R: Use faster vecLib

These code snippets have been tested on R 3.1.0 and Mac OS 10.9.3. They presumably do *not* work on R 2.X!

## Enter these commands in the Mac OS Terminal

# use faster vecLib library
cd /Library/Frameworks/R.framework/Resources/lib
ln -sf  /System/Library/Frameworks/Accelerate.framework/Frameworks/vecLib.framework/Versions/Current/libBLAS.dylib libRblas.dylib

# return to default settings
cd /Library/Frameworks/R.framework/Resources/lib
ln -sf libRblas.0.dylib libRblas.dylib

# R script for benchmarking:
# http://r.research.att.com/benchmarks/R-benchmark-25.R
# On 2011 Macbook Pro (2.7 GHz Core i7): 43 sec. (Rblas) vs. 9 sec. (vecLib)

system.time({ x <- replicate(5e3, rnorm(5e3)); tcrossprod(x) })

https://mpopov.com/blog/2021/10/10/even-faster-matrix-math-in-r-on-macos-with-m1/