# 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.

**Statistics**

RANK**3**

of 242.406

REPUTATION**51.774**

CONTRIBUTIONS

**0** Questions

**16.495** Answers

ANSWER ACCEPTANCE **
0.00%
**

VOTES RECEIVED**7.054**

RANK**2.693** of 16.989

REPUTATION**549**

AVERAGE RATING**4.70**

CONTRIBUTIONS**5** Files

DOWNLOADS **40**

ALL TIME DOWNLOADS**5118**

CONTRIBUTIONS**0 Posts**

CONTRIBUTIONS**0** Public Channels

AVERAGE RATING

CONTRIBUTIONS**0** Highlights

AVERAGE NO. OF LIKES

**Content Feed**

Help Plotting Diffusion Equation in MatLab

One option is to stack them in the same axes — x = linspace(-200, 200); v = logspace(-2, 2, 10); y = exp(-(x./v(:)).^2); ...

ongeveer 2 uur ago | 0

Impossible to do an indexing

I suspect the problem is with: soleus(stim_Hz) Here, ‘stim_Hz’ must be either logical, or integers greater than 0. There are...

ongeveer 5 uur ago | 0

Converting syms to double

I have no idea what you are actually doing, however converting between symbolic and double is straightforward (if inefficient in...

ongeveer 5 uur ago | 0

how to assign indexes to a function handle?

‘But I want to use a vector "f" insted of a single number to have a vector of "TL" values.’ I cannot run that because there a...

ongeveer 5 uur ago | 1

smoothdata function not working for matrix . any one have ideas to what is going on?

Try this — LD = load('mat.mat'); a = LD.a; for k = 1:size(a,2) a_smoothed(:,k) = smoothdata(a(:,k)); end x = 1:si...

ongeveer 19 uur ago | 0

problem with fit function for data

The fit function requires column vector arguments. Force that sith the ‘(:)’ subscript noitation. E = [416.861, 818.7, 109...

ongeveer 22 uur ago | 0

How to use one marker for looped plots in legend

I cannot run the posted code, however the solution may be straightforward. figure hold on for k = 1:50 hs{1} = scatter...

1 dag ago | 0

fit 2nd order differential equation parameters to data

The problem appears to be not allowing the intial conditions to be estimated as parameters as well as the initial value of ‘a_m’...

1 dag ago | 0

| accepted

Using solve to find intersection points

It’s as simple as it looks — syms x f(x) = exp(-x^2) g(x) = sym(0.8) xi = solve(f == g) xi_vpa = vpa(xi) .

1 dag ago | 0

| accepted

How can I simplify the folllowing equation

One approach — syms x Eqn = 2*x^2 - 2*x*(2*x^2 - 1) + 2*x*(2*x*(2*x^2 - 1) - 2*x^2 + 1) - 1 Eqn = simplify(Eqn, 500) .

2 dagen ago | 0

| accepted

How to plot data with two different X- axis in a single plot?

One option is to use the subplot function in a loop — Z = readtable('https://www.mathworks.com/matlabcentral/answers/uploade...

2 dagen ago | 0

| accepted

translating and solving an equation with values of x and y known

In the third term, the square root is of the numerator only, not the entire expression, amd the denominator does not appear to h...

2 dagen ago | 0

To determine whether the system is stable.

Welcome to the wonderful world of floating-point approximation error! See ‘Check’ and ‘Check_max’ for an illustration of the ...

3 dagen ago | 1

| accepted

How to properly format a data table with fprintf?

In the numeric edit descriptors, the value to the left of the decimal is the field width (this includes all the numbers, the sig...

3 dagen ago | 0

Find which matrix row contains average minimum value

One approach — M = rand(288,365); AMV = mean(min(M)) % Average Minimum Value [val,idx] ...

3 dagen ago | 0

| accepted

trying to find theta

The Question lacks clarity. % plot mountain Mn_x = [0, 1000, 3014.8]; Mn_y = [0, 0, 616]; plot (Mn_x, Mn_y) hol...

3 dagen ago | 0

| accepted

Solve for x given y and plot

Depending on what you wan, either use fzero or interp1 — y = @(x) (2 * exp((2*x)/3)) - ((7*x.*exp((2*x)/3))/3); x = linspace(...

3 dagen ago | 0

| accepted

Doubt in solving ODE45

It seems that ‘dis’ does not appear anywhere. L=20; v=20;%v (m/sec) T=L/v; tspan_1=[0:0.001:T];%time range y0_1=[0;0];...

3 dagen ago | 0

How do you plot a line of constant value on a surface plot?

See if contour3 or contour3m will do what you want. [X,Y,Z] = peaks(30); figure surf(X,Y,Z) hold on contour3(X,Y,Z,[1 1...

3 dagen ago | 0

How to properly create function for integration?

There are several problems with the posted code image. First, ‘z’ is not defined anywhere, and it is not an argument to ‘E_fu...

3 dagen ago | 0

How can I plot the derivatives of the components of the solution to a system of ODEs?

The only way is to use al loop — tspan = [0 50]; z0=[0.01 0.01 0.01 0.01]; [t,z] = ode45(@(t,z) coupled(t,z), tspan, z0); ...

3 dagen ago | 2

| accepted

Cannot calculate integral function

If you want a numeric result, use vpaintegral (introduced in R2016b) instead of int. Not all expressions have analytic integral...

3 dagen ago | 0

| accepted

How to convert logarithmic to linear

If you have the Signal Processing Toolbox, use the db2mag function. If you do not have it: dB2mag = @(dB) 10.^(dB/20); ...

3 dagen ago | 0

Matlab Polar Plot Legend does not match with the plot

I cannot run that and I amm not certain what you are are plotting. Create a handle for each polarplot call: th = linspace(0, ...

4 dagen ago | 0

How to save output of double loop as a matrix?

Since ‘A’ is a matrix, save it as a cell array — for i=1:m for j=1:n A{i,j} = myfunction(...) end end .

4 dagen ago | 1

| accepted

Shaded Standard Deviation Corridors

There are NaN values in ‘x’, ‘y’, and ‘sd’. This ia frequent cause of patch failures. Remove them and it works! Try this ...

4 dagen ago | 1

| accepted

3D Sphere projection in Matlab

I worked on this for a while yesterday, without success. Today, I used a relatively straightforward approach that simply flips ...

4 dagen ago | 1

How would I go about writing this equation in matlabs?

There are several options, depending on what you want to do. syms x p(x) = 1/(2*sqrt(sym(pi)))*exp(-(x-5)^2/4) figure f...

5 dagen ago | 0

| accepted

How to save .mat file into hdf5 in matlab?

I have no recent experience with HDF5 files, however the h5write documentation for data indicates that it must be a numeric matr...

5 dagen ago | 0

Error with plotting my function

It works if you give ‘f’ a vector to work with — f = @(x) 2.^x-5*x+2; %Given Function xaxis = [0:0.5:2]; ...

5 dagen ago | 2

| accepted