Read.table error in R - r

I'm using R to read a text file and then subsequently manipulate it.
The input file has 22 columns. This is what the first column looks like :
NAME LENGTH A C D E F G H I K L M N P Q R S T V W Y
I am currently using:
read.table("filename", stringsAsFactors=FALSE)
to input the file. When I run the same, I get this warning:
Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, :
line 2 did not have 23 elements
Not sure where I am going wrong. I'm new to R and I would really appreciate your help. I've tried to make sure this isn't a repost, but if it is, please do link me to the original.

Assuming the text file looks like this:
NAME LENGTH A C D E F G H I K L M N P Q R S T V W Y
ape:APE_0001 242 15 0 1 12 10 18 2 27 9 43 7 2 8 3 5 25 15 24 3 12
ape:APE_0002 113 7 1 6 6 1 12 3 4 10 16 4 2 4 0 10 3 5 9 4 5
ape:APE_0004 305 24 2 5 8 9 25 4 36 12 43 8 11 14 2 12 20 21 27 9 12
and is called 'dat.txt' and stored in your working directory, this should just work:
dat <- read.table("dat.txt", stringsAsFactors=FALSE, header=TRUE)
# to give:
dat
NAME LENGTH A C D E F G H I K L M N P Q R S T V W Y
1 ape:APE_0001 242 15 0 1 12 10 18 2 27 9 43 7 2 8 3 5 25 15 24 3 12
2 ape:APE_0002 113 7 1 6 6 1 12 3 4 10 16 4 2 4 0 10 3 5 9 4 5
3 ape:APE_0004 305 24 2 5 8 9 25 4 36 12 43 8 11 14 2 12 20 21 27 9 12
Since that doesn't appear to be working for you, there might be something odd and invisible going on in your text file, hidden characters, etc.
Assuming your text file isn't enormous, one workaround would be to open a new R script in RStudio then type in
dat <- read.table(stringsAsFactors=FALSE, header=TRUE, text = "")
And then copy and paste all the text in your text file between the "" in the line above, without any changes to line breaks or formatting, and then select all and send it to the console.
For the example in your comment that would look like this:
dat <- read.table(header=TRUE, stringsAsFactors=FALSE, text = "NAME LENGTH A C D E F G H I K L M N P Q R S T V W Y
ape:APE_0001 242 15 0 1 12 10 18 2 27 9 43 7 2 8 3 5 25 15 24 3 12
ape:APE_0002 113 7 1 6 6 1 12 3 4 10 16 4 2 4 0 10 3 5 9 4 5
ape:APE_0004 305 24 2 5 8 9 25 4 36 12 43 8 11 14 2 12 20 21 27 9 12")
If that's not practical or possible, post a link to your text file in your question (like this: http://temp-share.com/show/dPf3a6oHW deleted automatically after 45 Days) so others can have a look.

Related

R : Change name of variable using for loop

I have a data, and vectors conatin name of variables, from these vectorsi calculate the sum of variables contained in the vector and i want to put the result in a new variables that have diffrent names
let say i have three vectors
>data
Name A B C D E
r1 1 5 12 21 15
r2 2 4 7 10 9
r3 5 15 6 9 6
r4 7 8 0 7 18
And i have these vectors that are generated using for loop that are in variable vec
V1 <- ("A","B","C")
V2 <- ("B","D")
V3 <- ("D","E")
Edit 1 :
These vector are generated using for loop and i don't know the vectors that will be generated or the elemnts contained in these vector , here i'm giving just an example , i want to calculate the sum of variables in each vector and make the result in new variable in my data frame
The issue is don't know how to give new name to variables created (that contains the sum of each vector)
data$column[j] <- rowSums(all_data_Second_program[,vec])
j <- j+1
To obtain this result for example
Name A B C Column1 D Column2 E Column3
r1 1 5 12 18 21 26 15 36
r2 2 4 7 13 10 14 9 19
r3 5 15 6 26 9 24 6 15
r4 7 8 0 15 7 15 18 25
But i didn't obtain this result
Please tell me if you need any more informations or clarifications
Can you tell me please how to that
Put the vectors in a list and then you can use rowSums in lapply -
list_vec <- list(c("A","B","C"), c("B","D"), c("D","E"))
new_cols <- paste0('Column', seq_along(list_vec))
data[new_cols] <- lapply(list_vec, function(x) rowSums(data[x]))
data
# Name A B C D E Column1 Column2 Column3
#1 r1 1 5 12 21 15 18 26 36
#2 r2 2 4 7 10 9 13 14 19
#3 r3 5 15 6 9 6 26 24 15
#4 r4 7 8 0 7 18 15 15 25
We may use a for loop
for(i in 1:3) {
data[[paste0('Column', i)]] <- rowSums(data[get(paste0('V', i))],
na.rm = TRUE)
}
-output
> data
Name A B C D E Column1 Column2 Column3
1 r1 1 5 12 21 15 18 26 36
2 r2 2 4 7 10 9 13 14 19
3 r3 5 15 6 9 6 26 24 15
4 r4 7 8 0 7 18 15 15 25

