J. Alex Lee

Last seen: Today

223 total contributions since 2016

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Answered
Grouping age data into 5 year bins
Interesting, this could be useful for me too! You can use "discretize" to bin the data. Below is a quick and dirty class to impl...

7 jours ago | 0

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How to vectorize the following code for matrix insertion?
There is a minor point in David's answer, which is that not all index collisions are taken care of in how the g matrix is constr...

7 jours ago | 1

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How to rotate 3D matrix?
it looks like your segment A is parallel to the axis OA (trivial in y-direction), in which case it should be easy to first trans...

7 jours ago | 0

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1-D Temperature Gradient
your time and space point vectors are t = 0:0.005:50; % but this gives you 10,001 points, not 10,000...so you decide what you h...

11 jours ago | 0

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how to find the order of convergence
It sounds like you already implemented Newton's method, so just save all your residuals and plot [the log of norm] versus the pr...

14 jours ago | 0

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Saving each vector of an ode45 vector solution in a matrix.
Use a cell array instead z = cell(1,20) for i=1:20 G=i/20 %Saving that iterates value of G [phi,y]=ode45(@(phi,y) od...

22 jours ago | 0

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How can I generate values randomly from another existing vecor?
how about v1 = [122,34,20,5,21] v1a = [0,v1] N = numel(v1a) ridx = randi(N,size(v1)) v2 = v1a(ridx)

22 jours ago | 1

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Probelm with web app server
@Martin Andersson, hope you have resolved this by now as it has been over a month, but if not, check your windows service accoun...

27 jours ago | 0

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How to find duplicate file names(same name but different folder address), and write those files in excel with their respective folder address?
Here's a way that doesn't require as many loops and calls to ismember % % uncomment to simulate the results of dir and test % ...

environ 2 mois ago | 0

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Get all allowed values of a class property
Ah, I should more fully embrace the validator mechanism. Here is a way by defining a custom validator, so in a way less hard-cod...

environ 2 mois ago | 2

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web() and inputdlg() in App Designer
i think you can get around both limitations with some extra coding...never tried it, and just a thought, but... you could proba...

3 mois ago | 0

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Want to connect 3D scattered data points with line
On way is to do it in a loop. After your code, hold on d = zeros(size(x)); % to hold distances from the first point for i =...

3 mois ago | 1

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Concentric Squares with matricies
Try looking into padarray (or arraypad I can't remember...). I think you can apply successively to achieve what you want

3 mois ago | 0

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Storing a loop index value in a dynamic array?
Without trying to get into the weeds of your need, did you know that "unique" can additionally output indices into each argument...

3 mois ago | 1

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Extract data from a timetable excluding an specific date
This should work. Most of these steps should be straightforward..."ismember" may have been the key tt_1 = timetable(datetime({'...

3 mois ago | 0

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Save plot as logical matrix array with same dimensions as original?
are you looking for imwrite()? or some combination of getframe(), frame2im(), and imwrite()?

3 mois ago | 0

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multiple isntances of custom ChartContainer in a figure
Oops, documentation says that the Parent of an instance of chartcontainer can only be one of Figure object (default) | Panel ob...

3 mois ago | 0

Question

multiple isntances of custom ChartContainer in a figure
I defined a custom matlab.graphics.chartcontainer.ChartContainer class. When trying to populate a uigridlayout with multiple in...

3 mois ago | 1 answer | 0

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Copy and re-arrange data from one column into another
Is this what you are looking for? load("~/Downloads/Sample_table_MatLab.mat") a = ["CG", "CG_LOW", "CG_HGH", "MLD", "MLD_LOW...

4 mois ago | 0

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plot 2 different time data on the same axis in same graph
To overcome the merged legend issue, you can create an empty plot to make the legend entry T = readtable('TIMEDATA.txt'); fi...

4 mois ago | 0

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plot 2 different time data on the same axis in same graph
or potentially you are just looking for "hold on"

4 mois ago | 0

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Calculating number of elements of a vector greater or equal than elements of other vector
R = rand(1,10000); losses = sort(rand(1,2000)); for i = numel(losses):-1:1 counts(i) = sum(R >= losses(i)) end

4 mois ago | 1

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Discrepancy with easy ODE.
You have a syntax error on what your odefun is returning. To fix: function [yp]=fun(t,y) yp=y*(1-y); end

4 mois ago | 0

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Creating iteration to make CSVs that do not overwrite
I agree with Ive J and their solution will work, but if N>9, you may want to include leading zeros. I'm not sure how to do that ...

4 mois ago | 1

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Solve differential equation system with ode45
If you want to use ode45, then you have to pose as 5 first order ODEs in place of the 3 you have, by defining new variables J=G'...

5 mois ago | 0

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Solving complicated system of symbolic equations
I like John's comment about visualizing. To expand on this, and Walter's comment that it is trickier to do this in the complex p...

5 mois ago | 0

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Select random numbers from matrix without repetition
And here is a different approach to the contiguous blocks. Instead of checking for overlaps, you can avoid them by tagging eleme...

5 mois ago | 0

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Select random numbers from matrix without repetition
Here is a simple way if you don't need contiguous blocks, but just need to randomly sample elements without repeating L = 1024;...

5 mois ago | 0

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readtable (excel) behavior for string type with empty cell vs spaces
According to Jemima's answer, confirmed that the issue is an internal conversion of the "" to <missing> within readtable. Furthe...

5 mois ago | 0

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Split datetime column data into two column
if you import it as a datetime variable, you can use datetime operations to render into whatever format you want, including one ...

5 mois ago | 0