# 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)

**Statistics**

RANK**3**

of 265.367

REPUTATION**58.872**

CONTRIBUTIONS

**0** Questions

**18.279** Answers

ANSWER ACCEPTANCE **
0.00%
**

VOTES RECEIVED**8.136**

RANK**2.629** of 18.133

REPUTATION**592**

AVERAGE RATING**4.70**

CONTRIBUTIONS**5** Files

DOWNLOADS **24**

ALL TIME DOWNLOADS**5548**

CONTRIBUTIONS**0 Posts**

CONTRIBUTIONS**0** Public Channels

AVERAGE RATING

CONTRIBUTIONS**0** Highlights

AVERAGE NO. OF LIKES

**Content Feed**

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...

ongeveer 3 uur ago | 0

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 ...

ongeveer 4 uur ago | 0

MATLAB is not displaying my numbers as what they should be.

Use the format function to display the data as you want them.

ongeveer 7 uur ago | 0

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. ...

ongeveer 9 uur ago | 1

Could not recognize the format of the date/time text

The days and months are ambiguous, likely the reason datetime had problems with them. Change the 'MM' and 'dd' positions as n...

ongeveer 19 uur ago | 0

Creating a log probability plot for particle size distribution

See the Statistics and Machine Learning Toolbox probplot function.

ongeveer 21 uur ago | 1

| accepted

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 ...

1 dag ago | 0

| accepted

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...

1 dag ago | 0

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(...

1 dag ago | 1

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) ...

1 dag ago | 0

Does MATLAB have inverse tangent integral TI2(z)?

The polylog function exists in the Symbolic Math Toolbox. It supports symbolic and numeric (double) arguments.

1 dag ago | 0

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 ...

2 dagen ago | 0

| accepted

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.

2 dagen ago | 0

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...

2 dagen ago | 0

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...

2 dagen ago | 0

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...

2 dagen ago | 0

| accepted

lsqcurvefit - initial condition

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

2 dagen ago | 0

| accepted

Want to create a time vector

I have no idea what you want to do, although the linspace function may be a more precise approach — t = -10:0.01:10-0.01 ...

3 dagen ago | 0

Why am I not getting the m array?

That clears up much. Plotting them is simply this — %% data X=[6,7,10,14,13,9]; Y=[12,9,7,8,10,14]; xi=10; yi=10; ...

3 dagen ago | 0

| accepted

[SOLVED] Semi-colon not supressing output

I do not see any missing semicolons in the file, so the most likely problem is that there is one missing when you call the funct...

3 dagen ago | 0

| accepted

How to Save Multiple Figures in Loop?

Perhaps this instead — saveas(gcf, sprintf('File%02d_6.tiff',i), '-dtiff'); Specifing the numeric field as '%02d' creates a t...

3 dagen ago | 0

| accepted

Sum, then filter, then re-separate data

It would help to have the sampling frequency. I am not certain what you want to filter, however for now I am assuming that is...

4 dagen ago | 0

| accepted

Audio Pitch Manipulation Through Time

I am not certain what you want to do. One option could be the resample: function.

4 dagen ago | 0

| accepted

How to create a vertical offset line

Try something like this — zv = sort(rand(4,1)) % Define 'z' Val...

4 dagen ago | 0

| accepted

Define time axis interval for 100 samples

I am not certain what you want to plot. Perhaps — % sampling frequency (fs) is 6000 Hz fs1 = 6000; % I want to take 100 s...

4 dagen ago | 0

| accepted

Time + Acceleration Fourier transform into Amplitude + Frequency

The ‘Time’ values are not unique (they likely need an additional digit of precision) so they had to be processed by taking the m...

4 dagen ago | 0

| accepted

create a function from temperature data

Another option: Curve fitting to a sinusoidal function

5 dagen ago | 0

Find the position of numbers in array

I am not certain what you are asking. Perhaps using the ismember (or ismembertol) function will do what you want.

5 dagen ago | 0

How to remove the AWGN noise from data?

I would simply use a moving average filter, for example movmean, or choose one of the options in smoothdata, to eliminate normal...

5 dagen ago | 0

Numeric array to serial datetime

Perhaps something like this — Feed{:,1} = datetime('29-Sep-2022'); Feed{:,2} = '14.45'; DT = Feed{:,1} + timeofday(datetime(...

5 dagen ago | 0