# 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

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**Content Feed**

Output additional vectors from ode45

Adding additional outputs is permitted, providing that they are not used in the ode45 call. Normally, this is not a problem, be...

etwa 9 Stunden ago | 1

| accepted

Why getting NaN's and other garbage from interp1?

I am not certain what the problem is (providing the data without the code and interp1 calls is not informative), however unless ...

etwa 13 Stunden ago | 0

| accepted

How to measure the angle between the poles and the x-axis using the Root Locus?

The x-axis is the real axis, so the angles (in radians) sould be given by the angle function — sys = tf([2 5 1],[1 2 3]); [r...

etwa 14 Stunden ago | 0

Vectors must be the same length

The number of elements in ‘Y1’ in the plot need to be the same as the number in ‘x’ so one way would be to re-define ‘x’ to be t...

etwa 21 Stunden ago | 0

| accepted

Problem with AlphaData property

The FaceAlpha (transparency) value is set to 'interp' and it is doing exactly what it is told to do! It will likely be necess...

etwa 21 Stunden ago | 0

system of differential equations

Use the Symbolic Math Toolbox if available. Those all appear to have analytic solutions, since they all appear to be linear. S...

etwa 21 Stunden ago | 0

Number of line for fcontour

A somewhat different approach — syms x y z(x,y) = exp(-(x-5)^2) + cos(y) figure hfc = fcontour(z, [0 10 -2*pi 2*pi]);...

ein Tag ago | 0

| accepted

ho to find index at which the 50% of the sum vector is included?

A least-squared-difference approach works — a=[3 5 7 3 5 8 9 3 1 41 6]; suma = cumsum(a); suma50 = suma(end)/2; [minv,idxv]...

ein Tag ago | 1

How can I skip the first to lines from a text file and proceed to read the file with header lines in between the values?

Try this — C1 = readcell('https://www.mathworks.com/matlabcentral/answers/uploaded_files/814274/BSH_HBM_tracer_productgrid_f...

2 Tage ago | 0

How to activate the low-pass filter on NI-6115?

It will likely be best to Contact Support for this. I did an online search and could find no previous posts regarding the NI-61...

2 Tage ago | 0

| accepted

Function value and YDATA sizes are not equal. Can anyone help?

The problem is the randn call. With one argument, it creates an (nxn) matrix, not a vector, so of course the sizes will not mat...

2 Tage ago | 1

Error with the division

Use the table2array function to convert the contents of the table to an array. Assign the arrays to new variables rather than o...

2 Tage ago | 0

error [empty sym] using dsolve "Warning: unable to find symbolic solution"

It is likely not possible to derive a closed-form (analytic or symbolic) solution for those. Create an anonymous function to us...

2 Tage ago | 0

How to define values in a vector as NaN ?

Try this (using ismember) — A = [1 2 3; 4 5 6]; B = [2 3; 5 6]; C = ismember(A,B) A(C) = NaN .

2 Tage ago | 1

| accepted

Define an additional variable in ODE solver

This is all a bit confusing, since the differential equations are not them selves functions of ‘C1’ and ‘C2’, so a differential ...

2 Tage ago | 0

| accepted

Can't Uninstall, What Should I Do?

Option #1: Contact Support The uninstall function deletes registry entries as well, however a fresh install should over-write...

3 Tage ago | 0

symbolic variables into double array, observability matrix

The variable values need to be provided in order to use the Control System Toolbox funcitons. To do this symbolically, create...

3 Tage ago | 0

Question in continuous time signals

Everything in a computer are discrete, not continuous (except the voltages on the chips themselves and the outputs of a soundcar...

3 Tage ago | 0

How to solve the implicit equation

First, a multiplication operator (my best guess, anyway) is missing: ((alfa*Vt*Vmpp*(2*Impp-Isc))/((Vmpp*Isc+Voc*(Impp-Isc))*(...

3 Tage ago | 0

How can we combine the two figures?

‘When you execute the code below, two plots are drawn.’ No, not without knowing what the variables are. However the prob...

3 Tage ago | 0

Calculate this matrix in a more general and shorter way

Yes, actually. However since it appears that the objective is to do a Fourier transform, I would set it up a bit differently ...

3 Tage ago | 0

ODE45/ODE15 inquiry about nonlinear spring

Since the system appears to describe a differential-algebraic equation, see the documentation section on Solve Differential Alge...

3 Tage ago | 0

Symbiological output using 'syms' and 'pretty' commands

Experiment with the indexing into the expressions (since this is a straightforward solution to a number of otherwise difficult p...

3 Tage ago | 0

How do I reflex a plot?

Try this — u = -8:1:1.3; v = -pi:pi/10:pi; for k = 1:numel(v) x{k,1} = 1 + u + exp(u)*cos(v(k)); y{k,1} = v(k) +...

4 Tage ago | 0

how to increase function values through its derivetive

Do some simple experiments to see what produces the desired result — syms k x dx1 = 2*x; ...

4 Tage ago | 0

Problem to solve integration

Change this — f = @x sin(x); to this — f = @(x) sin(x); That should work. .

4 Tage ago | 0

Removing a particular legend from plot

The first two lines have the same line style. To see them individually, choose a different line style for each. To label t...

4 Tage ago | 0

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how to solve the following equation?

Try this — a=[1,2,3]; afcn = @(b) ((b-2).*(b+1))./((b+3).*(b-1)); [estb,fval] = fminsearch(@(b) norm(afcn(b) - a), rand) ...

4 Tage ago | 0

| accepted

How to plot 3D filled contour ?

It would help to know the data and the desired result. One option is to use the surf function and contour3 — [X,Y,Z] = peak...

4 Tage ago | 0

Using ode45 for a non linear differential equation with a term in a vector form

I do not understand the problem. Is the objective to estimate a parameters of the differential equation from data? The tim...

4 Tage ago | 0

| accepted