I am applying this function to my dataset column DL1 on another vector as below and receiving the results expected
table(df$DL1[df$DL1 %in% undefined_dl_codes])
Result:
0 10 30 3B 4 49 54 5A 60 7 78 8 90
24 366 4 3 665 40 1 1 14 8 4 87 1
however I do have columns DL2, DL3 and DL4 which have same data, how can I apply the function to multiple columns and receive the result of all. I would need to go through all 4 required columns and receive 1 result as summary.
Any help highly appreciated!
May not be the best of the methods, however you could do the following
table(c(df$DL1[df$DL1 %in% undefined_dl_codes],
df$DL2[df$DL2 %in% undefined_dl_codes],
df$DL3[df$DL3 %in% undefined_dl_codes],
df$DL4[df$DL4 %in% undefined_dl_codes]
)
)
Using Raghuveer solution I further simplified,
attach(df)
table(c(DL1,DL2,DL3,DL4)[c(DL1,DL2,DL3,DL4) %in% undefined_dl_codes])
detach(df)
Related
This question already has answers here:
Convert *some* column classes in data.table
(2 answers)
Closed 4 years ago.
I am trying to write a "for" loop that iterates through each column in a data.table and return a frequency table. However, I keep getting an error saying:
library(datasets)
data(cars)
cars <- as.data.table(cars)
for (i in names(cars)){
print(table(cars[,i]))
}
Error in `[.data.table`(cars, , i) :
j (the 2nd argument inside [...]) is a single symbol but column name 'i' is not found. Perhaps you intended DT[, ..i]. This difference to data.frame is deliberate and explained in FAQ 1.1.
When I use each column individually like below, I do not have any problem:
> table(cars[,dist])
2 4 10 14 16 17 18 20 22 24 26 28 32 34 36 40 42 46 48 50 52 54 56 60 64 66
1 1 2 1 1 1 1 2 1 1 4 2 3 3 2 2 1 2 1 1 1 2 2 1 1 1
68 70 76 80 84 85 92 93 120
1 1 1 1 1 1 1 1 1
My data is quite large (8921483x52), that is why I want to use the "for" loop and run everything at once then look at the result.
I included the cars dataset (which is easier to run) to demonstrate my code.
If I convert the dataset to data.frame, there is no problem running the "for" loop. But I just want to know why this does not work with data.table because I am learning it, which work better with large dataset in my belief.
If by chance, someone saw a post with an answer already, please let me know because I have been trying for several hours to look for one.
Some solution found here
My personal preference is the apply function though
library(datasets)
data(cars)
cars <- as.data.table(cars)
apply(cars,2,table)
To make your loop work you tweak the i
library(datasets)
data(cars)
cars <- as.data.table(cars)
for (i in names(cars)){
print(table(cars[,(i) := as.character(get(i))]))
}
I have a dataframe as follows
Me You They Him She
1 4 6 3 233
82 0 2 4 122
98 2 5 2 99
I want to get a new dataframe which only contains those columns where the colMeans are >30 so the result should look like
Me She
1 233
82 122
98 99
I tried something like
dfNew<-subset(df,colMeans(df[, 1:ncol(df)]>30))
but got the error
Error in subset.data.frame(df[, 1:ncol(df)]> :
'subset' must be logical
Clearly don't know what Im doing.
try this:
df[,colMeans(df)>30]
I Think this is something that you are looking for
This step is just me creating your data.
Me <- c(1,82,98)
You <- c(4,0,2)
They <- c(6,5,5)
Him <- c(3,4,2)
She <- c(233,122,99)
df <- as.data.frame(cbind(Me, You, They, Him, She))
This is what you want.
df[, sapply(df, mean) > 60]
Question:
I am a little stumped as to how I can batch process as.numeric() (or any other function for that matter) for columns in a list of data frames.
I understand that I can view specific data frames or colunms within this list by using:
> my.list[[1]]
# or columns within this data frame using:
> my.list[[1]][1]
But my trouble comes when I try to apply this into an lapply() function to change all of the data from integer to numeric.
# Example of what I am trying to do
> my.list[[each data frame in list]][each column in data frame] <-
as.numberic(my.list[[each data frame in list]][each column in data frame])
If you can assist me in any way, or know of any resources that can help me out I would appreciate it.
