Adding Headers to Dataframe in R - r

I have a script written in R that is ran weekly and produces a csv. I need to add headers over top of some of the column names as they are grouped together.
Header1 Header2
A B C D E F
1 2 3 4 5 6
7 8 9 a b c
In this example ABC columns are under the "Header1" header, and DEF are under the "Header2" header. Obviously this can be done manually but I was curious if there was a package that can do this. "No" is an acceptable answer.
EDIT: should of added that the file can also be a xlsx. Initially I write off most of my files as CSVs since they usually get used by a script again at some point.

It is a bit ugly but you can do on a csv as long as you do not require any merging of cells. I used data.table in my example, but I am pretty sure you can use any other writing function as long as you write the headers with append = FALSE and col.names = FALSE and the data both with TRUE. Reading it back gets a bit ugly but you can skip the first row.
dt <- fread("A B C D E F
1 2 3 4 5 6
7 8 9 a b c")
fwrite(data.table(t(c("Header1", NA, NA, "Header2", NA, NA))), "test.csv", append = FALSE, col.names = FALSE)
fwrite(dt, "test.csv", append = TRUE, col.names = TRUE)
fread("test.csv")
# V1 V2 V3 V4 V5 V6
# 1: Header1 Header2
# 2: A B C D E F
# 3: 1 2 3 4 5 6
# 4: 7 8 9 a b c
fread("test.csv", skip = 1L)
# A B C D E F
# 1: 1 2 3 4 5 6
# 2: 7 8 9 a b c
If you happen to want your header information back you can do something like this. Read the first line, find the positions of the headers and find the headers itself.
headers <- strsplit(readLines("test.csv", n = 1L), ",")[[1]]
which(headers != "")
# [1] 1 4
headers[which(headers != "")]
# [1] "Header1" "Header2"

Related

Import multiple text file with first row's specific words

I will use two files as example to explain my question.
I have multiple text files like below:
### First file
GEORGIA file name first row not use
Col1 Col2
A 2
A 4
A 5
B 2
B 6
### Second file
New York file name first row not use
Col1 Col2
C 2
C 4
D 5
E 2
F 6
I use data.table to import text file and then extract information I want.
library(data.table)
my_read_data <- function(x){ data <- data.table::fread(x, header = T, strip.white = T, fill = T, skip = 1) }
file.list <- dir(path = "C:/Users/filesnames/", pattern='\\.txt', full.names = T)
dt.list <- sapply(file.list, my_read_data, simplify=FALSE)
cd <- rbindlist(dt.list, idcol = 'id')[, FileNo := substr(id, 24, 25)]
And the result is in the following:
Col1 Col2 FileNo
A 2 1
A 4 1
A 5 1
B 2 1
B 6 1
C 2 2
C 4 2
D 5 2
E 2 2
F 6 2
However, what I actually want is:
Col1 Col2 FileNo Name
A 2 1 GEORGIA
A 4 1 GEORGIA
A 5 1 GEORGIA
B 2 1 GEORGIA
B 6 1 GEORGIA
C 2 2 New York
C 4 2 New York
D 5 2 New York
E 2 2 New York
F 6 2 New York
Since I skip the first row, so I cannot extract the words from first row where I found from here.
But if I did not remove the first row, it imported incorrectly.
Text File shows like:
### First file
GEORGIA file name first row not use
Col1,Col2
A,2
A,4
A,5
B,2
B,6
### Second file
New York file name first row not use
Col1,Col2
C,2
C,4
D,5
E,2
F,6
We can read the first line separately and create a column
library(data.table)
rbindlist(lapply(setNames(file.list, file.list), function(x) {
dat <- fread(x, header = TRUE, strip.white = TRUE, fill = TRUE, skip = 1)
v1 <- readLines(x, n = 1)
dat[, Name := sub("\\s+file name.*", "", v1)]
}), idcol = 'id')

How to read when delimiter is space and missing values are blank?

I have a space delimited file and some columns are blank, so we end up having multiple spaces, and fread fails with error. But read.table works fine. See example:
library(data.table)
# R version 3.4.2 (2017-09-28)
# data.table_1.10.4-3
fread("A B C D
1 2 3
4 5 6 7", sep = " ", header = TRUE)
Error in fread("A B C D\n1 2 3\n4 5 6 7") :
Expected sep (' ') but new line, EOF (or other non printing character) ends field 2 when detecting types from point 0: 1 2 3
read.table(text ="A B C D
1 2 3
4 5 6 7", sep = " ", header = TRUE)
# A B C D
# 1 1 2 NA 3
# 2 4 5 6 7
How do we read using fread, I tried setting sep = " " and na.string = "", didn't help.
In fread function, by default strip.white is set to TRUE, meaning leading trailing spaces are removed. That is useful to read files with fixed width or with irregular number of spaces as separator.
Whereas in read.table strip.white by default is set to FALSE.
fread("A B C D
1 2 3
4 5 6 7", sep = " ", header = TRUE, strip.white = FALSE)
# A B C D
# 1: 1 2 NA 3
# 2: 4 5 6 7
Note: Providing self-answer as I couldn't find relevant post, also this tripped me over once and twice.
Edit: This doesn't work anymore for data.table_1.12.2, related GitHub Issue.

