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J. Alex Lee


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91 total contributions since 2016

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Answered
Struct to numeric variable
At the risk of having misunderstood: new_var = [structname.fieldname] This would work if you structname is a structure array 4...

environ 12 heures ago | 0

Answered
How can I specify the way components resize automatically in App Designer?
"uigridlayout" was introduced in 2018b, which may be helpful...It allows pretty sophisticated layouts, although it still seems b...

environ 13 heures ago | 0

Answered
How to add the value of the 3 highest elements automatically from a vector?
like this? [~,idx] = maxk(y,3) y(idx) = y(idx) + sx Are x1 and x2 irrelevant to your question?

12 jours ago | 0

Answered
How to map a vector to a colourmap ?
A brute force way would be to interpolate...not sure if there's a better way x = % ... data vector indices = 0:255; xref = ...

16 jours ago | 1

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Answered
Making a square figure with pcolor
Your coordinate grid matrices x and y are not "aligned" with the axes. You can see this if you just do plot3(x,y,zeros(size(x)...

23 jours ago | 0

Answered
Getting Cell location of checkboxes on selection (UITable)
Is it as simple as defining a CellEditCallback?

27 jours ago | 0

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Answered
Is there an automatic way to find the centre of this circularly-symmetric pattern?
This would be not at all efficient and maybe not robust, but you could pose a minimization problem: Find the coordinates (Xc,Yc...

28 jours ago | 0

Answered
How can I create binEdges?
It looks like your problem is not with binning, but the fact that you have NaN's in your data. By the way if you have 2014b or ...

28 jours ago | 0

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Answered
Extracting particular x and y data points from a figure
Thinking in terms of graphs is useful but only takes you so far. The point is how to think about the data and/or functions under...

28 jours ago | 0

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Answered
Help in implementing ode45 in app designer
Static methods don't assume that the app is passed as the first argument, so remove "app" from the arg list methods (Static) ...

environ un mois ago | 0

Answered
Validate and get exact number of characters using the regular expression
Try out_str = regexp(str, '[A-Z]+-[0-9]{2}$', 'match');

environ un mois ago | 1

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Answered
How to initialize a new matrix of the same type as an existing variable?
I am not sure if this works for symbolic type, but you can initialize an array of arbitrary type by specifying the "last" elemen...

environ un mois ago | 0

Answered
How to remove outliers based on datetime
What if you ran statistics on real or integer representations of datetime, using datenum() or something?

environ un mois ago | 0

Answered
lsqcurvefit initial point is always a local minimum, relative first-order optimality is always = 0
I think you have a typo here: F = @(v,cur_data_wave_x) amplitude*(offset + cos(v0(1)*(cur_data_wave_x) + v0(2))); should rathe...

environ un mois ago | 0

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Answered
Applying a for loop to every column in a vector
Agree with KSSV, avoid naming as "max", but in this case it is not causing your problem. Your problem is that "index" should no...

environ un mois ago | 0

Answered
How to choose 5 random rows from an array of 8 rows for 10 times and save the 10 results
if order doesn't matter (6,4,8,7,2 is the same as 4,6,8,7,2) doc nchoosek if order does matter (6,4,8,7,2 is different from 4,...

environ un mois ago | 1

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Answered
solving a second spatial derivative using ode45
This comment is incorrect: % Create a two element vector that holds the derivative equations of u and % v % U(1) is u and U(2...

environ un mois ago | 0

Answered
How to save file on chosen path in app designer?
can you just simplify and use uiputfile()?

environ un mois ago | 0

Answered
Implicit Boundary Value Problem
Ok, so looks like what you are after is solving a DAE that has BCs at more than one boundary. Docs say it is ode15s and ode23t ...

environ un mois ago | 0

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Answered
Select mxm matrix from mxn matrix and solve systems of linear equations
Does this help with first problem: https://www.mathworks.com/help/matlab/ref/nchoosek.html Second problem, maybe make tolerance...

environ un mois ago | 1

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Answered
Reduce time execution in a real time serial data reading
If instead of a loop, you use a timer (https://www.mathworks.com/help/matlab/matlab_prog/use-a-matlab-timer-object.html), you mi...

environ un mois ago | 0

Answered
how to generate text file from generated output
fprintf() accepts as 1st argument a file identifier for a file opened with fopen(). fid = fopen("somefile","w") fprintf(fid,...

environ un mois ago | 0

Answered
App designer: Enable mouse scroll to change value on slider
Take a look at the UIFigure's following properties: WindowScrollWheelFcn WindowKeyPressFcn WindowKeyReleasedFcn If you need ...

environ un mois ago | 0

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Answered
Trying to identify directions of overlapping lines in images, at my wit's end
Have you looked into radon transforms? You might get some "signal" at the 45 and 135 directions for the right image... If these...

environ un mois ago | 1

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Answered
Comparing terms in a character array
If it is truly a "character array" and you want exact matches only, you can use the findstr() command, which will return empty i...

environ 2 mois ago | 0

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Answered
Web app system command
To the question: Also, an other question just came to my mind: what's the best practice to store permanent data and access them...

environ 2 mois ago | 0

Answered
Getting data from the figure in appdesigner
Here's an example where I used the data cursor's update function itself to collect the coordinates and feed directly into your a...

2 mois ago | 1

Answered
reshaping multi dimensional array and central difference method
Based on your example lines, you seem to have the further simplification that your delta x and delta y are uniform (in your exam...

2 mois ago | 1

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Answered
Filter a table based on date (Error using tabular/dotParenReference (line 95) Unrecognized row name '01/00/0000'.)
The second way is almost right, but when you use () on testtable, you are extracting a subtable, rather than the datetime array ...

2 mois ago | 1

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Answered
Using a image variable from one GUI function to another in AppDesigner
Create a property for your app class to hold the image. You appear to be using appdsigner. In appdesigner's code view, on the l...

2 mois ago | 1

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