Community Profile # the cyclist

### Alden Scientific

Last seen: Today Active since 2011

Head of Modeling and Statistics at Alden Scientific. Obsessive runner. Professional Interests: Predictive modeling, statistics. (I don't respond to email via author page, but will usually look at a question if you send me a link to it.)

Programming Languages:
Python, R, MATLAB, SQL
Spoken Languages:
English

#### Statistics

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Why is this logical "&&" passing the "if" statement?
Your code suggests that you think if year/4 is checking if year is divisible by 4. But that is not what the syntax is doing. I...

3 days ago | 0

How I can ignore NaN during calculating @std using "retime.
retime(f2,'yearly',@(x)std(x,'omitnan'))

3 days ago | 1

EpsilonSkewNormal no longer available in Fitdist or Distributuion Fitter
I just tried to run pd = fitdist(randn(20,1),"EpsilonSkewNormal") in R2022b, and got Error using fitdist Distribution name '...

4 days ago | 0

I'm new to Matlab and I am having a hard time typing in fractions with variables, the x usually goes to the wrong part. Can someone tell me how to type in these??
You will benefit from watching the free MATLAB Onramp tutorial. -42*x + 1/42 and x/42 + 215/42 % or (x+215)/42

4 days ago | 0

GMM - gaussian mixture as summation of pdf
It will be easier to help when we see the data, but the general idea would be to sum the pdfs of your best_model, weighted by th...

5 days ago | 0

How to efficiently sum values in matrix using indices from a logical statement of a different matrix
%Set up matrix of values A = [0 1 2 3; 1 2 3 4; 2 3 4 5]; %Set up matrix of probabilities B = [0.05 0.02 0.03 0.1...

5 days ago | 0

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Center of gaussian mixed distribution area
I downloaded and looked over the paper. I am also not certain what they mean by the "center" of the mixed gaussian model. But, ...

5 days ago | 1

Finding data in matrice
If M is your data, bigChange = abs(diff(M,1,3)) >= 24;

6 days ago | 1

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How to find mean of cell array
Here is one way: cellfun(@(x)mean(x,3),h,'UniformOutput',false)

6 days ago | 1

How to draw the delta signal in matlab
Do you mean the Dirac delta function? If so, then dirac might help you. Also, if you do mean the Dirac delta, I hope you realiz...

6 days ago | 0

How can i do a Multiple Linear Regression
My advice would be to try to read and understand the example from the documentation page for regress. Better yet, I would use t...

6 days ago | 0

How do I pick selected values in a matrix
You want the fraction of zeros in the array? A = ... [0 0 0 0 0 2 2 2 0 0 2 ...

6 days ago | 0

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What does sc in imagesc stand for?
scaled colors doc imagesc

7 days ago | 0

Good practice in conditional test with categorical variable
The reason you are getting this mlint warning isn't really about the categorical variables at all. It is because you are trying ...

7 days ago | 0

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sqrtm vs chol to produce draws the multivariate normal distribution
A common reason for not having a positive semidefinite correlation matrix is when the pairwise correlations are estimated (or ob...

8 days ago | 1

Truncated answers when querying chatgpt with Matlab
My impression from searching the same topic is that there is an unpublished token limit (which will roughly translate to a chara...

9 days ago | 0

How to extract diagonal elements of multidimensional array ?
rng('default') N = 4; A = rand(N,N,N); A(1:N^2+N+1:end)

10 days ago | 3

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Using histcounts to determine loose data mode
I think that you have a case of the XY problem here. Namely, you are asking about your solution to a particular problem, but I s...

10 days ago | 0

plotting functions over domain
f = @(x,y) (x.^2 + 3*y.^2).*exp(1 - x.^2 - y.^2); % I'm not certain about your notation here x = -1 : 0.05 : 1; y = -1 : 0.0...

10 days ago | 1

I have 2 columns, i want to find the maximum in the second column and then know what value it is next to on the first column
% Pretend data aw = rand(1221,2) + 250; % Max 2nd col in range, with index [maxW,idx] = max(aw(651:1221,2)); % Absorbanc...

11 days ago | 0

Combinations and Matrices?
There just happens to be a very obfuscated way to do this: M = dec2bin(0:2^20-1) - '0'; size(M)

12 days ago | 0

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How does the classification learner app implement k-fold cross validation?
I am most definitely not an expert in this app, but I built a simple model using the default settings, and then exported the fun...

12 days ago | 0

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fit tool with errors in x and y
I am late to seeing this question, but FYI there is a submission to the File Exchange that does linear, univariate Deming regres...

13 days ago | 0

Issues plotting simple bar graph.
The error message is quite clear. Your X values are not unique. Let's look at a simpler example: x = [1 2 2]; y = [3 5 7]; ...

13 days ago | 0

Strategy on how to save data from multiple runs of an experiment where variables changes
There's probably no single best answer here. But if the overall scale of the data is not too large, storing everything in one ta...

15 days ago | 0

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Pie chart with arrows without text coincidence on each other
This is a case where you need to ask yourself, "What is the information I really need to convey to my audience, and what is the ...

15 days ago | 1

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How to transpose every cell in a table?
% If data are in a cell array c = {rand(1,7),rand(1,27)} ctrans = cellfun(@transpose,c,'UniformOutput',false) % If data...

15 days ago | 1

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what is the meaning of this error? how to stop this error?
One reason for getting that error is having text in a line before the function definition. So if your function file looks like t...

15 days ago | 0