# Monthly Archives: January 2013

## Monotonic deshrinking in weighted averaging models

January 5, 2013
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$Monotonic deshrinking in weighted averaging models$

Weighted averaging regression and calibration is the most widely used method for developing a palaeolimnological transfer function. Such models are used to reconstruct properties of the past lake environment such as pH, total phosphorus, and water temperature with, it has … Continue reading →

## Infinite generators in R

January 5, 2013
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This is first in a series of posts about creating simulations in R. As a foundational discussion, I first look …Continue reading »

## What’s that “pre- and post-multiply” stuff?

January 5, 2013
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Often in SEM scripts you will see matrices being pre- and post-multiplied by some other matrix. For instance, this figures in scripts computing the genetic correlation between variables. How does pre- and post-multiplying a variance...

## National identification number: Finland part 3

January 5, 2013
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Last part of our short series about the Finnish social security number (Fssn). You can check part 1 here, and part 2 here. This last post we are interested in generating random Fssn's. This has no real world applications. It is just a coding excercis...

## National identification number: Finland part2

January 5, 2013
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Continuing our theme from last time. The Finnish social security number (FSSn) has the form xxxxxxyzzzq, where the check digit is q. If you want to check if the FSSn is real the check digit is matched to the remainder of xxxxxxzzz / 31. The check di...

## Calling R Functions from C++

January 5, 2013
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At its very essence, Rcpp permits easy access to native R objects at the C++ level. R objects can be simple vectors, list or matrices; compound data structures created from these; objects of S3, S4 or Reference Class vintage; or language objects a...

## Find Out Available Usernames with R

January 5, 2013
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Update on 2013/01/05: Xiao Nan in the comments pointed out that apply(combn(letters, 2), 2, paste0, collapse = '') was wrong for all two-letter usernames, and indeed it was. It is not a combination problem. Now I use his elegant outer() solution. One can also use expand.grid(letters, letters). Github decided to take off their downloads service, and I was very...

## Monotonic deshrinking in weighted averaging models

January 5, 2013
By

Weighted averaging regression and calibration is the most widely used method for developing a palaeolimnological transfer function. Such models are used to reconstruct properties of the past lake environment such as pH, total phosphorus, and water temperature with, it has to be said, varying degrees of success and usefulness. In simple weighted averaging (WA) there is little to specify other...

## IBS reversion edge with QuantShare

January 4, 2013
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Happy New Years to readers; my resolution this year is to continue delivering thoughts and ideas to others in the hopes that we all might be able to benefit somewhat from sharing observations. I'll start by describing an edge using QuantShare as the b...