Background:
My data frames are structured as the below example, where I have 5 habitat types and information on how much area an individual species home range extends to n :
# Example data
spp.1.data <- data.frame(Habitat.A = c(100,45,0,9,0), Habitat.B = c(0,0,203,45,89), Habitat.C = c(80,22,8,9,20), Habitat.D = c(8,59,77,83,69), Habitat.E = c(23,15,99,0,10))
I have multiple data frames with the above structure which I have assigned to a list object:
all.spp.data <- list(spp.1.data, spp.2.data, spp.1.data...n)
I am then trying to coerce all data frames to as.numeric() so I can create data frames of % habitat use i.e:
# data, which is now numeric as per Phil's code ;)
data.numeric <- lapply(data, function(x) {
x[] <- lapply(x, as.numeric)
x
})
> head(data.numeric[[1]])
Habitat.A Habitat.B Habitat.C Habitat.D Habitat.E
1 100 0 80 8 23
2 45 0 22 59 15
3 0 203 8 77 99
4 9 45 9 83 0
5 0 89 20 69 10
EDIT: I would like to sum every row, in all data frames
# Add row at the end of each data frame populated by rowSums()
f <- function(i){
data.numeric[[i]]$Sums <- rowSums(data.numeric[[i]])
data.numeric[[i]]
}
data.numeric.SUM <- lapply(seq_along(data.numeric), f)
head(data.numeric.SUM[[1]])
Habitat.A Habitat.B Habitat.C Habitat.D Habitat.E Sums
1 100 0 80 8 23 211
2 45 0 22 59 15 141
3 0 203 8 77 99 387
4 9 45 9 83 0 146
5 0 89 20 69 10 188
EDIT: This is the code I used to convert values within the data frames to % habitat used
# Used Phil's logic to convert all numbers in percentages
data.numeric.SUM.perc <- lapply(data.numeric.SUM,
function(x) {
x[] <- (x[]/x[,6])*100
x
})
Perc.Habitat.A Perc.Habitat.B Perc.Habitat.C Perc.Habitat.D Perc.Habitat.E
1 47 32 0 6 0
2 0 0 52 31 47
3 38 16 2 6 11
4 4 42 20 57 37
5 11 11 26 0 5
6 100 100 100 100 100
This is still not the most condensed way to do this, but it did the trick for me.
Thank you, Phil, Val and Leo P, for helping with this problem.
I'd do this a bit more explicitly:
all.spp.data <- lapply(all.spp.data, function(x) {
x[] <- lapply(x, as.numeric)
x
})
As a personal preference, this clearly conveys to me that I'm looping over each column in a data frame, and looping over each data frame in a list.
If you really want to do it all with lapply, here's a way to go:
lapply(all.spp.data,function(x) do.call(cbind,lapply(1:nrow(x),function(y) as.numeric(x[,y]))))
This uses a nested lapply call. The first one references the single data.frames to x. The second one references the column index for each x to y. So in the end I can reference each column by x[,y].
Since everything will be split up in single vectors, I'm calling do.call(cbind, ... ) to bring it back to a matrix. If you prefer you could add data.frame() around it to bring it back into the original type.
I have two data.frames, one with genotype counts and one with a number that I need to normalize my counts from the first dataset.
countsdata=data.frame(genotype1=rep(c(10,20,30,40),each=1),
genotype2=rep(c(100,200,300,400),each=1),
genotype3=rep(c(40,50,60,70),each=1),
genotype4=rep(c(40,50,60,70),each=1)
)
coldata = data.frame(Group =c('genotype1', 'genotype2', 'genotype3', 'genotype4'),
Treatment = rep(c("control","treated"),each = 2),
Norm=rep(c(1,2,5,5)))
I made sure my variables don't have factors
factorsCharacter <- function(d) modifyList(d, lapply(d[, sapply(d, is.factor)],
as.character))
coldata=factorsCharacter(coldata)
Then I see that lapply loops through my counts, one column at the time and through my coldata that contains the normalization value (Norm). All is looking good, until I combined the two action in the same step
> lapply(coldata['Group'],function(group_i){group_i})
$Group
[1] "genotype1" "genotype2" "genotype3" "genotype4"
> lapply(coldata['Group'],function(group_i){countsdata[,group_i]})
$Group
genotype1 genotype2 genotype3 genotype4
1 10 100 40 40
2 20 200 50 50
3 30 300 60 60
4 40 400 70 70
> lapply(coldata['Group'],function(group_i){as.integer(coldata[coldata$Group==group_i,'Norm'])})
$Group
[1] 1 2 5 5
> lapply(coldata['Group'],function(group_i){
+ countsdata[,group_i]/as.integer(coldata[coldata$Group==group_i,'Norm'])
+ })
$Group
genotype1 genotype2 genotype3 genotype4
1 10 100 40 40
2 10 100 25 25
3 6 60 12 12
4 8 80 14 14
Here the result is not what I was expecting (dividing each column by its normalization number). After further inspection I noticed it's normalizing by rows, in other words it's normalizing across different columns, which shouldn't be the case as I am looping through one column at the time. I am probably missing a basic concept but looking through other SO posts didn't find anything I could use. My goal is to fix the code to make the right calculation but I also would like to understand why this code above is not working. Thanks so much.
