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Walter Roberson


Last seen: Today |  Aktiv seit 2011

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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 T0099119; if you are waiting on a reply from me for an older issue, please send me a reminder.

Programming Languages:
C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English

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Beantwortet
How to determine how many random numbers were generated, using Mersenne twister?
Record the two rng states. Loop generating one number at a time from each of the two streams until the newly generated state of ...

etwa 12 Stunden vor | 0

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Beantwortet
String Comparisons in Tables
if strcmp(ImportDataGeom(i,1),"CircleR"+i) When you use () indexing of a table, the result is a table. Use {} instead.

etwa 12 Stunden vor | 1

Beantwortet
Int() returning incorrect answer
Especially in the case of trig expressions or expressions that integrate to trig (such as ones that integrate to arctan), then i...

etwa 12 Stunden vor | 0

| akzeptiert

Beantwortet
Can't open simscape electrical example in command window
That example is new as of R2021b, the release after the one you have. Note: the url details changed as of r2022b; the previou...

etwa 12 Stunden vor | 0

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Beantwortet
error message: integral calculation
p = (abs(integral(@(z) fun,0,Ls)))^2/Le%ρ @(z)fun is an anonymous function that ignores its input argument and returns the a...

etwa 19 Stunden vor | 0

Beantwortet
Array indices must be positive integers or logical values.
for ii=1:J+1 Sr = 7.5 + 0.001*(1+sin(X*ii)); Sl = 7.5 + 0.001*(1+sin(X*ii)); Ir = 0.0 + 0.001*(1+si...

etwa 19 Stunden vor | 0

Beantwortet
Which Matlab product service install for electrical engineering students?
For Electrical Engineering work, Simulink especially with Simscape Electrical are often used. Filtering signals is quite common...

ein Tag vor | 1

Beantwortet
'for' loops in app designer methods have a parsing problem
It is a language limitation. for has never supported any kind of indexing for the loop control variable. The limitation saves de...

ein Tag vor | 1

| akzeptiert

Beantwortet
Hello Matlab Community, Can someone write sum loop for me as menstion in the image and how to use subscript 1 with Q..
A = rand(1,20); B = rand(1,20); X = A./B; %looped sum total_looped = 0; for Index = 1 : numel(X) total_looped = total...

ein Tag vor | 0

Beantwortet
Display a cell in an fprintf?
You can use celldisp to display a cell, but the result is somewhat verbose, not a nice format. What you would normally do with ...

ein Tag vor | 0

Beantwortet
how to make matrix
F = zeros(20,1); F(1:4) = 3.3; F(5:7) = 4.2; F(8:10) = 1.8; F(11:13) = 6.9; F(14:17) = 4.3; F(18:20) = 4.1; table(F) ...

ein Tag vor | 0

Beantwortet
How to find the mean for each specified range in a table without writing multiple lines of the same code?
Like I told you before, use groupsummary (see also findgroups )

ein Tag vor | 0

Beantwortet
Trying to use fsolve works over lower part of range (values < 10) but fails in upper part of range (values > 10)
Vbfcn = @(Ca,Cb,Ka,Kb,Kw,Va,H) Va.*((Ca./(1+H./Ka) - H + Kw./H) ./ (Cb./(1+Kw./(H*Kb)) + H - Kw./H)); In the line above, I do...

ein Tag vor | 0

Beantwortet
Debugging a sequence of anonymous functions
"I have to use the anonymous functions as is. I was just wondering if there's a easy way to debug them" No, there is not. You c...

ein Tag vor | 0

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Beantwortet
Can we manipulate a file without opening it
I suggest that you switch to using parfeval() . Approximately while you haven't gotten tired of it all while number of act...

ein Tag vor | 0

Beantwortet
Thunderstorm Summary Matlab Solution
The figure below shows That is not a question. You can analyze this data That is not a question. You will use the groupsumma...

ein Tag vor | 0

Beantwortet
How can i use any variable once for initialization and then the variable is updated and should be replaced with new value? I tried one way, but it isn't working
persistent V iter_count if isempty(V) V = [1.0000 0.9159 0.9139 0.9133 0.9965 0.9929 0.9922 0.9916 0.9794 ...

ein Tag vor | 0

Beantwortet
How to extract certain cells from one column based on the information in another column using data from imported file?
mask = Book1.Year == 2016 & Book1.Province == "QC"; subset = Book1(mask,:); See also splitapply and groupsummary

ein Tag vor | 0

Beantwortet
I'm trying to plot the results of the while loop but the graph is showing gup blank, can someone show me what I'm doing wrong? Thanks!
t = 0; vv = 0; Those are scalars t = acosd(1-(((m1*vv)^2)/(2*m2^2*g*L))); vv is a scalar, and probably m1 and m2 and g ...

2 Tage vor | 0

Beantwortet
How to find an array with all common elements?
a= [1 1 1 0 1]; b= [1 0 1 1 0]; a(a == b)

2 Tage vor | 0

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Beantwortet
Given time series and sample frequency, how do i conduct Fourier transform onto this time series and determine amplitude, frequency and phase?
If you have a signal that is sampled at regular time intervals, then use fft and see the first example there for the code to fig...

2 Tage vor | 0

Beantwortet
What is the MATLAB code for Modified Duobinary coder without a pre-coder?
There is no function provided in MATLAB or any of the toolboxes for that purpose. You will need to write the code yourself, or...

2 Tage vor | 0

Beantwortet
I want to ask if it is possible to add these two horizontal matrices and if so, how?
No, it is not possible. The first one is 5 x 3 and the second is 10 x 1. You can extract the first 5 rows of S and add that to...

2 Tage vor | 0

Beantwortet
Extracting numbers including 0 at the start of the number
The way numbers like 02290234567 are stored internally is as IEEE 754 Binary Double Precision. It is a base 2 representation, an...

2 Tage vor | 0

Beantwortet
Trying to fix output from matlab code for derivative
remove df = [NaN NaN derivative NaN NaN]; but leave the assignment of nan to df Now offset = floor((numel(f) -...

2 Tage vor | 0

Beantwortet
save 3D figure obtained with 'findobj'
savefit(fig_4, fullfile(destdirectory_FIG, 'name_of_FIG.fig'))

3 Tage vor | 0

Beantwortet
Reference to non-existent field when opening gui with toolbar icone
If you have created a gui using GUIDE then you must run the m file not open the fig file. The handles structure does not get cre...

3 Tage vor | 0

Beantwortet
Double integral with variable limit with integrand as an numerical array
Use integral2(). The first set of bounds must be numeric, but the second set of bounds can be function handles.

3 Tage vor | 0

Beantwortet
How to give colorbar to a tif image in Matlab
If the tif is rgb then there is no meaningful colorbar for it. If the tif is not rgb then imshow would have automatically use...

3 Tage vor | 0

Beantwortet
parfor with temporary variable worning
temp_info is assigned to inside the parfor in a way that is not indexed by the loop variable. parfor automatically makes it a te...

3 Tage vor | 0

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