Merging Two Headings Into One - r

Question

Very simple question. I am using an excel sheet that has two rows for the column headings; how can I convert these two row headings into one? Further, these headings don't start at the top of the sheet.
Thus, I have DF1
Temp Press Reagent Yield A Conversion etc
degC bar /g % %
1 2 3 4 5
6 7 8 9 10
and I want,
Temp degC Press bar Reagent /g Yield A % Conversion etc
1 2 3 4 5
6 7 8 9 10
Using colnames(DF1) returns the upper names, but getting the second line to merge with the upper one keeps eluding me.

Answer 1

Using your data, modified to quote text fields that contain the separator (get whatever tool you used to generate the file to quote text fields for you!)
txt <- "Temp Press Reagent 'Yield A' 'Conversion etc'
degC bar /g % %
1 2 3 4 5
6 7 8 9 10
"
this snippet of code below reads the file in two steps
First we read the data, so skip = 2 means skip the first 2 lines
Next we read the data again but only the first two line, this output is then further processed by sapply() where we paste(x, collapse = " ") the strings in the columns of the labs data frame. These are assigned to the names of dat
Here is the code:
dat <- read.table(text = txt, skip = 2)
labs <- read.table(text = txt, nrows = 2, stringsAsFactors = FALSE)
names(dat) <- sapply(labs, paste, collapse = " ")
dat
names(dat)
The code, when runs produces:
> dat <- read.table(text = txt, skip = 2)
> labs <- read.table(text = txt, nrows = 2, stringsAsFactors = FALSE)
> names(dat) <- sapply(labs, paste, collapse = " ")
>
> dat
Temp degC Press bar Reagent /g Yield A % Conversion etc %
1 1 2 3 4 5
2 6 7 8 9 10
> names(dat)
[1] "Temp degC" "Press bar" "Reagent /g"
[4] "Yield A %" "Conversion etc %"
In your case, you'll want to modify the read.table() calls to point at the file on your file system, so use file = "foo.txt" in place of text = txt in the code chunk, where "foo.txt" is the name of your file.
Also, if these headings don't start at the top of the file, then increase skip to 2+n where n is the number of lines before the two header rows. You'll also need to add skip = n to the second read.table() call which generates labs, where n is again the number of lines before the header lines.

Answer 2

This should work. You only need set stringsAsFactors=FALSE when reading data.
data <- structure(list(Temp = c("degC", "1", "6"), Press = c("bar", "2",
"7"), Reagent = c("/g", "3", "8"), Yield.A = c("%", "4", "9"),
Conversion = c("%", "5", "10")), .Names = c("Temp", "Press",
"Reagent", "Yield.A", "Conversion"), class = "data.frame", row.names = c(NA,
-3L)) # Your data
colnames(data) <-paste(colnames(dados),dados[1,]) # Set new names
data <- data[-1,] # Remove first line
data <- data.frame(apply(data,2,as.real)) # Correct the classes (works only if all collums are numbers)

Answer 3

Just load your file with read.table(file, header = FALSE, stringsAsFactors = F) arguments. Then, you can grep to find the position this happens.
df <- data.frame(V1=c(sample(10), "Temp", "degC"),
V2=c(sample(10), "Press", "bar"),
V3 = c(sample(10), "Reagent", "/g"),
V4 = c(sample(10), "Yield_A", "%"),
V5 = c(sample(10), "Conversion", "%"),
stringsAsFactors=F)
idx <- unique(c(grep("Temp", df$V1), grep("degC", df$V1)))
df2 <- df[-(idx), ]
names(df2) <- sapply(df[idx, ], function(x) paste(x, collapse=" "))
Here, if you want, you can then convert all the columns to numeric as follows:
df2 <- as.data.frame(sapply(df2, as.numeric))