R - Issues while calling a user-defined function

I have the following dataframe named "dataset"
> dataset
V1 V2 V3 V4 V5 V6 V7
1 A 29 27 0 14 21 163
2 W 70 40 93 63 44 1837
3 E 11 1 11 49 17 315
4 S 20 59 36 23 14 621
5 C 12 7 48 24 25 706
6 B 14 8 78 27 17 375
7 G 12 7 8 4 4 257
8 T 0 0 0 0 0 0
9 N 32 6 9 14 17 264
10 R 28 46 49 55 38 608
11 O 12 2 8 12 11 450
I have two helper functions as below
get_A <- function(p){
return(data.frame(Scorecard = p,
Results = dataset[nrow(dataset),(p+1)]))
} #Pulls the value from the last row for a given value of (p and offset by 1)
get_P <- function(p){
return(data.frame(Scorecard= p,
Results = dataset[p,ncol(dataset)]))
} #Pulls the value from the last column for a given value of p
I have the following dataframe on which I need to run the above helper functions. There will be NAs because I'm reading this "data_sub" dataframe from an excel file which can have unequal rows for the two columns.
> data_sub
Key_P Key_A
1 2 1
2 3 3
3 4 5
4 NA NA
When I call the helper functions, I get some strange results as shown below:
> get_P(data_sub[complete.cases(data_sub$Key_P),]$Key_P)
Scorecard Results
1 2 1837
2 3 315
3 4 621
> get_A(data_sub[complete.cases(data_sub$Key_A),]$Key_A)
Scorecard Results.V2 Results.V4 Results.V6
1 1 12 8 11
2 3 12 8 11
3 5 12 8 11
Warning message:
In data.frame(Scorecard = p, Results = dataset[nrow(dataset), (p + :
row names were found from a short variable and have been discarded
The call to the get_P() helper function is working the way I want. I'm getting the "Results" for each non-NA value in data_sub$Key_P as a dataframe.
But the call to the get_A() helper function is giving strange results and also a warning.I was expecting it to give a similar dataframe as given the call to get_P(). Why is this happening and how can I make get_A() to give the correct dataframe? Basically, the output of this should be
Scorecard Results
1 1 12
2 3 8
3 5 11
I found this link related to the warning but it's unhelpful in solving my issue.
The following works
get_P <- function(df, data_sub) {
data_sub <- data_sub[complete.cases(data_sub), ]
data.frame(
Scorecard = data_sub$Key_P,
Results = df[data_sub$Key_P, ncol(df)])
}
get_P(df, data_sub)
# Scorecard Results
#1 2 1837
#2 3 315
#3 4 621
get_A <- function(df, data_sub) {
data_sub <- data_sub[complete.cases(data_sub), ];
data.frame(
Scorecard = data_sub$Key_A,
Results = as.numeric(df[nrow(df), data_sub$Key_A + 1]))
}
get_A(df, data_sub)
# Scorecard Results
#1 1 12
#2 3 8
#3 5 11
To avoid the warning, we need to strip rownames with as.numeric in get_A.
Another tip: It's better coding practice to make get_P and get_A a function of both df and data_sub to avoid global variables.
Sample data
df <- read.table(text =
" V1 V2 V3 V4 V5 V6 V7
1 A 29 27 0 14 21 163
2 W 70 40 93 63 44 1837
3 E 11 1 11 49 17 315
4 S 20 59 36 23 14 621
5 C 12 7 48 24 25 706
6 B 14 8 78 27 17 375
7 G 12 7 8 4 4 257
8 T 0 0 0 0 0 0
9 N 32 6 9 14 17 264
10 R 28 46 49 55 38 608
11 O 12 2 8 12 11 450", header = T, row.names = 1)
data_sub <- read.table(text =
" Key_P Key_A
1 2 1
2 3 3
3 4 5
4 NA NA", header = T, row.names = 1)

