Publications by Radford Neal
New release of pqR, with a curated repository
I have released a new version, pqR-2014-06-19, of my speedier, “pretty quick”, implementation of R. This and the previous release (pqR-2014-02-23) are maintenance releases, with bug fixes, improved documentation, and better test procedures. The result is that pqR now works with a large collection of 3438 packages. This collection was crea...
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New version of pqR with faster variable lookup, faster subset replacement, and more
I’ve released a new version, pqR-2014-09-30, of my speedier, “pretty quick”, implementation of R, with some major performance improvements, and some features from recent R Core versions. It also has fixes for bugs (some also in R-3.1.1) and installation glitches. Details are in pqR NEWS. Here I’ll highlight some of the more interest...
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Subset replacement in pqR: Now faster and better
The latest version of pqR that I just released uses a new way of implementing subset replacement operations — such as a[i] or L$M[1:100,i]. The new approach is much faster, and eliminates some strange behaviour of the previous approach. This change affects only interpreted code. The bytecode compiler (available since R-2.13.0) introduced a d...
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How large vectors in R might be stored compactly
Vectors in R can currently have elements of two sizes — 8-byte double-precision floating-point elements for `numeric’ vectors, or 4-byte elements for `integer’ or `logical’ vectors. You can also have vectors whose elements are 1-byte `raw’ values, but these raw vectors don’t support negative numbers, or NA values, so they aren�...
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Exact computation of sums and means
A while ago, I came across a mention of the Python math.fsum function, which sums a set of floating-point values exactly, then rounds to the closest floating point value. This seemed useful. In particular, I thought that if it’s fast enough it could be used instead of R’s rather primitive two-pass approach to trying to compute the sample mea...
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What can global temperature data tell us?
Debates about anthropogenic climate change often centre around data on changes in global temperatures over the last few decades. There are good scientific reasons to look at this data, but it also plays a prominent role in political advocacy, sometimes fairly, sometimes not so fairly. This is the first in a series of posts in which I’ll discuss...
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Has there been a ‘pause’ in global warming?
As I discussed in my previous post, records of global temperatures over the last few decades figure prominently in the debate over the climate effects of CO2 emitted by burning fossil fuels. I am interested in what this data says about which of the reasonable positions in this debate is more likely to be true — the `warmer’ position, that...
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Critique of ‘Debunking the climate hiatus’, by Rajaratnam, Romano, Tsiang, and Diffenbaugh
Records of global temperatures over the last few decades figure prominently in the debate over the climate effects of CO2 emitted by burning fossil fuels, as I discussed in my first post in this series, on What can global temperature data tell us? One recent controversy has been whether or not there has been a `pause’ (also referred to as a `...
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Fixing R’s design flaws in a new version of pqR
I’ve released a new version of my pqR implementation of R. This version introduces extensions to the R language that fix some long-standing design flaws that were inherited from S. These language extensions make it easier to write reliable programs, that work even in edge cases, such as data sets with one observation. In particular, the e...
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New release of pqR — faster, and now compatible with R-2.15.1
I have released a new version of my “pretty quick” R interpreter, pqR-2016-10-05. One major change with this version is that pqR, which was based on R-2.15.0, is now compatible with R-2.15.1. This allows for an increased number of packages in the pqR repository. This release also has some significant speed improvements, a new form of ...
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