Speed up data.frame rearrangement

I have a data frame with coordinates ("start","end") and labels ("group"):
a <- data.frame(start=1:4, end=3:6, group=c("A","B","C","D"))
a
start end group
1 1 3 A
2 2 4 B
3 3 5 C
4 4 6 D
I want to create a new data frame in which labels are assigned to every element of the sequence on the range of coordinates:
V1 V2
1 1 A
2 2 A
3 3 A
4 2 B
5 3 B
6 4 B
7 3 C
8 4 C
9 5 C
10 4 D
11 5 D
12 6 D
The following code works but it is extremely slow with wide ranges:
df<-data.frame()
for(i in 1:dim(a)[1]){
s<-seq(a[i,1],a[i,2])
df<-rbind(df,data.frame(s,rep(a[i,3],length(s))))
}
colnames(df)<-c("V1","V2")
How can I speed this up?
You can try data.table
library(data.table)
setDT(a)[, start:end, by = group]
which gives
group V1
1: A 1
2: A 2
3: A 3
4: B 2
5: B 3
6: B 4
7: C 3
8: C 4
9: C 5
10: D 4
11: D 5
12: D 6
Obviously this would only work if you have one row per group, which it seems you have here.
If you want a very fast solution in base R, you can manually create the data.frame in two steps:
Use mapply to create a list of your ranges from "start" to "end".
Use rep + lengths to repeat the "groups" column to the expected number of rows.
The base R approach shared here won't depend on having only one row per group.
Try:
temp <- mapply(":", a[["start"]], a[["end"]], SIMPLIFY = FALSE)
data.frame(group = rep(a[["group"]], lengths(temp)),
values = unlist(temp, use.names = FALSE))
If you're doing this a lot, just put it in a function:
myFun <- function(indf) {
temp <- mapply(":", indf[["start"]], indf[["end"]], SIMPLIFY = FALSE)
data.frame(group = rep(indf[["group"]], lengths(temp)),
values = unlist(temp, use.names = FALSE))
}
Then, if you want some sample data to try it with, you can use the following as sample data:
set.seed(1)
a <- data.frame(start=1:4, end=sample(5:10, 4, TRUE), group=c("A","B","C","D"))
x <- do.call(rbind, replicate(1000, a, FALSE))
y <- do.call(rbind, replicate(100, x, FALSE))
Note that this does seem to slow down as the number of different unique values in "group" increases.
(In other words, the "data.table" approach will make the most sense in general. I'm just sharing a possible base R alternative that should be considerably faster than your existing approach.)

Finding rows which match between 2 dataframes, and the index of them in R

I have 2 dataframes. First (and I know how to do this) I want to find which rows (the whole row) match between the 2 dataframes. So I can create a column in A which tells me if that entire row is in B. However, the part I don't know how to do is to find which indices in B it would be.
TL DR; I need to create a new column in A, which tells me FALSE if the whole row isn't in B, or instead give me the index of where that row is in B.
a = as.data.frame(matrix(data = 1:10,nrow=5))
b = as.data.frame(matrix(data = c(1:5,10,7,6,9,8), nrow=5))
set.seed(02138)
b = b[sample(nrow(b)),]
rownames(b) = 1:nrow(b)
a_ = do.call("paste", a[,1:2])
b_ = do.call("paste", b[,1:2])
# Gets me TRUE/FALSE of whether there is a complete row-wise match
a$InB = a_ %in% b_
# Gets me which rows they are in b
b[b_ %in% a_,]
# Now is where I need help combining this
# Expected output
> a$InB = temp
> a
V1 V2 InB
1 1 6 FALSE
2 2 7 3
3 3 8 FALSE
4 4 9 5
5 5 10 FALSE
You can add this:
a$InB[a$InB] <- as.character(which(b_ %in% a_))
a
# V1 V2 InB
#1 1 6 FALSE
#2 2 7 3
#3 3 8 FALSE
#4 4 9 5
#5 5 10 FALSE