Creating Groups by Matching Values of Different Columns

I would like to create groups from a base by matching values.
I have the following data table:
now<-c(1,2,3,4,24,25,26,5,6,21,22,23)
before<-c(0,1,2,3,23,24,25,4,5,0,21,22)
after<-c(2,3,4,5,25,26,0,6,0,22,23,24)
df<-as.data.frame(cbind(now,before,after))
which reproduces the following data:
now before after
1 1 0 2
2 2 1 3
3 3 2 4
4 4 3 5
5 24 23 25
6 25 24 26
7 26 25 0
8 5 4 6
9 6 5 0
10 21 0 22
11 22 21 23
12 23 22 24
I would like to get:
now before after group
1 1 0 2 A
2 2 1 3 A
3 3 2 4 A
4 4 3 5 A
5 5 4 6 A
6 6 5 0 A
7 21 0 22 B
8 22 21 23 B
9 23 22 24 B
10 24 23 25 B
11 25 24 26 B
12 26 25 0 B
I would like to reach the answer to this without using a "for" loop becouse the real data is too large.
Any you could provide will be appreciated.
Here is one way. It is hard to avoid a for-loop as this is quite a tricky algorithm. The objection to them is often on the grounds of elegance rather than speed, but sometimes they are entirely appropriate.
df$group <- seq_len(nrow(df)) #assign each row to its own group
stop <- FALSE #indicates convergence
while(!stop){
pre <- df$group #group column at start of loop
for(i in seq_len(nrow(df))){
matched <- which(df$before==df$now[i] | df$after==df$now[i]) #check matches in before and after columns
group <- min(df$group[i], df$group[matched]) #identify smallest group no of matching rows
df$group[i] <- group #set to smallest group
df$group[matched] <- group #set to smallest group
}
if(identical(df$group, pre)) stop <- TRUE #stop if no change
}
df$group <- LETTERS[match(df$group, sort(unique(df$group)))] #convert groups to letters
#(just use match(...) to keep them as integers - e.g. if you have more than 26 groups)
df <- df[order(df$group, df$now),] #reorder as required
df
now before after group
1 1 0 2 A
2 2 1 3 A
3 3 2 4 A
4 4 3 5 A
8 5 4 6 A
9 6 5 0 A
10 21 0 22 B
11 22 21 23 B
12 23 22 24 B
5 24 23 25 B
6 25 24 26 B
7 26 25 0 B

loop in R to subset from list object ( extract multiple tables from excel sheets)

I need to extract separate tables from each excel sheet and have them as a list object. I have two lists : "allsheets" contains 38 sheets and each of sheets includes at least 2 tables, and "dataRowMeta" contains information about which rows are relevant for each table. For example,
a1 <- data.frame(y1=c(1:15),y2=c(6:20))
a2 <- data.frame(y1=c(3:18),y2=c(2:17))
allsheets <- list(a1, a2)
d1<- data.frame(starthead=c(1,9),endhead=c(2,10),startdata =c(3,11),
enddata = c(7,14),footer = c(8,15))
d2<- data.frame(starthead=c(1,10),endhead=c(2,11),startdata =c(3,12),
enddata = c(8,15),footer = c(9,16))
dataRowMeta <- list(d1,d2)
[[1]]
y1 y2
1 1 6
2 2 7
3 3 8
4 4 9
5 5 10
6 6 11
7 7 12
8 8 13
9 9 14
10 10 15
11 11 16
12 12 17
13 13 18
14 14 19
15 15 20
[[2]]
y1 y2
1 3 2
2 4 3
3 5 4
4 6 5
5 7 6
6 8 7
7 9 8
8 10 9
9 11 10
10 12 11
11 13 12
12 14 13
13 15 14
14 16 15
15 17 16
16 18 17
and here is dataRowMeta :
[[1]]
starthead endhead startdata enddata footer
1 1 2 3 7 8
2 9 10 11 14 15
[[2]]
starthead endhead startdata enddata footer
1 1 2 3 8 9
2 10 11 12 15 16
I've tried to write a loop function which would subset each sheet according to dataRowMeta, but failed to get a desired output.
I am getting an error
Error in sheet[[a[m]:b[m], ]] : incorrect number of subscripts
I guess that's because I am iterating over list, not matrices...but how to tell R to subset list in this case?
So I need 1st and 4th columns of dataRowMeta(starthead and enddata) as "start" and "end" id rows of future tables.
tables <- function(allsheets,dataRowMeta){
for(i in 1 : length(dataRowMeta)){
for (j in 1 : nrow(dataRowMeta[[i]])){
a <-""
b <- ""
a <- dataRowMeta[[i]][j:j,1]
b <- dataRowMeta[[i]][j:j,4]
for (k in 1 : length(allsheets)){
sheet <- allsheets[k]
for ( m in 1 : length(a)){
tbl <- sheet[[a[m]:b[m],]]
}
}
}
}}
Desired output : I have this for the first element of the first list(sheet1):
sheet1 <- allsheets[[1]]
tmp1 <- sheet1[dataRowMeta[[1]][1:1,1] :dataRowMeta[[1]][1:1,4] ,]
> tmp1
y1 y2
1 1 6
2 2 7
3 3 8
4 4 9
5 5 10
6 6 11
7 7 12
And need a loop which would do it for all sheets. Please help me to figure out how to get it. Thank you!

