD = load('LARSEN_MMEQ1....

6 dagar ago | 0

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Answered
Overlaying scatter plot on grouped bar graphs
The ‘all’ matrix is (16x3), however there are 12 bars (3 groups of 4). Ths size of ‘all’ is not consistent with that. How is...

6 dagar ago | 0

Answered
Adding error bars to a plot
I do not understand what you want to do, although that is definitely possible. Examples — y = rand(4,3)*10; err = rand(4,3...

6 dagar ago | 0

Answered
how to Concatenate big string matrices of different sizes
I would read all of them in as table arrays using readtable, then use the innerjoin function to join the first two tables, then ...

6 dagar ago | 0

Answered
2D Graph Plot from excel data
I have absolutely no idea what you want to plot, and the data posted do not give anything similar to the plot image. Other th...

6 dagar ago | 0

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Answered
Matlab fitting image is inconsistent with the parametric equation
Try this — year=[1750 1800 1850 1900 1950 1990 2000 2009]; % population(millions)=[791 980 1260 1650 2520 5270 6060 6800]; p...

6 dagar ago | 0

Answered
Draw 3D plot from 2D plot with discrete data points
Without the Excel file, I experimented to create an approsimately equal curve. I then used it as the radiuc argument to the cyl...

6 dagar ago | 0

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Answered
What is ind2sub
MATLAB uses linear indexing for arrays, however many arrays are also referred to by subscripts into the rows, columns, and addit...

6 dagar ago | 1

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Answered
Different frequency responses using [z,p,k] method and [b,a] for 2nd order elliptical filter
You are doing everything correctly, however you only need to use the second-order-section (‘sos’) representation, since it essen...

6 dagar ago | 0

| accepted

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