R read.table loops row column entries to next row

This is the first time I encountered this problem using read.table: For row entries with very large number of columns, read.table loops the column entries into the next rows.
I have a .txt file with rows of variable and unequal length. For reference this is the .txt file I am reading: http://www.broadinstitute.org/gsea/msigdb/download_file.jsp?filePath=/resources/msigdb/4.0/c5.bp.v4.0.symbols.gmt
Here is my code:
tabsep <- gsub("\\\\t", "\t", "\\t")
MSigDB.collection = read.table(fileName, header = FALSE, fill = TRUE, as.is = TRUE, sep = tabsep)
Partial output: first columns
V1 V2 V3 V4 V5 V6
1 TRNA_PROCESSING http://www.broadinstitute.org/gsea/msigdb/cards/TRNA_PROCESSING ADAT1 TRNT1 FARS2
2 REGULATION_OF_BIOLOGICAL_QUALITY http://www.broadinstitute.org/gsea/msigdb/cards/REGULATION_OF_BIOLOGICAL_QUALITY DLC1 ALS2 SLC9A7
3 DNA_METABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/DNA_METABOLIC_PROCESS XRCC5 XRCC4 RAD51C
4 AMINO_SUGAR_METABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/AMINO_SUGAR_METABOLIC_PROCESS UAP1 CHIA GNPDA1
5 BIOPOLYMER_CATABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/BIOPOLYMER_CATABOLIC_PROCESS BTRC HNRNPD USE1
6 RNA_METABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/RNA_METABOLIC_PROCESS HNRNPF HNRNPD SYNCRIP
7 INTS6 LSM5 LSM4 LSM3 LSM1
8 CRK
9 GLUCAN_METABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/GLUCAN_METABOLIC_PROCESS GCK PYGM GSK3B
10 PROTEIN_POLYUBIQUITINATION http://www.broadinstitute.org/gsea/msigdb/cards/PROTEIN_POLYUBIQUITINATION ERCC8 HUWE1 DZIP3
...
Partial output: last columns
V403 V404 V405 V406 V407 V408 V409 V410 V411 V412 V413 V414 V415 V416 V417 V418 V419 V420 V421
1
2 CALCA CALCB FAM107A CDK11A RASGRP4 CDK11B SYN3 GP1BA TNN ENO1 PTPRC MTL5 ISOC2 RHAG VWF GPI HPX SLC5A7 F2R
3
4
5
6 IRF2 IRF3 SLC2A4RG LSM6 XRCC6 INTS1 HOXD13 RP9 INTS2 ZNF638 INTS3 ZNF254 CITED1 CITED2 INTS9 INTS8 INTS5 INTS4 INTS7
7 POU1F1 TCF7L2 TNFRSF1A NPAS2 HAND1 HAND2 NUDT21 APEX1 ENO1 ERF DTX1 SOX30 CBY1 DIS3 SP1 SP2 SP3 SP4 NFIC
8
9
10
For instance, column entries for row 6 gets looped to fill row 7 and row 8. I seem to only this problem for row entries with very large number of columns. This occurs for other .txt files as well but it breaks at different column numbers. I inspected all the row entries at where the break happens and there are no unusual characters in the entries (they are all standard upper case gene symbols).
I have tried both read.table and read.delim with the same result. If I convert the .txt file to .csv first and use the same code, I do not have this problem (see below for the equivalent output). But I don't want to convert each file first .csv and really I just want to understand what is going on.
Correct output if I convert to .csv file:
MSigDB.collection = read.table(fileName, header = FALSE, fill = TRUE, as.is = TRUE, sep = ",")
V1 V2 V3 V4 V5 V6
1 TRNA_PROCESSING http://www.broadinstitute.org/gsea/msigdb/cards/TRNA_PROCESSING ADAT1 TRNT1 FARS2 METTL1
2 REGULATION_OF_BIOLOGICAL_QUALITY http://www.broadinstitute.org/gsea/msigdb/cards/REGULATION_OF_BIOLOGICAL_QUALITY DLC1 ALS2 SLC9A7 PTGS2
3 DNA_METABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/DNA_METABOLIC_PROCESS XRCC5 XRCC4 RAD51C XRCC3
4 AMINO_SUGAR_METABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/AMINO_SUGAR_METABOLIC_PROCESS UAP1 CHIA GNPDA1 GNE
5 BIOPOLYMER_CATABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/BIOPOLYMER_CATABOLIC_PROCESS BTRC HNRNPD USE1 RNASEH1
6 RNA_METABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/RNA_METABOLIC_PROCESS HNRNPF HNRNPD SYNCRIP MED24
