badele · December 8, 2021 08:02 · Dec 8, 2021 · Nov 23, 2021 · Nov 20, 2021 · Nov 20, 2021
diff --git a/read_and_write_fwf.R b/read_and_write_fwf.R
@@ -26,13 +26,15 @@ write_fwf <- function(df, filename,rowname = FALSE,nbspaces = 3, replace_na = "N
     df <- tibble::rownames_to_column(df, rowname)
   }
 
-  # Replace NA
-  df[is.na(df)] <- replace_na
+  # Convert all columns to character
+  tmpdf = data.frame(df)
+  tmpdf[] <- lapply(df, as.character)
 
   # Compute column size
-  maxwidthname <- nchar(colnames(df))
-  maxwidthvalue <- sapply(df, function(x) max(nchar(x)))
-  maxcols <- pmax(maxwidthname,maxwidthvalue)
+  nasize=nchar(replace_na)
+  maxwidthname <- nchar(colnames(tmpdf))
+  maxwidthvalue <- sapply(tmpdf, function(x) max(nchar(x)))
+  maxcols <- pmax(maxwidthname,maxwidthvalue,nasize)
   delta <- maxwidthvalue - maxwidthname 
 
   # Compute header
@@ -56,7 +58,16 @@ write_fwf <- function(df, filename,rowname = FALSE,nbspaces = 3, replace_na = "N
   close(file)
 
   # Export data
-  write.fwf(df,file=filename,append=TRUE, width=maxcols,colnames=FALSE,na=replace_na, sep=strrep(" ",nbspaces))
+  write.fwf(
+    df,
+    file=filename,
+    append=TRUE, 
+    width=maxcols,
+    colnames=FALSE,
+    na=replace_na, 
+    sep=strrep(" ",nbspaces),
+    justify="left"
+  )
 }
 
 #' Read automatically .fwf file (fixed width file) in R
@@ -79,5 +90,5 @@ read_fwf <- function(filename,maxsearchlines=100) {
   colwidths <- str_split(colwidths, ",")
   colwidths <- strtoi(unlist(colwidths))
 
-  return(read.fwf(file=filename, skip=idxcols+2, col.names = colnames, widths=colwidths,strip.white=TRUE))
+  return(read.fwf(file=filename, skip=idxcols+1, col.names = colnames, widths=colwidths,strip.white=TRUE))
 }
diff --git a/read_and_write_fwf.R b/read_and_write_fwf.R
@@ -21,11 +21,15 @@ suppressPackageStartupMessages({
 #' Datsun 710            22.8     4   108.0    93   3.85   2.320   18.61    1    1      4      1
 #' Hornet 4 Drive        21.4     6   258.0   110   3.08   3.215   19.44    1    0      3      1
 write_fwf <- function(df, filename,rowname = FALSE,nbspaces = 3, replace_na = "NA") {
-  # Compute columns size
+  # Convert rownames to column
   if (rowname) {
     df <- tibble::rownames_to_column(df, rowname)
   }
-
+
+  # Replace NA
+  df[is.na(df)] <- replace_na
+
+  # Compute column size
   maxwidthname <- nchar(colnames(df))
   maxwidthvalue <- sapply(df, function(x) max(nchar(x)))
   maxcols <- pmax(maxwidthname,maxwidthvalue)

diff --git a/read_and_write_fwf.R b/read_and_write_fwf.R
@@ -6,6 +6,10 @@ suppressPackageStartupMessages({
 #' Generate automatically .fwf file (fixed width file) in R
 #' @description This function creates automatically fixed width file
 #' It align columns headers with datas
+#' @param df dataframe   
+#' @param filename filename   
+#' @param nbspaces nb spaces for columns separator   
+#' @param replace_na Empty/NA chain replacement   
 #' @param rowname If it's defined, it convert rownames column to named column   
 #' @examples write_fwf(mtcars, "carname", "/tmp/mtcars.fwf")
 #'

diff --git a/read_and_write_fwf.R b/read_and_write_fwf.R
@@ -0,0 +1,75 @@
+suppressPackageStartupMessages({
+    library(gdata)
+    library(stringr)
+})
+
+#' Generate automatically .fwf file (fixed width file) in R
+#' @description This function creates automatically fixed width file
+#' It align columns headers with datas
+#' @param rowname If it's defined, it convert rownames column to named column   
+#' @examples write_fwf(mtcars, "carname", "/tmp/mtcars.fwf")
+#'
+#' # colnames: carname,mpg,cyl,disp,hp,drat,wt,qsec,vs,am,gear,carb
+#' # cols: 22,7,6,8,6,7,8,8,5,5,7,7
+#' carname                mpg   cyl    disp    hp   drat      wt    qsec   vs   am   gear   carb
+#' Mazda RX4             21.0     6   160.0   110   3.90   2.620   16.46    0    1      4      4
+#' Mazda RX4 Wag         21.0     6   160.0   110   3.90   2.875   17.02    0    1      4      4
+#' Datsun 710            22.8     4   108.0    93   3.85   2.320   18.61    1    1      4      1
+#' Hornet 4 Drive        21.4     6   258.0   110   3.08   3.215   19.44    1    0      3      1
+write_fwf <- function(df, filename,rowname = FALSE,nbspaces = 3, replace_na = "NA") {
+  # Compute columns size
+  if (rowname) {
+    df <- tibble::rownames_to_column(df, rowname)
+  }
+
+  maxwidthname <- nchar(colnames(df))
+  maxwidthvalue <- sapply(df, function(x) max(nchar(x)))
+  maxcols <- pmax(maxwidthname,maxwidthvalue)
+  delta <- maxwidthvalue - maxwidthname 
+
+  # Compute header
+  header <- c()
+  for (idx in seq(ncol(df))) {
+    if (is.character(df[,idx])) {
+      header <- append(header,paste0(colnames(df)[idx],strrep(" ",max(delta[idx],0))))
+    } else {
+      header <- append(header,paste0(strrep(" ",max(delta[idx],0)), colnames(df)[idx]))
+    }
+  }
+
+  # Open file
+  file <- file(filename, "w")
+
+  # Write header
+  writeLines(paste("# colnames:", paste(colnames(df), collapse=',')),file)
+  writeLines(paste("# cols:", paste(unlist(maxcols+nbspaces), collapse=',')),file)
+  writeLines(header,file, sep=strrep(" ",nbspaces))
+  writeLines("", file, sep="\n")
+  close(file)
+
+  # Export data
+  write.fwf(df,file=filename,append=TRUE, width=maxcols,colnames=FALSE,na=replace_na, sep=strrep(" ",nbspaces))
+}
+
+#' Read automatically .fwf file (fixed width file) in R
+#' @description This function read and detect automatically fixed width file
+#' @param maxsearchlines nb lines for the searching the columns metadata description   
+#' @examples read_fwf("/tmp/mtcars.fwf")
+read_fwf <- function(filename,maxsearchlines=100) {
+  # Search columns informations
+  file <- file(filename, "r")
+  on.exit(close(file))
+
+  lines <- readLines(file,n=maxsearchlines)
+
+  idxname <- str_which(lines,"# colnames: ")
+  colnames <- str_replace(lines[idxname], "# colnames: ", "")
+  colnames <- unlist(str_split(colnames, ","))
+
+  idxcols <- str_which(lines,"# cols: ")
+  colwidths <- str_replace(lines[idxcols], "# cols: ", "")
+  colwidths <- str_split(colwidths, ",")
+  colwidths <- strtoi(unlist(colwidths))
+
+  return(read.fwf(file=filename, skip=idxcols+2, col.names = colnames, widths=colwidths,strip.white=TRUE))
+}