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the cyclist


3,889 total contributions since 2011

Data scientist at Cohen Veterans Bioscience; Obsessive runner. Professional Interests: Predictive modeling, statistics.

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Answered
Data (.txt) into matrix
This works on the small file I attached here. If the format is not exactly what you have, maybe you can still figure out how to ...

17 hours ago | 0

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Answered
how can I effectively compute expected value by histogram approximation of probability desnsity function
There might be some nuances in the numerical integration, but here is the basic idea. You need to approximate the integral of x ...

21 hours ago | 0

Answered
Switch not recognizing that 0 is greater than -1
Quoting the Tips section of the documentation for switch: "A case_expression cannot include relational operators such as < or >...

1 day ago | 0

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Simplify code with nested if
% A little pretend data, where I only fill in the 4th column with a few months C = cell(5,6); C(:,4) = {'Jan';'Jan';'Dec';'Mar...

1 day ago | 0

Answered
I have problem writing a matlab function
The coefficient (5.1/(4*pi^2)) is multiplying the term you have called x, which is not correct. It might have been easier t...

4 days ago | 1

Answered
combination and their sum
A = [4 2; 5 7; 3 1]; m = size(A,1); output = []; for j = 1:2 output = [output; A(:,j)']; for i = 1:m ...

5 days ago | 1

Answered
Why is the or statement making something true?
You need Overall_max_score==scores(1,3) | Overall_max_score==scores(2,3) <etc> You could do this more concisely as ismember(O...

7 days ago | 0

Answered
Principal Component Analysis - return data (stock market data)
You might want to check out my tutorial-style PCA answer here. I think one helpful way to think about your 262x5 output is that...

7 days ago | 0

Answered
poisson random distributoin with zeros
If you have the Statistics and Machine Learning Toolbox, then BIG = 80000; SMALL = 1000; MEAN = 2400; idx = randsample...

8 days ago | 0

Answered
Speadsheet with all the answers from my loop
output = zeros(n,1); for i=1:n output(i) = length(find(yy(1:numel(yy),1)==i)); end output That will still write the ful...

9 days ago | 0

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Answered
How to make diagonal matrices from a single column
B = zeros(8,2); B(1:2:end,1) = A(1:2:end); B(2:2:end,2) = A(2:2:end);

9 days ago | 0

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Answered
How to specify a number to the specified position in the array?
There's probably not an built-in function that does just that, but it's easy to do it with basic array manipulations. Here is on...

10 days ago | 0

Answered
How to plot outliers from mean
There are three steps: Create an algorithm to define the outliers Identify the points that meet that definition Plot those po...

11 days ago | 0

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Answered
Function with euler not working properly
The images you posted don't show up for me, either. Your code ran for me, and yielded this figure: I think you might have wa...

11 days ago | 0

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Answered
Comparing elements of a vector.
[g(:,2), idx] = unique(R); g(:,1) = T(idx);

13 days ago | 1

Answered
Create lookup table for cell array
Is this what you want? [num2cell(1:9)' Codeword(:)]

13 days ago | 0

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Answered
Check all values in a table if any is "NAN"
This may work for your case tbl = fillmissing(tbl,'constant',1); assuming the NaNs are the only values that count as missing f...

15 days ago | 1

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Answered
Need help creating an matrix that includes probability
There are many ways to generate pseudorandom numbers in MATLAB. Since this sounds like homework, I'll just point you to this doc...

15 days ago | 0

Answered
Plot two arrays as x and y and select the maximum point
The first thing is trivial ... plot(V,M,'.') I don't understand what you mean by "maximize both" or "do it graphically".

15 days ago | 0

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Answered
Computing determinant of matrix A using LU factorization
If I use the lu function from MATLAB (instead of your lufact function), I get the expected result. So, I'd double-check your LU ...

15 days ago | 0

Answered
Invalid expression. Check for missing multiplication operator, missing or unbalanced delimiters, or other syntax error. To construct matrices, use brackets instead of parentheses
I've spotted two errors so far. (1) Where you have 0.5th where you presumably want 0.5*th (2) In that same line, you typo'e...

15 days ago | 0

Answered
convert string to number or array
I'm guessing it's the space that is causing the problem. Run your array through x = regexprep(x,' ',''); first to remove the s...

15 days ago | 1

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Answered
Scatter3: How can I change the size of a particular marker?
This puzzled me for a bit -- until I read the documentation a bit more carefully. For scatter3, the marker size specified is th...

16 days ago | 0

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Answered
Using two vectors to get the third one
This is virtually equivalent to Fangjun's solution. But it uses some intuitive variable names (and comments) to help you underst...

16 days ago | 1

Answered
Index exceeds the number of array elements (5)
You have initialized x and y to be vectors of length 5. But in your for loop, i reaches the value value 5, and then you try to a...

16 days ago | 0

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Answered
Plot function is not working
Your plotting code is trying to select just one element from the t and y vectors. I think you want this instead: plot(t,y) (I...

16 days ago | 0

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Answered
Passing array as an input argument
Is that how you are calling the function, or is it the function header (inside the function file itself)? If that is how you ar...

16 days ago | 0

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Answered
How to draw a star in matlab
There are two places in your code where you wrote 6pi instead of 6*pi Assuming you are using the MATLAB editor, you should s...

17 days ago | 0

Answered
how to solve equation without values
I suggest you read the documentation about simplifying symblic expressions for the Symbolic Math Toolbox.

17 days ago | 0

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