Community Profile # Star Strider

Last seen: Today 2012 以来アクティブ

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

All
• • • • • • • • • • • • バッジを表示

#### Content Feed

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...

26分 前 | 0

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,...

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)...

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) ...

| 採用済み

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...

| 採用済み

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

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 ...

| 採用済み

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,...

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日 前 | 1

| 採用済み

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日 前 | 0

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日 前 | 0

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日 前 | 0

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日 前 | 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 ...

2日 前 | 0

| 採用済み

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

2日 前 | 0

| 採用済み

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. ...

2日 前 | 2

| 採用済み

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

3日 前 | 1

| 採用済み

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日 前 | 0

| 採用済み

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日 前 | 1

| 採用済み

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日 前 | 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) ...

3日 前 | 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.

3日 前 | 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 ...

4日 前 | 0

| 採用済み

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日 前 | 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...

4日 前 | 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...

4日 前 | 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...

4日 前 | 0

| 採用済み

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

4日 前 | 0

| 採用済み

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 ...

5日 前 | 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; ...

5日 前 | 0

| 採用済み