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Jeff Miller

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369 total contributions since 2013

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fitgmdist for loop; nested for loop, combine array of different sizes
I don't really follow what you are trying to do, but maybe some of these comments will help a bit: I. Use a cell array to outpu...

alrededor de 3 horas ago | 0

How do I fit multiple Gaussians to my data?
From the new graph you've posted, it looks like the values in AbsY are not the type of data expected by fitgmdist, and I suspect...

1 día ago | 1

How to compare appropriateness of fitted Weibull and lognormal models via the likelihood ratio test
Unfortunately the likelihood ratio test cannot be used this way. It is only for comparing nested models (i.e., one model has to...

1 día ago | 0

how can i check the geometric distribution
Look at the Wikipedia page on this distribution and it will tell you how to estimate the parameter from your observations (it de...

2 días ago | 0

Use 'trandn' function to draw random numbers from a lognormal distribution
An easy way to get random numbers from a lognormal distribution is to get random numbers from a normal distribution and then exp...

2 días ago | 0

Ploting the result of a fitgmdist (of 1D data)
Say you want to plot the distribution from -15 to 15 in steps of 0.05. This would be the code: z = (-15:0.05:15)'; % Note th...

2 días ago | 0

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Ranking Variables by Value
You might find the second output of the sort command useful. E.g. fruitVals = [p_a p_b p_o p_p]; [~, idxOrder] = sort(fruitVa...

2 días ago | 0

help random numbers generator
Good. Here it is as an 'official' answer: pd = makedist('Normal'); t = truncate(pd,-0.5,0.5); r = random(t,10,1);

4 días ago | 0

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How to generate random numbers from a scaled beta PDF?
Generate regular beta random numbers and then rescale them. I guess you want to generate randomly from the regular beta(3,3) di...

5 días ago | 0

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Why does stepwiselm function output NaN with model interactions?
Multivariate techniques like stepwise regression require more cases (rows) than variables--in practice, you need at least 5-10 t...

5 días ago | 0

Concatenate string to string array in efficient way
strMsgArray = strcat(strStart,strMsgArray,strEnd)

9 días ago | 0

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question related to Statistics in matlab
r=poissrnd(9,200,1); will give you 200 random numbers from a poisson distribution with lambda=9. Lots of those numbers will be...

14 días ago | 0

Calculate Convolution 2 pdf random variables
The built-in conv function is for something else, not statistical convolutions. In general, the probability density function of...

14 días ago | 0

How to do an unpaired t-test?
I'm guessing you have some kind of numerical score in each of 120 trials for each of (say) 30 subjects and you want to know if t...

18 días ago | 0

Overall fir of binomial general linear model
People don't normally test the overall significance of these models. Instead, they look at the significance of the individual p...

21 días ago | 1

Bootstrap alternative to t-test dependent measures does not produce same p values
The p values are not that far off, given that the t-test is based on the assumption of normally distributed difference scores an...

24 días ago | 0

pdf of two distribution in mixture
the pdf of the mixture is just the weighted average of the pdfs of the beta and gamma, something like p_beta = 0.8; % probabil...

25 días ago | 0

Convolution and tolerances: how do I calculate the probability density function of the difference between two dimensions? (mechanical engieering)
In general, if h(x) and s(x) are the PDFs of the hole and shaft, respectively, then the PDF d(x) of the difference d=h-s is d(x...

25 días ago | 1

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How to generate mixture of exponential and beta distribution
Check whether I have interpreted your parameters correctly, but it should look something like this: lambda = 0.5; a = 4; b = ...

26 días ago | 0

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Different functions with different variables as input
I think you can do this by bundling up the arguments for each function in a cell array. It would look something like this (unte...

alrededor de 1 mes ago | 0

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How to compute lower tail probability for the Bivariate Normal Distribution
The function 'mvncdf' computes the lower tail probability for the multivariate normal distribution.

alrededor de 1 mes ago | 0

Question

Can I call integralCalc directly to bypass integralParseArgs?
I'm trying to speed up a function Foo that calls 'integral' thousands of time. The profile viewer reveals that more than half of...

alrededor de 1 mes ago | 1 answer | 0

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How to use original n-th moments formula to calculate mean, skewness and kurtosis in uniform distribution?
I don't think mean(x) gives you what you want inside fun. Try this: fun = @(x,n) (x-0.5).^n;

alrededor de 1 mes ago | 0

What statistical test is available in matlab for unbalanced samples other than ttest?
One possibility is the Wilcoxon rank sum test.

alrededor de 1 mes ago | 1

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How can I generate integer random variables by using exponentially distributed with a mean of 20 seconds?
If you just want integers, then use the geometric distribution instead of the exponential: r2 = geornd(1/mu2,sz1,sz2);

alrededor de 1 mes ago | 0

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Negative correlation between two random vectors
Alternatively, generate independent variables and then combine them to create a new variable that they are correlated with. E.g....

alrededor de 1 mes ago | 0

For loop to evaluate Root Mean Square
I don't really understand what you mean by conditions, but maybe you can get what you want by thinking of a 2-step process where...

alrededor de 2 meses ago | 0

Compare empirical CDF and lognormal CDF
logncdf wants the mean and sd of the logged scores. Try this: fit_s=logncdf(sort(SD) , mean(log(SD)) , std(log(SD)) );

alrededor de 2 meses ago | 0

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How to plot a mixed density function?
x=-6:.01:10; pdf1 = normpdf(x,1,1); pdf2 = normpdf(x,4,1); mixpdf = 0.5*pdf1 + 0.5*pdf2; figure; plot(x,mixpdf);

alrededor de 2 meses ago | 0

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