@ -3,6 +3,7 @@
# Taha Ahmed, Jan 2011
# CONTENTS
# >>>> ConvertRefPot
# >>>> Celsius2Kelvin
# >>>> Kelvin2Celsius
# >>>> as.radians
@ -11,6 +12,55 @@
##################################################
################# ConvertRefPot ##################
##################################################
ConvertRefPot <- function ( argpotential , argrefscale , valuerefscale ) {
# Converts from some reference potential scale into another
# SHE: standard hydrogen electrode scale
# Ag/AgCl: silver silver-chloride electrode scale
# SCE: standard calomel scale
#
##### Add more reference electrodes here >>
refpotatSHEzero <- c ( 0 , -0.21 , -0.24 , 3 )
refrownames <- c ( " SHE" , " Ag/AgCl" , " SCE" , " Li/Li+" )
refcolnames <- c ( " SHE0" , " AgCl0" , " SCE0" , " Li0" )
##### Add more reference electrodes here <<
#
SHE0 <- data.frame ( matrix ( refpotatSHEzero , ncol = length ( refpotatSHEzero ) , byrow = T ) )
refpotmtx <- matrix ( NA , length ( SHE0 ) , length ( SHE0 ) )
refpotmtx [ , 1 ] <- matrix ( as.matrix ( SHE0 ) , ncol = 1 , byrow = T )
for ( c in 2 : length ( SHE0 ) ) {
# loop over columns (except the first)
for ( r in 1 : length ( SHE0 ) ) {
# loop over rows
refpotmtx [r , c ] <- refpotmtx [r , 1 ] - refpotmtx [c , 1 ]
}
}
refpotdf <- as.data.frame ( refpotmtx )
names ( refpotdf ) <- refcolnames
row.names ( refpotdf ) <- refrownames
## So far we have made a matrix of all the possible combinations,
## given the vector refpotatSHEzero. The matrix is not strictly necessary,
## but it may prove useful later. It does.
#
# Match argrefscale to the refrownames
argmatch <- match ( argrefscale , refrownames , nomatch = 0 )
# Match valuerefscale to the refrownames
valuematch <- match ( valuerefscale , refrownames , nomatch = 0 )
# We simply assume that the match was well-behaved
valuepotential <- argpotential + refpotdf [valuematch , argmatch ]
# Check that arg and value electrodes are within bounds for a match
if ( argmatch == 0 || valuematch == 0 ) {
# No match
# Perform suitable action
message ( " Arg out of bounds in call to ConvertRefPot" )
valuepotential <- NA
}
return ( valuepotential )
}
##################################################
############### Celsius2Kelvin ###################