# Walter Roberson

I do not do free private consulting. If you want to bring my attention to something, send a link to the MATLAB Answers location. I am currently caught up to T0099089; if you are waiting on a reply from me for an older issue, please send me a reminder.

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**Content Feed**

How to use Runge Kutta method to solve state space equation

(4 by 4) * (4 by 1) --> 4 by 1 (4 by 12) * (12 by 1) --> 4 by 1 4 by 1 + 4 by 1 --> 4 x 1 So that calculation sounds plausi...

ongeveer 9 uur ago | 0

display table in command window without { }

No, it is not. However, if you only need that for display purposes, then tt = table({1;2;3;4;5},{'A';'B';'C';'D';''},{9;10;11...

ongeveer 10 uur ago | 0

How to get fzero with 2 variables in array?

I'm trying to solve fzero for each value of x in an array, and I get theis error: Don't Do That. fzero() is defined as only ac...

ongeveer 10 uur ago | 0

Eliminate a component of an equation

V=1/3*pi.*power(r,2)*h;%m^3 If V = something*h then it follows that h = V/something B=sqrt((r^2)+(h^2)); And that definition ...

ongeveer 11 uur ago | 0

how to fix invalid setting for fixed-step size in matlab?

You configured the Simulink solver as being a fixed-step algorithm instead as being variable-step. When you do that, then you ca...

ongeveer 11 uur ago | 0

How to get fzero to work on an array?

I'm trying to solve fzero for each value of x in an array, and I get theis error: Don't Do That. fzero() is defined as only ac...

ongeveer 11 uur ago | 0

How can I plot the graph of three non-linear coupled ODE's vs. time in xy-plane in MATLAB. I want to use x-axis for time while y axis for x(1),x(2),x(3) thanks

tspan = [0 10]; x0 = [0 0.1 0.2]; [t, x] = ode45(@odefun, tspan, x0); plot(t, x); legend({'x(1)', 'x(2)', 'x(3)'}, 'locati...

ongeveer 12 uur ago | 1

| accepted

I have a question: Objective function is undefined at initial point.

You have function loglt = lnlt( b,yy) and a0=b(1:2); a1=b(3:4); b1=b(5:6); c1=b(7:8); pp=b(9:10); w...

ongeveer 14 uur ago | 0

extract/access same fields from multiple structures (it is a nested structure)

temp = [S1; S2; S3; S4; S5; S6; S7; S8; S9]; all_TKE = [temp.TKE]; The above would only work if the structures all have the sa...

ongeveer 18 uur ago | 1

| accepted

Are there Any Restrictions on Latex Markup in Figure Titles?

The \text is the immediate problem. If you use \textrm instead then you get something

ongeveer 18 uur ago | 0

plot system of 5 odes over time using ode45

tspan = [0 0.184]; xinit = [10000, 0, 0.01, 0, 0]; [t, y] = ode45(@odefun, tspan, xinit); plot(t, y); legend({'T', 'Q', 'V...

ongeveer 18 uur ago | 2

Create and dynamically change a continuous tone with user input in MATLAB

See https://www.mathworks.com/help/audio/gs/audio-io-buffering-latency-and-throughput.html In particular, you cannot change t...

ongeveer 23 uur ago | 1

| accepted

<SOS> Unrecognized function or variable 'setOccupancy'.

It needs the Robotic System Toolbox, R2015a or later. That is the same software and release that introduced binaryOccupancyMap,...

1 dag ago | 0

FUNCTION shift of vector's position

Take a copy of what is about to be overwriten. Use array subscripts to move the old data to the new positions. For example A(:...

2 dagen ago | 0

how to create an input window for more than two variables

prompt = {'r1','r2','r3','r4','o2','o2p','o2pp'}; Note that the collected response will be a cell array of character vectors; y...

2 dagen ago | 1

| accepted

How to format scientific notation to have the same power?

table() objects do not support that customization. You would need to switch the items to text

2 dagen ago | 1

Error with ODE solver for Van der pol equation

Your function receives Y but never uses it, and needs x but does not have a source for x. The simplest fix would be to change...

2 dagen ago | 1

| accepted

FFT, Inadequate Frequency precision

You need a longer signal to get that resolution. Twice as many points would get you to 10.275 and you would need more than that ...

2 dagen ago | 0

| accepted

Plot in MATLAB app desinger not working

plot() only draws lines if you supply at least two adjacent finite coordinates in a single call. However you are passing in scal...

2 dagen ago | 0

creating while loop for two different variable

while delta_a > epsilon || delta_a_prime > epsilon

2 dagen ago | 0

Error on a single numeric equation

heaviside not heavyside heaviside will not convert that table of conditions into appropriate heaviside calls. You can write y...

2 dagen ago | 0

Meaning of a code line

! is going to invoke an operating system command. The operating system copy command will be invoked. We can tell by the ..\ t...

2 dagen ago | 0

| accepted

I am getting an error

which gradient The output will likely show you the name of a file that is not provided by Mathworks. You need to rename or ...

3 dagen ago | 0

Error in 'cable_robot/Frame and Cable Assembly/Left-Rear Cable Assembly': Failed to evaluate mask initialization commands.

Left rear cable assembly block contains some initialization code that is intended to control how the block gets drawn. That code...

3 dagen ago | 0

How can I write this code lines faster?

Your code works, but it leaves 0s inside the array because it never assigns to even rows or columns. But the zeros do not matter...

3 dagen ago | 1

| accepted

i am trying to write a MATLAB code to process two different .wav files the first one include a recording for the word “audio” in an approximately 5 seconds length .wav file?

you have to tell audiowrite a file name. You do *not* have to tell it the number of channels. You have to pass the data to be wr...

3 dagen ago | 0

| accepted

How can I use fminunc with a function that has a vector as output?

You cannot do that. You have a multi objective optimization and need to use gamultiobj or similar. You have fundamental quest...

3 dagen ago | 0

| accepted

In pplane8, how to increase the number of parameter boxes from 6 to 8

pplane8 is a third party product. You should not expect Mathworks to enhance it. The last time I looked, pplane8 had some err...

3 dagen ago | 0

Intensity of each pixel frawn on an image

I(p1(2), p1(1):p2(1)) except you should use min and max to ensure that you get increasing order for the column numbers. ...

3 dagen ago | 1

What does this expression means?

In MATLAB, when you assign into an array that does not already exist, then the array is created and the data type that is associ...

3 dagen ago | 1

| accepted