All Questions
Tagged with mathematica r
9 questions
1
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1
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523
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Residuals not normal due to random effects structure
I am new to mixed-effect models and statistics, and I need to do a project for my thesis using mixed-effect modeling techniques.
My research aims to model how cardiovascular risk scores change over ...
- 11
0
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1
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2k
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How to read/visualise this confusion matrix?
I was offered a confusion matrix, which is called Parametrised 5x5 confusion matrix by authors where I extracted the values and where the diagonal has the correct results (0 in all); the results are ...
0
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2
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2k
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How to implement density-based clustering?
I’m looking to implement density-based clustering with R or Mathematica on a giant file (600,000 points on a 3 billion x 3 billion plane).
Is DBSCAN the right method for data that is this sparse? I am ...
- 31
1
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0
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53
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Measuring Autocorrelation in Tail Events
I have a single time series of financial data (stock index returns) and would like to study the autocorrelation among (log-)returns that are classified as "extreme", for example via exceedance of a ...
- 111
2
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1
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14k
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What is a good test for comparing frequency counts between two groups?
I am looking for statistical methods used to compare frequency of observations between two groups. I have two geographical locations with data on different soil types present.
for example, my data ...
- 21
1
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0
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915
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Problem with multivariate lognormal distribution in R [closed]
I'm using the R package compositions for the multivariate lognormal distribution. This is the only package I found that supports it.
However I'm not sure how this ...
- 1,781
0
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1
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99
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Difference in output from mvtnorm and Mathematica/Java [closed]
Let $a \sim\mathcal{N}(6.532056,0.06532056)$,$b \sim\mathcal{N}(8.390961,0.08390961)$ and $c \sim\mathcal{N}(8.736566,0.08736566)$. We use $\mathcal{N}(\mu,\sigma^2)$ notation unless specified ...
1
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2
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496
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Unkown 6-sided dice. After 600 rolls frequency for all sides exactly equal. What is the chance, that rolling "6" with this dice has frequency > 1/6?
Although it is unknown dice, the symmetry of the evidence tells us, that we can treat the dice as fair, so the chance should be exactly 50%.
But if we simulate it by hand, the result is less then 50%:...
- 2,200
2
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1
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4k
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Best multivariate polynomial regression
I have a dataset (x,y) where x is a n-dimensional vector and y is an m-dimensional vector. (m=3, n>2) My goal is to find the best polynomial in x fitting the (x,y) dataset.
The dimension of x is ...
- 267