7 GLUCAN_METABOLIC_PROCESS http://www.broadinstitute.org/gsea/msigdb/cards/GLUCAN_METABOLIC_PROCESS GCK PYGM GSK3B EPM2A
8 PROTEIN_POLYUBIQUITINATION http://www.broadinstitute.org/gsea/msigdb/cards/PROTEIN_POLYUBIQUITINATION ERCC8 HUWE1 DZIP3 DDB2
9 PROTEIN_OLIGOMERIZATION http://www.broadinstitute.org/gsea/msigdb/cards/PROTEIN_OLIGOMERIZATION SYT1 AASS TP63 HPRT1
To elaborate on my comment...
From the help page to read.table:
The number of data columns is determined by looking at the first five lines of input (or the whole file if it has less than five lines), or from the length of col.names if it is specified and is longer. This could conceivably be wrong if fill or blank.lines.skip are true, so specify col.names if necessary (as in the ‘Examples’).
To work around this with unknown datasets, use count.fields to determine the number of separators in a file, and use that to create col.names for read.table to use:
x <- max(count.fields("~/Downloads/c5.bp.v4.0.symbols.gmt", "\t"))
Names <- paste("V", sequence(x), sep = "")
y <- read.table("~/Downloads/c5.bp.v4.0.symbols.gmt", col.names=Names, sep = "\t", fill = TRUE)
Inspect the first few lines. I'll leave the actual full inspection to you.
y[1:6, 1:10]
# V1
# 1 TRNA_PROCESSING
# 2 REGULATION_OF_BIOLOGICAL_QUALITY
# 3 DNA_METABOLIC_PROCESS
# 4 AMINO_SUGAR_METABOLIC_PROCESS
# 5 BIOPOLYMER_CATABOLIC_PROCESS
# 6 RNA_METABOLIC_PROCESS
# V2 V3 V4
# 1 http://www.broadinstitute.org/gsea/msigdb/cards/TRNA_PROCESSING ADAT1 TRNT1
# 2 http://www.broadinstitute.org/gsea/msigdb/cards/REGULATION_OF_BIOLOGICAL_QUALITY DLC1 ALS2
# 3 http://www.broadinstitute.org/gsea/msigdb/cards/DNA_METABOLIC_PROCESS XRCC5 XRCC4
# 4 http://www.broadinstitute.org/gsea/msigdb/cards/AMINO_SUGAR_METABOLIC_PROCESS UAP1 CHIA
# 5 http://www.broadinstitute.org/gsea/msigdb/cards/BIOPOLYMER_CATABOLIC_PROCESS BTRC HNRNPD
# 6 http://www.broadinstitute.org/gsea/msigdb/cards/RNA_METABOLIC_PROCESS HNRNPF HNRNPD
# V5 V6 V7 V8 V9 V10
# 1 FARS2 METTL1 SARS AARS THG1L SSB
# 2 SLC9A7 PTGS2 PTGS1 MPV17 SGMS1 AGTR1
# 3 RAD51C XRCC3 XRCC2 XRCC6 ISG20 PRIM1
# 4 GNPDA1 GNE CSGALNACT1 CHST2 CHST4 CHST5
# 5 USE1 RNASEH1 RNF217 ISG20 CDKN2A CPA2
# 6 SYNCRIP MED24 RORB MED23 REST MED21
nrow(y)
# [1] 825
Here's a minimal example for those who don't want to download the other file to try it out.
Create a 6-line CSV file where the last line has more fields than the first 5 lines and try to use read.table on it:
cat("1,2,3,4", "1,2,3,4", "1,2,3,4", "1,2,3,4",
"1,2,3,4", "1,2,3,4,5", file = "test1.txt",
sep = "\n")
read.table("test1.txt", header = FALSE, sep = ",", fill = TRUE)
# V1 V2 V3 V4
# 1 1 2 3 4
# 2 1 2 3 4
# 3 1 2 3 4
# 4 1 2 3 4
# 5 1 2 3 4
# 6 1 2 3 4
# 7 5 NA NA NA
Note the difference with if the longest line were in the first five lines of the file:
cat("1,2,3,4", "1,2,3,4,5", "1,2,3,4", "1,2,3,4",
"1,2,3,4", "1,2,3,4", file = "test2.txt",
sep = "\n")
read.table("test2.txt", header = FALSE, sep = ",", fill = TRUE)
# V1 V2 V3 V4 V5
# 1 1 2 3 4 NA
# 2 1 2 3 4 5
# 3 1 2 3 4 NA
# 4 1 2 3 4 NA
# 5 1 2 3 4 NA
# 6 1 2 3 4 NA
To fix the problem, we use count.fields which returns a vector of the number of fields detected in each line. We take the max from that and pass it on to a col.names argument for read.table.
x <- count.fields("test1.txt", sep=",")
x
# [1] 4 4 4 4 4 5
read.table("test.txt", header = FALSE, sep = ",", fill = TRUE,
col.names = paste("V", sequence(max(x)), sep = ""))
# V1 V2 V3 V4 V5
# 1 1 2 3 4 NA
# 2 1 2 3 4 NA
# 3 1 2 3 4 NA
# 4 1 2 3 4 NA
# 5 1 2 3 4 NA
# 6 1 2 3 4 5

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