Functions Used in the Book "Computational Physics with R".
comphy is an R package accompanying the book This package accompanies the book
Computational Physics with R. It collects all the functions described and used throughout the book, providing ready-to-use implementations of numerical algorithms in computational physics.
The package includes routines for:
Numerical differentiation and integration
Solvers for ordinary differential equations
Sturm–Liouville eigenvalue problems
Monte Carlo methods
Other algorithms relevant to physics and applied mathematics
Installation
You can install the development version from GitHub with:
# install.packages("devtools")
devtools::install_github("jfoadi/comphy")
Example
This is a simple example where a numerical derivative of sin(x) is computed using comphy:
library(comphy)
# Grid of known values
x <- seq(0,pi,length.out=11)
# Grid of values at which derivative must be calculated
# Same as x
x0 <- x
# Function known at tabulated points
f <- sin(x)+cos(x)
# Obtain a numerical derivative at those points
# using central differences (discard first and last value)
df <- deriv_reg(x0,x,f)
# Print derivative values
print(df)
#> [1] NA 0.6315304 0.2176105 -0.2176105 -0.6315304 -0.9836316
#> [7] -1.2394482 -1.3739389 -1.3739389 -1.2394482 NA
The two NA’s are there because the derivative is calculated using a centred difference.
Documentation
All exported functions include documentation and usage examples. For a comprehensive discussion and context, see the book Computational Physics with R.
License
GPL (>= 2)