R: subset a data frame based on conditions from another data frame

Here is a problem I am trying to solve. Say, I have two data frames like the following:
observations <- data.frame(id = rep(rep(c(1,2,3,4), each=5), 5),
time = c(rep(1:5,4), rep(6:10,4), rep(11:15,4), rep(16:20,4), rep(21:25,4)),
measurement = rnorm(100,5,7))
sampletimes <- data.frame(location = letters[1:20],
id = rep(1:4,5),
time1 = rep(c(2,7,12,17,22), each=4),
time2 = rep(c(4,9,14,19,24), each=4))
They both contain a column named id, which links the data frames. I want to have the measurements from observationss for whichtimeis betweentime1andtime2from thesampletimesdata frame. Additionally, I'd like to connect the appropriatelocation` to each measurement.
I have successfully done this by converting my sampletimes to a wide format (i.e. all the time1 and time2 information in one row per entry for id), merging the two data frames by the id variable, and using conditional statements to take only instances when the time falls between at least one of the time intervals in the row, and then assigning location to the appropriate measurement.
However, I have around 2 million rows in observations and doing this takes a really long time. I'm looking for a better way where I can keep the data in long format. The example dataset is very simple, but in reality, my data contains variable numbers of intervals and locations per id.
For our example, the data frame I would hope to get back would be as follows:
id time measurement letters[1:20]
1 3 10.5163892 a
2 3 5.5774119 b
3 3 10.5057060 c
4 3 14.1563179 d
1 8 2.2653761 e
2 8 -1.0905546 f
3 8 12.7434161 g
4 8 17.6129261 h
1 13 10.9234673 i
2 13 1.6974481 j
3 13 -0.3664951 k
4 13 13.8792198 l
1 18 6.5038847 m
2 18 1.2032935 n
3 18 15.0889469 o
4 18 0.8934357 p
1 23 3.6864527 q
2 23 0.2404074 r
3 23 11.6028766 s
4 23 20.7466908 t
Here's a proposal with merge:
# merge both data frames
dat <- merge(observations, sampletimes, by = "id")
# extract valid rows
dat2 <- dat[dat$time > dat$time1 & dat$time < dat$time2, seq(4)]
# sort
dat2[order(dat2$time, dat2$id), ]
The result:
id time measurement location
11 1 3 7.086246 a
141 2 3 6.893162 b
251 3 3 16.052627 c
376 4 3 -6.559494 d
47 1 8 11.506810 e
137 2 8 10.959782 f
267 3 8 11.079759 g
402 4 8 11.082015 h
83 1 13 5.584257 i
218 2 13 -1.714845 j
283 3 13 -11.196792 k
418 4 13 8.887907 l
99 1 18 1.656558 m
234 2 18 16.573179 n
364 3 18 6.522298 o
454 4 18 1.005123 p
125 1 23 -1.995719 q
250 2 23 -6.676464 r
360 3 23 10.514282 s
490 4 23 3.863357 t
Not efficient , but do the job :
subset(merge(observations,sampletimes), time > time1 & time < time2)
id time measurement location time1 time2
11 1 3 3.180321 a 2 4
47 1 8 6.040612 e 7 9
83 1 13 -5.999317 i 12 14
99 1 18 2.689414 m 17 19
125 1 23 12.514722 q 22 24
137 2 8 4.420679 f 7 9
141 2 3 11.492446 b 2 4
218 2 13 6.672506 j 12 14
234 2 18 12.290339 n 17 19
250 2 23 12.610828 r 22 24
251 3 3 8.570984 c 2 4
267 3 8 -7.112291 g 7 9
283 3 13 6.287598 k 12 14
360 3 23 11.941846 s 22 24
364 3 18 -4.199001 o 17 19
376 4 3 7.133370 d 2 4
402 4 8 13.477790 h 7 9
418 4 13 3.967293 l 12 14
454 4 18 12.845535 p 17 19
490 4 23 -1.016839 t 22 24
EDIT
Since you have more than 5 millions rows, you should give a try to a data.table solution:
library(data.table)
OBS <- data.table(observations)
SAM <- data.table(sampletimes)
merge(OBS,SAM,allow.cartesian=TRUE,by='id')[time > time1 & time < time2]

Resources