Continuing in the context of this previous post… 1. Select a static symbol from the R sources, like Connections $ grep "static Rconnection Connections" src/main/connections.c static Rconnection Connections; 2. Get its address $ objdump -t `R RHOME`/bin/exec/R | awk '/ Connections/ {print $1}' 000000000093b700 3. Use the symbol > library(inline) > code <- " +
Blog Archives
Plans for a Real tty Connection
I reverted the name of the tty connection that I described previously, to “serial” connection and updated the patch to R 2.11.1. This name is more appropriate to its function and also makes way for another patch I am working on which implements the full POSIX terminal interface (essentially all of termios.h). The connection provided
Access attribute_hidden Functions in R Packages
Maybe the title should have been prepended with “Don’t…” The source code of R is littered with “attribute_hidden” declarations. These declarations attempt to ensure that the variable or function may only be accessed by code in the core R distribution, and not by R extension packages. Generally there is a good reason for this. For
House Mountain Hike
My wife Mary and my Dad Wesley and I took a hike this weekend (5/14/10) to the House Mountain state recreation area in Knox county, Tennessee. The hike was about 3.8 miles with a total elevation gain of around 1000 feet (940.23ft by GPS). The plot below gives the elevation profile over the course of
Collect and Parse GPS (NMEA0183) Data in R
I recently wrote a serial connection for R-2.11.0 so that I can communicate with serial devices, for example an old Garmin eTrex Legend. This GPS device is able to output NMEA0183 sentences to a standard serial port (4800,8,1,N). I hooked up the device and used the serial connection to collect some data using some R
A serial Connection for R
***UPDATED: June 3, 2010 – revert name from “tty” to “serial“, R version (2.11.1)*** I’m working on a patch for R (currently 2.11.1) that adds a serial connection feature for POSIX systems (i.e. Linux, Mac OS X, …). The serial connection works like the other connections. For example, the following code opens, writes a single
Matrix determinant with the Lapack routine dspsv
The Lapack routine dspsv solves the linear system of equations Ax=b, where A is a symmetric matrix in packed storage format. However, there appear to be no Lapack functions that compute the determinant of such a matrix. We need to compute the determinant, for instance, in order to compute the multivariate normal density function. The
ECG Signal Processing
After reading (most of) “The Scientists and Engineers Guide to Digital Signal Processing” by Steven W. Smith, PhD, I decided to take a second crack at the ECG data. I wrote a set of R functions that implement a windowed (Blackman) sinc low-pass filter. The convolution of filter kernel with the input signal is conducted
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
