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Walter Roberson


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47.310 total contributions since 2011

I do not do free private consulting. If you want to bring my attention to something, send a link to the MATLAB Answers location.

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Answered
Deleting within .mat file
A work-around that is sometimes good enough is to create the variable locally with empty contents, and save with the -append fla...

circa un'ora ago | 0

Answered
What is the unit in Legend of Colormap
It is not what matlab would generally call a legend: matlab would call it tick marks or tick labels. There is no unit associa...

circa 3 ore ago | 1

Answered
Transferring variable names from one table to another
varnames = DataFinal.Properties.VariableNames T = table('VariableNames',varnames, 'RowNames', {'A','B','C'})

circa 4 ore ago | 0

Answered
How to supress the File Overwrite pop-up when using rfwrite()
create private/questdlg.m function str = questdlg(varargin) str = 'Yes' You might have to get more creative such as...

circa 5 ore ago | 0

Answered
Divide a 3D matrix into smaller 3D matrixes
YourCell = mat2cell(size(YourArray,1), size(YourArray,2), 4*ones(size(YourArray,3)/4));

circa 15 ore ago | 0

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Answered
i am getting an error "Index exceeds the number of array elements (2).", please can someone correct it. thanks in advance
d=(poissrnd(r,L,N,L))/1000; d is fairly likely to have entries that are 0. B=10.^(-13.9 - 3.5*log(d) + 0.8*randn(L,N,L)); Tho...

circa 15 ore ago | 2

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Answered
How to get the x,z coordinates for a specific y value out of my 3d surf plot?
sh = findobj(gcf, 'type', 'surface'); if isempty(sh) error('No surface found') end sh = sh(1); %in case there were ext...

circa 16 ore ago | 0

Answered
Problem regarding fmincon solver
lb = [0.0;0.0;0.0;2.0;1.0]; ub = [4.0;4.0;3.0;4.0;12.0]; x0 = [0.0,0.0,0.0,0.0,0.0]; lb is lower bounds. Your second-last ent...

circa 17 ore ago | 0

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Answered
Incorrect use of '=' operator. To assign a value to a variable, use '='. To compare values for equality, use '=='.
RL2 = (RL/2; That is an incomplete expression that would cause problems for what follows.

circa 17 ore ago | 0

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Answered
GUIDE Handle not updating
handles.Antena.Info = readAntenna(selected,currDir); If handles.Antena is a scalar struct then that statement assigns to handle...

circa 17 ore ago | 0

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Answered
I need help solving a system of differential equations. The equations are given below, in matrix form. The problem that I'm having is regarding the fact that I have time dependant elements in the matrices.
Rs = 1; %systemic resistance Rm = 0.005; %mitral valve resistance Ra = 0.001; %aortic valve resistance Rc = 0.0398; %chracter...

circa 18 ore ago | 0

Answered
Capture I2S data from FPGA board to MATLAB or Simulink
SoC Blockset Support Package for Xilinx Devices has https://www.mathworks.com/help/soc/ref/i2cmaster.html If I read specifica...

circa 19 ore ago | 0

Answered
How do I derive a parametric slope symbolically?
I wanted to know if Matlab is able to take the argument diff(y,x) given that x and y are functions of t, and derive and then out...

circa 20 ore ago | 0

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Answered
How do I name a structure or matrix with variable names (without using eval)
put everything into one variable. You can use dynamic field names for a struct, new fields added as you go. Or you can hold ever...

circa 21 ore ago | 0

Answered
How to solve transcendental equation?
f(x) == c implies that f(x) - c = 0. You can construct the expression f(x)-c and use it with a root-finding function such as fso...

circa 21 ore ago | 0

Answered
Error on uninstalling matlab
You can create that and then proceed so that it will exist to be removed. However, past experience shows that a bunch more such ...

circa 24 ore ago | 0

Answered
Drawing a line without creating a legend entry
https://www.mathworks.com/matlabcentral/answers/25381-how-to-show-partial-legend-in-figure#answer_33306 You can set the IconDi...

1 giorno ago | 1

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Answered
How to use 'fmincon' in hardware through simulink without any code generation error?
Generally speaking, Simulink Coder does not support matlab functions that you need Coder.extrinsic for. MATLAB Coder does suppo...

1 giorno ago | 0

Answered
Failed to read xml error when using xmlread
filename = 'InputFileName.xml'; S = fileread(filename); SS = regexprep(S, 'encoding="ISO8859-', 'encoding="ISO-8859-', 'once')...

1 giorno ago | 0

Answered
Vectorization of For loop
d = sum(b .* reshape(a, 1, 100, 100), [2 3]);

1 giorno ago | 0

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Answered
Plotting a set of rings using a single function
r = 50; viscircles([0 0; 0 2*r; 2*r 0; 2*r 2*r], [r;r;r;r], 'color','k', 'linewidth', 1) If you need to be able to plot fewer ...

1 giorno ago | 0

Answered
Help with Summation in Matlab
My guess: x_k = sum(diff(t_j(1:k)) .* V_xj(1:k-1) + x_1); but the x_1 does not make sense to me in that location: why would yo...

1 giorno ago | 1

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Answered
Simplify Boolean/logical expression
simplify(S, 'steps', 10)

1 giorno ago | 2

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Answered
Return a figures from different functions and subplot them
Your function returns the line handes. If you record them, then you can take each handle and set its Parent property to be the a...

1 giorno ago | 0

Answered
Scattered data 4D interpolation
What interpolation do you need? For example you could do knnsearch() asking for the 2 nearest neighbours of each query point, ...

1 giorno ago | 0

Answered
real clock seconds after 1 second delay in input
If you do not need high precision on it being every 1.0 seconds elapsed, then: max = 15; input = [0 0 0 0 1 1 1 0 0 0 1 1 1 1...

1 giorno ago | 0

| accepted

Answered
How to extract RGB matrices from stacked TIFF file?
squeeze(mean(YourArray, [1 2])) squeeze(std(YourArray, [], [1 2])) These should give you a 3 x N array of values that are the ...

1 giorno ago | 0

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Answered
can calculate mean but not std
You accidentally created a variable named std

1 giorno ago | 1

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