Splitter {TrackReconstruction}

Splits large data files by date and time.

Description

This function takes the large data files inherently produced by accelerometer and magnetometer biologgers and splits them into smaller files so that the TrackReconstruction functions can handle them or it splits the data between trips or GPS locations or however is needed. The splitting is done via matching Time and Date as character strings.

Usage

Splitter(TagFile,Begin,End,RmL,Hz)

Arguments

TagFile

Matrix or data frame of magnetometer and accelerometer and other data collected by biologgers with column headings specified in Details.

Begin

A vector of DateTime such as 2009-08-12 05:45:35.0625 indicating the time that the new files should begin. Format must be the same as the Date and Time data in the TagFile, though the TagFile Date and Time need not be in the same column.

End

A vector of DateTime such as 2009-08-12 05:45:35.0625 indicating the time that the new files should end. Format must be the same as the Date and Time data in the TagFile, though the TagFile Date and Time need not be in the same column.

RmL

Running mean length in seconds, required to calculate the amount of time beyond the Begin and End times that is required for the DeadReckoning function and is trimmed off by the DeadReckoning function.

Hz

Frequency of Accelerometer data collection in Hz, required to calculate the amount of time beyond the Begin and End times that is required for the DeadReckoning function and is trimmed off by the DeadReckoning function.

Details

TagFile must have columns named DateTime or separated as Date and Time. Begin and End must be in the same format as the DateTime column in TagFile or have the same format as the Date and Time columns when they are pasted together by Splitter. For example, if DateTime is 2009-08-21 14:08:06.0625, then Begin and End cannot be Jul/21/2009 14:08:06.0625. See strptime for formatting date and time data. If TagFile has a Date column of 2009-08-21 and a Time column of 14:08:06.0625, Splitter will paste them together for you to look like 2009-08-21 14:08:06.0625. You must have enough time on the beginning and end of the TagFile equivalent to RmL*Hz/2 before the first DateTime in the Begin vector and after the last DateTime in the End vector. If your Hz is greater than 1 and you do not have data on fractions of a second, then each time stamp will have copies equal to your sampling Hz. In such a case, the program matches with the first instance of the DateTime and warnings will be given, this may be important when calculating RmL*Hz/2 tails.

Value

Creates a list of data frames in the format of the TagFile, but with a single DateTime column if the TagFiles had separate Date and Time columns.

Author(s)

Brian Battaile

Examples

#data set with 6 associated GPS fixes in the "gpsdata" data set
data(rawdata)
data(gpsdata02)
Begin=gpsdata02$DateTime[2:6]
End=gpsdata02$DateTime[3:7]
splits<-Splitter(rawdata,Begin,End,RmL=2,Hz=16)
## Not run: 
#The following is code to write your many new files
setwd() #first fill in the path to the folder where you want the data to be written to
for(i in 1:length(splits))
{
	num<-i
	num=ifelse(num<10 & length(Begin)>10,paste("0",num,sep=""),num)
		num=ifelse(num<100 & length(Begin)>100,paste("0",num,sep=""),num)
		num=ifelse(num<1000 & length(Begin)>1000,paste("0",num,sep=""),num)
		num=ifelse(num<10000 & length(Begin)>10000,paste("0",num,sep=""),num)
	#Create a name for the file
	Nombre<-paste("Animal01Trip03GPS_Section",num,".txt",sep="")
	write.table(splits[[i]],Nombre,sep="\t",row.names=FALSE,quote=FALSE)
	}

## End(Not run)