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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 to use num2str inside text with latex interpreter?
I prefer to use sprintf for this. (If you use any escape characters, you need to use double backslants. See the documentation ...

2 hours ago | 0

Answered
Error when trying to plot a polynomial with data.
Use the polyval function.

5 hours ago | 0

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Answered
How to fit my data with a custom equation meant to come out as a parabola?
The ‘constant’ (parameter vector) is giving back three values because you are giving it three values to begin with: [min(avera...

8 hours ago | 0

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Get Lapalce transform from filter specifications
Not that I am aware of, however it would be relatively straightforward to create it — Rp = 1; Rs = 50; [b,a] = ellip(5, Rp,...

11 hours ago | 0

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How to properly set ticks, numbers and the their decimal places on colorbar?
Try something like this — [X,Y,Z] = peaks(50); figure surf(X, Y, Z) grid on colormap(turbo) hcb = colorbar; % get(hcb)...

12 hours ago | 0

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Answered
How to evaluate numeric expression in a string, which contains "12u" (for 12e-6) and "0.1m" (for 0.1e-3) formated numbers (standing for micro and milli)?
Here is my regexprep attempt at ‘seval’ — str = 'max(1u,2m)'; out = seval(str) str = 'max(1.5u,2.01m)'; out = seval(str) ...

14 hours ago | 0

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Answered
System Identification Toolbox with Multiple Input Variables and one Output Variable
If by ‘parameter’ you mean inputs and outputs respectively, yes. See the iddata section on Input Arguments, then define the s...

15 hours ago | 0

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Answered
Error tolerance in matlab
Singularities occur when the denominator of a fraction approaches zero, or for certrain transcendental functions (e.g. exp, tan)...

15 hours ago | 0

Answered
Time Domain Data or Correct Data Structure for System Identification Toolbox
The signals appear to be regularly sampled, so that should work. The iddata function is an appropriate starting point for time ...

1 day ago | 0

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Answered
help create a positive sin wave
Perhaps — syms t positive_sine = sin(2*pi*t) + 1 figure fplot(positive_sine, [0 5]) grid ylim([-1 3]) hold on yline(0,...

1 day ago | 1

Answered
System of Nonlinear Equations exceeds function evaluation limit
You need to tell fsolve that the options sturcture exists — g = 9.81; Az_mech = 0.028*g; Az_dyn = 0.5*g; Ax_mech = 0.092*g;...

1 day ago | 1

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Answered
Plot will not graph lines
The ‘d’ values are all scalars. Perhaps plooting the ‘y’ values as a function of their associated ‘x’ values — g = 9.81; v...

1 day ago | 0

Answered
fitlm and exponential model help
The "exponential" option for modelspec does not appear to exist. The fitnlm function is likely more appropriate. That is mor...

1 day ago | 0

Answered
Graph not showing plots
The loop is not necessary. However if you choose to use it, the variables must be subscripted in order to save them to vectors ...

1 day ago | 0

Answered
vector partial derivative of a two variable function
Use the gradient function — x=[0:0.1:1]; y=[0:0.1:1].'; z=x.^2+y.^2; [Dx,Dy] = gradient(z) figure surf(x,y,z) hold o...

2 days ago | 0

Answered
Date/Time Processing and Formatting Issues
The 'yyyy' needs to be 'uuuu' (ISO year) to avoid problems with the conversion — C = {'2022:246:10:00:02.593994140',4.44E+01 ...

2 days ago | 0

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Answered
MATLAB is not displaying my numbers as what they should be.
Use the format function to display the data as you want them.

2 days ago | 0

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Answered
How to find inflection point of a curve
First, use the sgolayfilt function to eliminiate as much of the noise as possible, since taking the derivative will amplify it. ...

3 days ago | 2

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Answered
Creating a log probability plot for particle size distribution
See the Statistics and Machine Learning Toolbox probplot function.

3 days ago | 1

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Answered
Print different name than that of the index in figure inside for loop
Probably the easiest way would be to specify a vector for the names and index into it — v = [10 100:100:900]; for i = 1 : 10 ...

3 days ago | 0

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Answered
Formatting exel import in readtable()
It would help to have the Excel file to experiment with. In its absence see the documentation on detectImportOptions and expe...

3 days ago | 1

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Answered
problem using the solve method
‘but matlab wont give me an exact solution’ Yes, it will — syms t eqn = 1000/(exp(log(4) - t/40) + 1) == 800; ts = solve(...

3 days ago | 1

Answered
Application of Logical operators
Perhaps something like this — figure hold on for k = 1:4 patch([1 2 2 1]+2*(k-1), [1 1 4 4], 'b', 'FaceAlpha',0.5) ...

3 days ago | 0

Answered
Does MATLAB have inverse tangent integral TI2(z)?
The polylog function exists in the Symbolic Math Toolbox. It supports symbolic and numeric (double) arguments.

4 days ago | 0

Answered
How do I apply a function to every resulting element of a buffer function?
‘How do I apply a function, e.g. hamming(256), to each column?’ Do an element-wise multiplication — v = randn(256,2) vh ...

4 days ago | 0

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Answered
How can I fix "Error in sym/subsref (line 898) R_tilde = builtin('subsref',L_tilde,Idx); ?
Perhaps — syms xQ xQ = sym('xQ',[1 3]) xQ2 = xQ(2) See the documentation on sym for details.

4 days ago | 0

Answered
Second order to first order system
One approach (that involves doing an interim Laplace transform on the differential equation) — omega = 2; zeta = sqrt(3)/4...

4 days ago | 0

Answered
Saving population individauls for each generation of GA Multiobjective optimisation.
I created a function for ga (not the multiobjective version) that will do that. See if the approach in How to save data from Ge...

5 days ago | 0

Answered
Sometimes my 2-D plots won't show up.
Normally, that sort of problem is caused by using matrix division (/) instead of element-wise array division (./) however the ‘x...

5 days ago | 0

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Answered
lsqcurvefit - initial condition
The problem with nonlinear parameter estimation is that the results can be highly dependent on the initial parameter estimates. ...

5 days ago | 0

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