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13375
bio website linkedin.com/pub/andy-ross/14/…
location Columbia, MO
age 32
visits member for 3 years, 2 months
seen 3 hours ago

Dec
8
comment Copula - Correlation or Covariance
Allowing for the Covariance is more general than using a Correlation matrix. You can assume unit variance and they are equivalent.
Dec
7
comment Most efficient searching algorithm in a table
@Rojo that is a very clean and fast solution (though not quite as fast as the compiled function). I didn't even know about FirstPosition so thanks for that! It is worth noting that for machine reals this looks for exact equal, even adding $MachineEpsilon will cause it to return Missing["NotFound"].
Dec
6
revised Most efficient searching algorithm in a table
added 415 characters in body
Dec
6
revised Most efficient searching algorithm in a table
deleted 45 characters in body
Dec
6
revised Most efficient searching algorithm in a table
added 379 characters in body
Dec
6
revised Most efficient searching algorithm in a table
added 379 characters in body
Dec
6
answered Most efficient searching algorithm in a table
Dec
6
comment The CorrelationMatrix is equal to corrcoef of Matlab?
It's not a dumb question but it is difficult to verify without both software packages and the right expertise. I do know that the Mathematica property is the correlation of the parameters ( the diagonal of the covariance matrix property is their variances) a brief look at the docs for the matlab function makes me think it is more akin to mathematicas Correlation function rather than the fitted model property.
Dec
6
comment Time Series fit in Mathematica
The built in functions for time series dont currently handle covariates. I highly recommend looking at RLink since R has some fantastic and very mature time series functionality like the auto.arima function.
Dec
5
comment Method of moments using just the moments?
@bills however if the moments they have are the parameters they wouldn't need to estimate. I think they have a situation where the parameters of interest are some function of the moments
Dec
5
comment Method of moments using just the moments?
You will have to do this yourself but depending on the distribution it shouldn't be difficult. If you need help with a particular example you can always add it to your question.
Dec
4
answered A simple expression that Mathematica can't simplify
Dec
1
comment FindDistributionParameters and Hypothesis Testing
Not off hand. I'm sure someone over at stats.stackexchange.com could get you started
Dec
1
revised FindDistributionParameters and Hypothesis Testing
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Dec
1
answered FindDistributionParameters and Hypothesis Testing
Dec
1
comment Drawing a square root spiral
That is a beautiful result! +1
Nov
28
comment Generating Random Real numbers with certain numbers not included
I might ask how sure you need to be. The probability of generating a machine number that is detected as equal to 3. is very very small. Somewhere on the order of 10^-12 when you only generate 1000 of them in that range. It is about two orders of magnitude smaller if you are checking for equivalence (===).
Nov
24
comment Compilation of a function that needs to call Subsets
You are much more likely to get a response with some short example code that demonstrates what you are trying to do.
Nov
19
comment Strange interaction between Module and ListPlot
I can reproduce this on "10.0 for Mac OS X x86 (64-bit) (September 10, 2014)" using OS X Yosemite. Must be a platform-specific bug. You should report it to WRI.
Nov
19
comment Strange interaction between Module and ListPlot
What version are you using? I've tried this on Windows M9 and M10 and don't see the issue.