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Walter Roberson


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45,383 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
we have license with toolbox in matlab 2015b.is it possible to use the 2015b toolbox in 2018a?
No. You can use an *older* software release with a newer license, but you can never use a newer software release with an olde...

15 hours ago | 0

Answered
Colormap for multline plot
line() colors are not affected by the colormap, ever. They are affected by the axes ColorOrder property. In the release you a...

15 hours ago | 0

Answered
Solving Matrix. Correct code provided. While Loop Error not ending correctly
No it should not be. Your while uses && between the parts. The && operator is only true if both sides are true. With your code a...

15 hours ago | 1

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Answered
help, im getting the following error: error using zeros size input must be scalar
for i=1:1:b j=1:1:d; That code sets j to be a vector. Later you try to use j+1 as the first parameter to zeros(). You ...

15 hours ago | 0

Answered
count function, whwn i enter numbers and its wrong the count isnt going read the commnets i made
Suppose Count has reached 3 and mod(a, 2)==0. The loop will continue. choice will be input. Count will be incremented to 4. 4 is...

17 hours ago | 0

Answered
Error using trustnleqn (line 28)
Part of your expression is ((x(2)/1-x(2))^6)/((x(2)/1-x(2))^2)) The right hand side of that is (x(2)/1 - x(2))^2 which is (x(2...

23 hours ago | 0

Answered
What is the best practice of conditional statements in solving a complicatedly branched system?
Another alternative is to discretize() based upon the pH, with edges at 3.8, 4.3, 4.57, 4.6, and so on. Then for each tempera...

24 hours ago | 0

Answered
Error using @regress fuction
The @ operator can be used in four related syntaxes: @NAME : create handle to function indicated by the name @NAME1.NAME...

1 day ago | 0

Answered
Undefined unary operator '-' for input arguments of type 'function_handle'.
I predict that tau is a function handle and so -tau is trying to use the operator - on the function handle. You cannot do arithm...

1 day ago | 1

Answered
To RESHAPE the number of elements must not change.
vale is 1200 entries. You are trying to reshape it to be an array 1024 by 8. That cannot work.

1 day ago | 1

Answered
row dimension of aeq is inconsistent with length of beq.
beq should be a vector that is the same length as the number of rows in Aeq. Your beq looks like an array the same size as Aeq. ...

1 day ago | 0

Answered
Getting an error Product of known dimensions, 9600, not divisible into total number of elements, 1200 while reshaping. How to solve this issue
You have 1200 elements in vale. nfft is the same. Navg is 8. You are trying to reshape the 1200 elements to be 1200 by 8 by what...

1 day ago | 0

Answered
help for creating a 2D lookup table .
My comment shows how inf can occur for non-infinite values even when examining data inside the region. However, *probably* wh...

1 day ago | 0

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Answered
could anyone help me to solve the issue in the following matrix
P = rand(3,1)*3+45; Q = (50 - P - 1).*rand(3,1) + 1; R = 50 - P - Q; A = [P, Q, R] ; Now circshift row 2 by 1 ri...

1 day ago | 0

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Answered
How to replace the 5 in my vector with decreasing numbers like 5,4,3,2,1
x(3:4,3:5) = reshape(5:-1:0, 2, 3);

1 day ago | 0

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Answered
Error using bar (line 159) X must be same length as Y. Error in Lab3_Q1234 (line 60) bar(x, y);
You preallocate y but not x. If you got the preallocation wrong then the two can end up different sizes. And you *did* get the p...

1 day ago | 0

Answered
keep getting errors on matlab
You need to rewrite a fair bit. In MATLAB, you cannot create an implicit summation with code along the line of for i = 1 : 5 ...

2 days ago | 0

Answered
Error using pdbread (line 78)
kovetz = pdbread(fullfile(choseD,choseK));

2 days ago | 0

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Answered
Can you edit a pcolor plot after generating one?
conv2() your 2d matrix with ones(2,2)/4 and use the option 'valid' on the call. Now access the center element of that matrix and...

2 days ago | 0

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Answered
how to set colormap jet as a hard default in matlab (should stay for all figures even after restarting)
That is not possible in MATLAB. You could potentially set up a default colormap for the current session, and you could put instr...

2 days ago | 1

Answered
My program isn't plotting anything
All of your x are the same, and all of your y are the same. You are drawing a line from a point to itself over and over again. T...

3 days ago | 0

Answered
Genetic algorithm plot diagram display
The *variable* that you create that has the same name as your *function*, is not used after it is assigned to, so the options yo...

3 days ago | 0

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Answered
How to Plot A 3D Ring of any given shape?
Create a reference set of vertices centered around 0, 0, and a description of faces joining them. I suggest using something comp...

3 days ago | 0

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Answered
How to make group of ones more systematic approach?
Before the loop, struct2cell(Ribboned_100) . Then look at the fieldnames() of Ribboned_100, and match those against the names fr...

3 days ago | 1

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Answered
Visualizing 3 dimensional array
Some of the basic ways to graph 4D data (3 independent variables plus one dependent variables) are: slice() isosurface() volu...

3 days ago | 1

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Answered
How to color an image according to orientation of objects?
When you regionprops(), also ask for PixelIdxList . Now, create a matrix orient = zeros(size(BW)); And loop through the stru...

3 days ago | 1

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Answered
Unable to find explicit solution
vpasolve(k==0, 0.5) The starting guess can be anything from about 1e-3 upwards. There are a minimum of 3 different roots of th...

3 days ago | 0

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Answered
Plotting piecewise, data from matrices/vectors
To go straight down, you need to duplicate the x coordinate with the two different y values. stairs() automatically does the co...

3 days ago | 1

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Answered
strjoin, string, remove a single space, while combining variables.
Join one fewer item in Y, and strcat() or + it on to the end. If you absolutely must use only strjoin, then join one fewer item...

3 days ago | 0

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Answered
How can i display image from array element of cell??
for k=1:numel(fileNm) This = fileNm{k} ; if isempty(This) ; continue ; end imshow(This) ; pause(3); ...

4 days ago | 0

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