[R] snowfall

[Santosh Srinivas]

Hello,

Just wondering why I am unable to run this in parallel.
A dput of my dataset is attached at the end. Please use to create my data
object.

I want to run this function in parallel (not sure if this is an efficient
implementation):

#Function to calculate the time to maturity for the option
require(fCalendar,quietly=TRUE) #Trying to calculate the trading days
require(fractalrock,quietly=TRUE) #Just to calculate the trading days
myFinCenter="Asia/Singapore"

getTimeToMaturity <- function(x){	
	tryCatch({
		toDt <- as.Date(as.character(x['EXPIRY_DT']), "%Y-%m-%d")
#Expiry Date
		fromDt <- as.Date(as.character(x['TIMESTAMP']), "%Y-%m-%d")
#Trade Timestamp
		NoOfDays <- NROW(getTradingDates(toDt,fromDt))
		return(NoOfDays/252)
	},
	error = function (ex){
		#print (paste("Error in",toDt,fromDt))
		NoOfDays <- 0
		return(NoOfDays/252)
	}
	)
}


Question: The following two lines work but the third and parallel one
doesn't ... why?

1) > apply(dNiftyOpt,1,getTimeToMaturity) #Works
         1          2          3          4          5          6          7
8          9         10         11         12         13         14
15         16         17         18         19         20 
0.02380952 0.01984127 0.07936508 0.02380952 0.01984127 0.01190476 0.02777778
0.02380952 0.01984127 0.01190476 0.02380952 0.01984127 0.02380952 0.02380952
0.01984127 0.02380952 0.01984127 0.02380952 0.02380952 0.02777778


library(snowfall)
2) > sfInit()
snowfall 1.84 initialized: sequential execution, one CPU.

> sfApply(dNiftyOpt,1,getTimeToMaturity) #Works
         1          2          3          4          5          6          7
8          9         10         11         12         13         14
15         16         17         18         19         20 
0.02380952 0.01984127 0.07936508 0.02380952 0.01984127 0.01190476 0.02777778
0.02380952 0.01984127 0.01190476 0.02380952 0.01984127 0.02380952 0.02380952
0.01984127 0.02380952 0.01984127 0.02380952 0.02380952 0.02777778 

> sfStop()


DOESN'T WORK: 3) 
> sfInit( parallel=TRUE, cpus=4 );
> sfApply(dNiftyOpt,1,getTimeToMaturity) #Added the time to maturity.
DOESN'T WORK?
 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 
 0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0 
> sfStop();



My dataset:
dput(dNiftyOpt)

structure(list(INSTRUMENT = c("OPTIDX", "OPTIDX", "OPTIDX", "OPTIDX", 
"OPTIDX", "OPTIDX", "OPTIDX", "OPTIDX", "OPTIDX", "OPTIDX", "OPTIDX", 
"OPTIDX", "OPTIDX", "OPTIDX", "OPTIDX", "OPTIDX", "OPTIDX", "OPTIDX", 
"OPTIDX", "OPTIDX"), SYMBOL = c("NIFTY", "NIFTY", "NIFTY", "NIFTY", 
"NIFTY", "NIFTY", "NIFTY", "NIFTY", "NIFTY", "NIFTY", "NIFTY", 
"NIFTY", "NIFTY", "NIFTY", "NIFTY", "NIFTY", "NIFTY", "NIFTY", 
"NIFTY", "NIFTY"), EXPIRY_DT = c("2004-01-29", "2004-01-29", 
"2004-01-29", "2004-01-29", "2004-01-29", "2004-01-29", "2004-01-29", 
"2004-01-29", "2004-01-29", "2004-01-29", "2004-01-29", "2004-01-29", 
"2004-01-29", "2004-01-29", "2004-01-29", "2004-01-29", "2004-01-29", 
"2004-01-29", "2004-01-29", "2004-01-29"), STRIKE_PR = c(1780, 
1780, 1800, 1800, 1800, 1800, 1800, 1800, 1800, 1800, 1820, 1820, 
1820, 1830, 1830, 1830, 1830, 1840, 1840, 1850), OPTION_TYP = c("PE", 
"PE", "CE", "CE", "CE", "CE", "PE", "PE", "PE", "PE", "CE", "CE", 
"PE", "CE", "CE", "PE", "PE", "CE", "PE", "CE"), SETTLE_PR = c(27.4, 
5.7, 152.95, 28.6, 70.45, 111.35, 14.75, 39.2, 8.6, 2.35, 20.4, 
54.2, 50.15, 18.35, 47.25, 51.75, 15.5, 14.95, 57.95, 26.3), 
    TIMESTAMP = c("2004-01-22", "2004-01-23", "2004-01-02", "2004-01-22", 
    "2004-01-23", "2004-01-27", "2004-01-21", "2004-01-22", "2004-01-23", 
    "2004-01-27", "2004-01-22", "2004-01-23", "2004-01-22", "2004-01-22", 
    "2004-01-23", "2004-01-22", "2004-01-23", "2004-01-22", "2004-01-22", 
    "2004-01-21"), Underlying = c(1770.5, 1847.55, 1946.05, 1770.5, 
    1847.55, 1904.7, 1824.6, 1770.5, 1847.55, 1904.7, 1770.5, 
    1847.55, 1770.5, 1770.5, 1847.55, 1770.5, 1847.55, 1770.5, 
    1770.5, 1824.6), UnderlyingVol = c(0.293906144944403, 0.331877179605752,

    0.129552369208600, 0.293906144944403, 0.331877179605752, 
    0.348918971622834, 0.276334860399362, 0.293906144944403, 
    0.331877179605752, 0.348918971622834, 0.293906144944403, 
    0.331877179605752, 0.293906144944403, 0.293906144944403, 
    0.331877179605752, 0.293906144944403, 0.331877179605752, 
    0.293906144944403, 0.293906144944403, 0.276334860399362)), .Names =
c("INSTRUMENT", 
"SYMBOL", "EXPIRY_DT", "STRIKE_PR", "OPTION_TYP", "SETTLE_PR", 
"TIMESTAMP", "Underlying", "UnderlyingVol"), row.names = c("1", 
"2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", 
"14", "15", "16", "17", "18", "19", "20"), class = "data.frame")