# 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**

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...

etwa 7 Stunden ago | 0

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

Use the gradient function instead of diff.

etwa 10 Stunden 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...

etwa 13 Stunden 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_...

etwa 14 Stunden 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)));...

ein Tag ago | 0

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What does this Digital filter actually do? and what is it called?

It is a 2D FIR filter: I am not certain it has any other name. To see what it does, plot its results — H = [1 1 1 1 1;1 2...

ein Tag ago | 0

How to add date and time in a plot by command in matlab 2012?

I no longer have access to R2012a, so I cannot test this with it. The code you posted works correctly in R2022a, however R201...

ein Tag ago | 0

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Three columns (x,y,z) in table, Loop through table for each X plot Y vs Z

Try this — CA = {'A' 1 3 'A' 2 4 'A' 3 10 'B' 1 4 'B' 2 4 'B' 4 6 'C' 0 1 'C' 1 4 ...

ein Tag ago | 0

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How to implement a for loop on figure plotting?

Try something like this f = 1:500; Q = randn(115,500); idx = 1:100; % Choose Specific Columns fi...

ein Tag ago | 0

I want to find the area of the graph

Try this — LD = load('x,y.mat'); x = LD.xy(1,:); y = LD.xy(2,:); yf = sgolayfilt(y, 3, 1001); ...

2 Tage ago | 1

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Can "datetime" be responsible for the misalignment of data in a plot ?

The first cluster of data (at about 2.5 or about 18 Jun) appears to be perfectly aligned in both plots. The datetime plot goes...

2 Tage ago | 1

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How can I add uncertainty to a data matrix?

The repmat funciton is likely not needed. Just do something like this: h = h + randn(size(h)); and so for the rest. See t...

3 Tage ago | 0

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ERROR: Array indices must be positive integers or logical values. Can anyone please help, Thank You!

I suspect the problem is with this term — u(u*UmaxN_0+PsByN_0*u) and everywhere else something similar to that is used. The ...

3 Tage ago | 0

Why doesn't my state-space model iterate?

The iterations are defined inside the function. See the documentation section on Display to see the progress of the estimation....

3 Tage ago | 0

How to FFT my xlsx files from time domain to frequency domain?

Try this — T1 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1000730/delay%2040ms%20speed%20100%2...

3 Tage ago | 0

Extend a cell array of dates (from days only, to hours and days) in a compact way

Try this — C1 = {'17-Jun-2017'; '30-Jul-2017'} DT1 = [datetime(C1{1}) : days(1) : datetime(C1{end})]' DT2 = [min(DT1): hou...

4 Tage ago | 1

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How to utilize 'symsum' in this case?

Try something like this — syms i j t Y Eq = symsum(Y,j,2,5) * (symsum(t,i,1,j)^2 - symsum(t,i,1,j-1)^2) .

4 Tage ago | 0

I am trying to find the integral gain (ki) of the following transfer function.

Symbolic variables are not permitted in Control System Toolbox objects, however anonymous functions are. Try this — sys = @...

4 Tage ago | 0

Scatterplot with two x and y axes only showing one dataset

The code only creates one tile: t = tiledlayout(1,1); Changing it to: t = tiledlayout(1,2); or: t = tiledlayout(2,1); a...

4 Tage ago | 0

How to solve third order equation using ode45

I let the Symbolic Math Toolbox do everything — syms y(t) T Y Dy = diff(y); D2y = diff(Dy); D3y = diff(D2y); Eq = D3y - D...

4 Tage ago | 1

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COnvert x,y, time array into 3D matrix

Try this — xyt = [1, 3, 2 1, 3, 2.3 1, 3, 2 1, 3, 2.1 1, 3, 2.4 4, 5, 1 4, 5, ...

4 Tage ago | 0

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how can I change the code to have only unique CDF and PDF plot?not for all samples

I am not absolutely certain what you want. If you want one plot for the first and last subplots, rather than multiple lines i...

4 Tage ago | 1

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Need explanation on plotting frequency response of a causal discrete-time LTI system implemented using the difference equation.

‘does it mean H=RH_coeff, w=LH_coeff?’ No. The first argument are the numerator coefficients of the filter transfer function...

5 Tage ago | 1

Obtaining value of highest order derivative over simulation period

One option would be to use the gradient function on the second column of the differential equation output (the integrated functi...

5 Tage ago | 0

bandpass filter design from low-pass iir filter

See if the lp2bp function will do what you want.

5 Tage ago | 0

How to make a table of strings from a table of numerics

I’m not certain what you want, however substituting compose for sprintf may be appropriate — arr = [1;2;3;4]; T = array2table...

5 Tage ago | 0

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3d surface plotting of spherical coordinates which i have in csv

Apparently, the angles sent to sph2cart were in degres, not radians. Try this with the complete file — M = [20 0 ...

5 Tage ago | 0

Help on ploting bar graph using table

There are mismatches between the number of names and the number of variables, and a missing comma between ‘Protein L’ and ‘Prote...

5 Tage ago | 0

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Modifying 3D plot

There are only two points, so I am not certain what you want for the others. One option could be to use stem3 instead — x =...

5 Tage ago | 0

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removing pops/clicks from audio file

The filloutliers function (or one of its friends) could be an option — [y,Fs] = audioread('https://transfer.sh/fR2wht/vinyl.mp...

5 Tage ago | 0

| accepted