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Star Strider


Last seen: Today
13.463 total contributions 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

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Answered
Need to solve the roots from a large equation
Use the correct values for ‘la’ and ‘n’, then this: syms k la = 42; n = pi; Eqn = 2*k - 2*k*n + (8*k^7*n^4 - 24*k^5*n^3 + ...

alrededor de 7 horas ago | 0

Answered
Find Middle of square wave
Use the islocalmax function (R2017b and later): This code plots green upward-pointing triangles at the centre of each pulse: ...

alrededor de 16 horas ago | 0

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Answered
Change color of a specific line in mesh
No exact solutions without your code and data. One approach: xv = -15:0.8:15; yv = -10:0.8:10; [X,Y] = ndgrid(xv, yv); z...

alrededor de 19 horas ago | 1

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Answered
Calculating efficiency using matlab
No loops needed: Tout = [323.2 326.0 328.8 331.6 334.3 337.1]; I = [500 550 600 650 700 750]; [Toutm,Im] = ndgrid(Tout,I...

alrededor de 20 horas ago | 0

Answered
Vary a parameter and plot the output
Try this: function main x0 = [500 500 500 500 5 5]; opt = optimset('Display','off'); % 'display', 'iter' I = [500 550 600 ...

1 día ago | 0

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Answered
How do I avoid using a lot of if statements in a row?
Another option is switch,case,otherwise. You will need to determine if that is an improvement over the multiple if blocks.

2 días ago | 0

Answered
Stability Analysis (Dertermining the Limit Cycle)
The phase portrait is usually plotted as the function against its derivative. Use the gradient function to calculate the deriva...

2 días ago | 0

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Answered
Peak to Peak Value of Sinusoidal Grad
Use the islocalmax function to find the maxima, islocalmin to find the minima, and go from there. (These functions were introdu...

2 días ago | 0

Answered
Solve numerically a system of first-order differential equations
Create the function symbolically: syms a b c d e f g t x(t) y(t) z(t) T Y Dx = diff(x); Dy = diff(y); Dz = diff(z); Eqn1 ...

3 días ago | 1

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Answered
Finding Angular Frequency of an Oscillation
Likely the easiest way would be to find the times of the positive peaks, then calculate from there: [pks,pktimes] = findpeaks(...

3 días ago | 1

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Answered
filter a timetable by day
I am not certain what you intend by ‘groups’. One option is to use the retime function: TTRT = retime(TT, 'daily','mean') ...

3 días ago | 0

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Answered
how do i keep the format of xticklabels?
Use compose or sprintfc to create the cell array of labels: figure plot(0:6, rand(1,7)) xtl = sprintfc('%d',10.^(0:6)); xtl...

3 días ago | 0

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Answered
creating plane piecewise in one plot
Try this: f = @(x) (3*x).*((0<x) & (x<=1)) + (2*x+1).*((1<x) & (x<=2)) + (6*x+1).*((2<x) & (x<=3)); x = linspace(0, 3); ...

3 días ago | 0

Answered
Shading the Standard Deviation
Try this (obviously with your data, not my simulated vectors): x = 1:50; ...

4 días ago | 1

Answered
"dsolve" gives some extra terms in the solution
Tell simplify to keep simplifying until it either meets the iteration limit or cannot simplify the expression further: Vs= sim...

4 días ago | 0

Answered
Nans values in time series
You must decide that. There are methods to interpolate the NaN values if you want to do that, one of which is the fillmissing...

4 días ago | 0

Answered
How can I solve an equation containing log ?
Use the fsolve function, because it will return complex results, and since the argument to the log function is negative it will ...

5 días ago | 0

Answered
How to find maximum of a function of 2 variables
One approach: z = @(x,y) cos(x.^2 + y.^2); XY = fminsearch(@(b)norm(-z(b(1),b(2))), [3; 3]) producing: XY = 2...

5 días ago | 1

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Answered
convert a transfer function to controllable and observable canonical form
num = [4]; den = [1 0.8 4]; Gp = tf (num , den); The canon function requesting the 'companion' canonical form directly produc...

5 días ago | 1

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Answered
why do I get "Undefined function or variable 'tspan'."
The code defines that variable as ‘timespan’. The argument names and the varialble names must always match. Try this: [t,z...

5 días ago | 1

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Answered
How to graph values of a function above and below 0 as separate functions?
Subscript the elements and provide corresponding time vectors for each one: t= 0:0.2:3*pi; y=sin(t); for k = 1:numel(t) ...

6 días ago | 1

Answered
plot function y axis
Put: ylim([1 100]) after the plot call.

6 días ago | 0

Answered
plot function y axis
Put: ylim([1 100]) after the plot call.

6 días ago | 0

Answered
How can I combine several file.fig together
For each .fig file: F = openfig(filename); Lines = findobj(F, 'Type','Line'); Then, for each element of the ‘Lines’ array: ...

6 días ago | 0

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Answered
Use entries of symbolic array outside of the array
The reason is that the elements of ‘X’ are stored as matrix elements. The individual elements exist only as matrix elements, no...

6 días ago | 0

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Answered
What should the order of my FIR filter be?
The fir2 function documentation appears to favour even-numbered filter orders. (The only MATLAB functions that I know of that c...

6 días ago | 0

Answered
Finding and Graphing FWHM (Trouble with Find Function)
Without ‘data_10micronslit.txt’, it is impossible to provide a specific solution. However the findpeaks function will return th...

7 días ago | 0

Answered
Extend linear regression line to an offset
I am not certain what you are asking. Two possibilities: X = [0.6,1.6,2.6,3.6,4.6,5.6,]; Y = [23500, 87780, 153651, 220054...

7 días ago | 0

Answered
Can someone please help?
There are some problems. First, ‘pv’ is not a function of ‘phi’, at least as written. Second, use element-wise operations ...

8 días ago | 0

Answered
How to filter a signal with lowpass/highpass?
The easiest way to determine the sampling frequency is to measure it: D = load('trial1.mat'); A = D.Intensity; t = D.Time; ...

8 días ago | 1

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