#' Extracts the drift check information from asc files (for data quality
#' monitoring, etc.)
#'
#' @author Martin R. Vasilev
#'
#' @param data_list Input of data files to be processed. This can be specified in three ways:
#' 1) a directory that contains all the files (it will select all files ending with ".asc",
#' and order them by participant number, if present).
#' 2) Directory to a txt file that contains all the .asc data file names inside:
#' e.g., data_list= "C:/My Data/data_list.txt".
#' In the .txt file, the directory for each .asc data file should appear on a separate row,
#' e.g.: C:/My Data/subject1.asc /n
#' C:/My Data/subject2.asc
#' 3) A directory to a single .asc file: e.g., data_list= "C:/My Data/subject1.asc".
#'
#' @return A data frame containing the drift check data
#'
#' @example
#' drift_data<- Drift(data_list= "D:/Data/subject1.asc")
#'
#' @include utility.R
Drift<- function(data_list){
# check if user provided data dir:
if(length(data_list)==0){
data_list= file.choose() # make them chose a file
message("To process multiple files, please specify a directory in 'data_list'")
}
# check file input:
if(grepl('.txt', data_list)){
data<- readLines(data_list, warn=F) # process multiple files
}else{
if(grepl('.asc', data_list)){ # if a single .asc file was provided...
data<- data_list # process only 1 file
} else{ # otherwise, it must be a dir of files
data<- get_files(data_list)
}
}
message("Note that since Eyelink 1000 only drift check is performed,
meaning that no correction to the calibration is made.\n")
df<- NULL
for (i in 1:length(data)){ # for each subject:
filename= data[i]
file<- readLines(data[i]) # load file
line<- which(grepl('DRIFTCORRECT', file))
text<- file[line]
# remove aborted drift checks
whichAbort<- grep("ABORTED", text)
nAborted<- length(text[whichAbort])
if(nAborted>0){
text<- text[-whichAbort]
}
# Remove repeated drift checks:
whichRepeat<- grep("REPEATING", text)
nRepeated<- length(text[whichRepeat])
if(nRepeated>0){
text<- text[-whichRepeat]
}
# Remove failed drift checks:
whichFail<- grep("DRIFTCORRECT_FAILED", text)
nFailed<- length(text[whichFail])
if(nFailed>0){
text<- text[-whichFail]
}
# parse message text:
out <- do.call( rbind, strsplit( text, '\t' ) )
out<- out[, 2]
out <- do.call( rbind, strsplit(out, ' ' ) )
# remove empty columns that can mess up parsing sometimes:
out<- out[, colSums(out != "") != 0]
time_stamp<- as.numeric(out[,1])
eye<- out[, 4]
offset<- as.numeric(out[,8])
pos<- as.numeric(unlist(strsplit(out[,6], ',')))
x_pos<- pos[c(TRUE, FALSE)]
y_pos<- pos[c(FALSE, TRUE)]
pix_offset<- as.numeric(unlist(strsplit(out[,10], ',')))
x_offset<- pix_offset[c(TRUE, FALSE)]
y_offset<- pix_offset[c(FALSE, TRUE)]
sub= rep(i, length(time_stamp))
df_temp<- try(data.frame(sub, time_stamp, eye, offset, x_pos, y_pos, x_offset, y_offset))
try(assign('df_temp$filename', filename))
CatchLargeError<- which(abs(df_temp$offset)>5000)
if(length(CatchLargeError)>0){
ErrorExcluded<- df_temp$offset[CatchLargeError]
warning(sprintf("Excessively large offset error detected for subject %g: %f!!! Excluded from analysis!\n\n", i, round(ErrorExcluded,1)))
# remove from data frame to prevent messing up stats:
df_temp<- df_temp[-CatchLargeError,]
}
df<- try(rbind(df, df_temp))
try(cat(sprintf("Subject %i offset: mean: %.3f, SD: %.3f, range: %.3f - %.3f (%i aborted, %i repeated)",
i, mean(df_temp$offset), sd(df_temp$offset), range(df_temp$offset)[1],
range(df_temp$offset)[2], nAborted, nRepeated)))
cat("\n")
}
return(df)
}
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.