The problem is in using [ and not [[. So, instead of looping through each of the elements in 'Group' column, we have a list of length 1 with all the elements. So, either use coldata[, 'Group'] or coldata[['Group']] or coldata$Group for looping.
countsdataNew <- countsdata
countsdataNew[] <- lapply(coldata[['Group']],function(group_i)
countsdata[,group_i]/coldata$Norm[coldata$Group==group_i])
countsdataNew
# genotype1 genotype2 genotype3 genotype4
#1 10 50 8 8
#2 20 100 10 10
#3 30 150 12 12
#4 40 200 14 14
If the column name in 'countsdata' and 'Group' column from 'countsdata' are in the same order, we can do this easily with Map
Map(`/`, countsdata, coldata$Norm)
Or just replicate the 'Norm' and do a simple division
countsdata/coldata$Norm[col(countsdata)]
Or with sweep
sweep(countsdata, 2, coldata$Norm, "/")
I am relatively new to R from Stata. I have a data frame that has 100+ columns and thousands of rows. Each row has a start value, stop value, and 100+ columns of numerical values. The goal is to get the sum of each row from the column that corresponds to the start value to the column that corresponds to the stop value. This is direct enough to do in a loop, that looks like this (data.frame is df, start is the start column, stop is the stop column):
for(i in 1:nrow(df)) {
df$out[i] <- rowSums(df[i,df$start[i]:df$stop[i]])
}
This works great, but it is taking 15 minutes or so. Does anyone have any suggestions on a faster way to do this?
You can do this using some algebra (if you have a sufficient amount of memory):
DF <- data.frame(start=3:7, end=4:8)
DF <- cbind(DF, matrix(1:50, nrow=5, ncol=10))
# start end 1 2 3 4 5 6 7 8 9 10
#1 3 4 1 6 11 16 21 26 31 36 41 46
#2 4 5 2 7 12 17 22 27 32 37 42 47
#3 5 6 3 8 13 18 23 28 33 38 43 48
#4 6 7 4 9 14 19 24 29 34 39 44 49
#5 7 8 5 10 15 20 25 30 35 40 45 50
take <- outer(seq_len(ncol(DF)-2)+2, DF$start-1, ">") &
outer(seq_len(ncol(DF)-2)+2, DF$end+1, "<")
diag(as.matrix(DF[,-(1:2)]) %*% take)
#[1] 7 19 31 43 55
If you are dealing with values of all the same types, you typically want to do things in matrices. Here is a solution in matrix form:
rows <- 10^3
cols <- 10^2
start <- sample(1:cols, rows, replace=T)
end <- pmin(cols, start + sample(1:(cols/2), rows, replace=T))
# first 2 cols of matrix are start and end, the rest are
# random data
mx <- matrix(c(start, end, runif(rows * cols)), nrow=rows)
# use `apply` to apply a function to each row, here the
# function sums each row excluding the first two values
# from the value in the start column to the value in the
# end column
apply(mx, 1, function(x) sum(x[-(1:2)][x[[1]]:x[[2]]]))
# df version
df <- as.data.frame(mx)
df$out <- apply(df, 1, function(x) sum(x[-(1:2)][x[[1]]:x[[2]]]))
You can convert your data.frame to a matrix with as.matrix. You can also run the apply directly on your data.frame as shown, which should still be reasonably fast. The real problem with your code is that your are modifying a data frame nrow times, and modifying data frames is very slow. By using apply you get around that by generating your answer (the $out column), which you can then cbind back to your data frame (and that means you modify your data frame just once).