Star Strider

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

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Answered
How can I solve this nested symbolic function ?
It would be best to abandon the idea of using the Symbolic Math Toolbox here, since it is not necessary. You can do everythin...

1 hour ago | 0

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Can I calculate the settling time in MATLAB?
Perhaps this — s = tf('s'); G = (7507.852*s^3 - 37030.228*s^2 - 70479.368*s + 100001.744) / (s^5 + 50*s^4 + 1000*s^3 + 10000....

4 hours ago | 0

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how to add percentage symbol (%) in a label
The approach seems to work here using synthetic data — % x=table{:,"Xvalues"}; % y=table{:,"Yvalues"}; x = 1:5; y = round(r...

12 hours ago | 0

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How to change the scale of color bar to discrete ?
Creating a segmented colorbar with specific quantized levels is straightforward. Puttting it in the correct position is not. ...

16 hours ago | 0

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Getting an equation from a signal transfer function
‘I would like to get a mathematical expression for that transfer function’ If you have access to the System Identification To...

1 day ago | 0

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Error using for-loop, keep getting "Index in position 1 is invalid. Array indices must be positive integers or logical values."
The variable and the function have the same names. Change the function name and it works — %% Using single-temperature to p...

1 day ago | 0

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FFT Analysis Issue: Unexpected Harmonic Multiples in Vibration Signal Frequency Plot
It appears that the fft plot as actually a double-sided fft that the function normally produces. The ‘frequencies’ should pro...

1 day ago | 0

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Import data from file
This segments some of the file information into 31 individual cells of character vectors . I have no idea what you want from th...

1 day ago | 0

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make separate table for sets of lat lon that appears x times in a big table.
Use accumarray for this, however we may not be discussing the same file — T1 = readtable('who_ambient_ai...3_(v6.0).xlsx', 'Sh...

2 days ago | 1

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How to mark points at 1-5 on the x-axis in the plot
One possibility — clc; clear all ; Ld=(0:0.00005:0.005); w=0.001; L=0.007; P=4*0.001; Ta=25; h=375; Kf=175; Kd=0.0...

3 days ago | 0

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Answered
Why won't my plot start 0 and increase to 0.005 like my Ld
It does. It just uses the exponent to scale it. Add these lines: Ax = gca; Ax.XAxis.Exponent = 0; to see the tick labels...

3 days ago | 0

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Delete rows of excel if any empty cell found
I am not certain how you want to sort the ‘Station’ by ‘shortest to the longest’. Try this — T1 = readtable('datax.xlsx', ...

3 days ago | 0

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How to graph values of different lengths?
The ‘time’ vector has 10080 elements and ‘EV_power’ has 10230 elements. One way to fix that is to create: time = linspace(0...

3 days ago | 0

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fill the 2D plot
I am not exactly certain what you want (fill below the red line and between the red and blue lines or fill below the red line an...

3 days ago | 0

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How I can plot input signal in ode45
Create a second output for ‘u’ (ode45 will ignore it during the integration) and then return it using a for loop after the integ...

4 days ago | 1

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how to use all the data for a nonlinear regression?
You can only do the regression on complete data rows, so I used the rmmissing function to accomplish that. Try something like...

4 days ago | 1

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Answered
Extract the timing of a specific sound (beep) from an Audio File
It would help to have the file. I assume that the background sounds also contain 300 Hz elements, so unless there is somethi...

4 days ago | 0

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Plotting variables of continuously array with different colors
You can use either unique or findgroups for this to get serial indices — T1 = readtable('datax.xlsx') [Us,ix1,ix2] = unique(T...

5 days ago | 1

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Answered
why ismember() does not return correct result
They may have very small values that are not shown, especially if they are calculated. Using the ismembertol function will li...

5 days ago | 0

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Answered
How to read txt file and put the words on a vector and the numbers in a matrix?
If that is the exact file, readtable is going to have problems with it. Using fgetl and textscan — type('Alexandre_2023_10...

5 days ago | 1

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Answered
I have two set data and I want to calculate the area in different x and plot the area curve with respect to X
Perhaps this — x=[1 1.5 1.7 2 2.2 2.6 2.8]; y=[0 2 6 7 8 10 5]; int_y = cumtrapz(x, y); figure plot(x, y, 'DisplayName',...

6 days ago | 0

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Answered
Drawing a turning tangent on fitted curve
Perhaps this — xvalue = 20:1:30 yvalue = [56.7 59.8 64.8 66.7 66.2 65.2 64.2 63.5 63.0 62.7 62.5] p = polyfit(xvalue, yval...

6 days ago | 1

Answered
How to draw a rectangle around the area that shows an energy variation
It would help to have your data. An adaptive approach using contour3 — Fs = 500; L = 300; t = linspace(0, L*Fs, L*Fs+1)/F...

6 days ago | 0

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Answered
How to make the for loop the length as the array inside the for loop?
You do not need the loop at all. Just use the diff function — x1 = [1e6:20000:5e6]; L = 4e6; % in m D_c = 5000;% in m D1 =...

6 days ago | 0

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Can I create the same FIR filter using two different commands?
Getting the same filter using ttwo differnt methods is probably possible. Comparing a windowed design (using kaiserord here wit...

7 days ago | 0

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Answered
How can I create a bandpass FIR filter using firpm?
I could not get this to work with firpm, since it apparently only works with lowpass filters. Getting it to work with fir1 i...

8 days ago | 1

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Answered
Changing exponential axis scale
I am not certain what the problem is. The approach you took appears to work here (R2023b) — c = 3e+08; % Speed of light in ...

8 days ago | 0

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How To solve this equation?
One approach — syms x f = symsum(((5*x+2)^(1/5))/x, x, 1, 1E+3) fvpa = vpa(f) .

9 days ago | 0

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Adding values to a table
One approach (that works) — DateTime = datetime([2020 01 01]) + calmonths(0:5)'; Incidence = randi(10,6,1); tab = table(Dat...

9 days ago | 0

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Answered
i want to convert my data to time series.
This is a common problem in biomedical signal processing, and is referred to as creating an ensemble. One example using a photo...

9 days ago | 0

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