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I have a dataset with multiple variables. Each question has the actual survey answer and three other characteristics. So there are four variables for each question. I want to specify if Q135_L ==1 , leave Q135_RT as it is, otherwise code it as NA. I can do that with an ifelse statement.
df$Q135_RT <- ifelse(df$Q135_L == 1, df$Q22_RT, NA)
However, I have hundreds of variables and the names are not related. For example, in the picture we can see Q135, SG1_1 and so on. How can I specify for the whole dataset if a variable ends at _L, then for the same variable ending at _RT should remain as it is, otherwise the variable ending at _RT should be coded as NA.
I tried this but it only returns NAs
ifelse(grepl("//b_L" ==1, df), "//b_RT" , NA)
If I understand your problem correctly, you have a data frame of which the columns represent survey question variables. Each column contains two identifiers, namely: a survey question number (134, 135, etc) and a variable letter (L, R, etc). Because you provide no reproducible example, I tried to make a simplified example of your data frame:
set.seed(5)
DF <- data.frame(array(sample(1:4, 24, replace = TRUE), c(4,6)))
colnames(DF) <- c("Q134_L","Q135_L", "Q134_R", "Q135_R", "Q_L1", "Q134_S")
DF
# Q134_L Q135_L Q134_R Q135_R Q_L1 Q134_S
# 1 2 3 2 3 1 1
# 2 3 1 3 2 4 4
# 3 1 1 3 2 4 3
# 4 3 1 3 3 2 1
What you want is that if Q135_L == 1, leave Q135_RT as it is, otherwise code it as NA. Here is a function that implements this recoding logic:
recode <- function(yourdf, questnums) {
for (k in 1:length(questnums)) {
charnum <- as.character(questnums)
col_end_L_k <- yourdf[grepl("_L\\b", colnames(yourdf)) &
grepl(charnum[k], colnames(yourdf))]
col_end_R_k <- yourdf[grepl("_RT\\b", colnames(yourdf)) &
grepl(charnum[k], colnames(yourdf))]
row_is_1 <- which(col_end_L_k == 1)
col_end_R_k[-row_is_1, ] <- NA
yourdf[, colnames(col_end_R_k)] <- col_end_R_k
}
return(yourdf)
}
This function takes a data frame and a vector of question numbers, and then returns the data frame that has been recoded.
What this function does:
Selecting each question number using for.
Using grepl to identify any column that contains the selected number and contains _L at the end of the column name.
Similar with above but for _RT at the end of the column name.
Using which to identify the location of rows in the _L column that contain 1.
Keeping the values of the _RT column, which has the same question number with the corresponding _L column, in those rows, and change values on other rows to NA.
The result:
recode(DF, 134:135)
# Q134_L Q135_L Q134_RT Q135_RT Q_L1 Q134_S
# 1 2 3 NA NA 1 1
# 2 3 1 NA 2 4 4
# 3 1 1 3 2 4 3
# 4 3 1 NA 3 2 1
Note that the Q_L1 column is not affected because _L in this column is not located on the end of the column name.
As for how to define questnums, the question numbers, you just need to create a numeric vector. Examples:
Your questnums are 1 to 200. Then use 1:200 or seq(200), so recode(DF, 1:200).
Your questnums are 1, 3, 134, 135. Then, use recode(DF, c(1, 3, 134, 135)).
You can also assign the question numbers to an object first, such as n = c(25, 135, 145) and the use it : recode(DF, n)
I have long vector of patient statuses in R that are chronologically sorted, and a label of associated patient IDs. This vector is an element of a dataframe. I would like to label consecutive rows of data for which the patient status is the same. If the status changes, then reverts to its original value, that would be three separate events. This is different than most situations I have searched where duplicated or match would suffice.
An example would be along the lines of:
s <- c(0,0,0,1,1,1,0,0,2,1,1,0,0)
id <- c(1,1,1,1,1,1,1,2,2,2,2,2,2)
and the desired output would be
flag <- c(1,1,1,2,2,2,3,1,2,3,4,4)
or
flag <- c(1,1,1,2,2,2,3,4,5,6,7,7)
One inelegant approach would be to generate the sequence:
unlist(tapply(s, id, function(x) cumsum(c(T, x[-1] != rev(rev(x)[-1])))))
Is there a better way?
I think you could use rleid from data.table for this:
library(data.table)
rleid(s,id)
Output:
1 1 1 2 2 2 3 4 5 6 6 7 7
Or for the first sequence:
data.table(s,id)[,rleid(s),id]$V1
Output:
1 1 1 2 2 2 3 1 2 3 3 4 4
Run Length Encoding - rle()
tapply(s, id, function(x) {
v<-rle(x)$length
rep(1:length(v), v)
})
I would like to use the vector:
time.int<-c(1,2,3,4,5) #vector to be use as a "guide"
and the database:
time<-c(1,1,1,1,5,5,5)
value<-c("s","s","s","t","d","d","d")
dat1<- as.data.frame(cbind(time,value))
to create the following vector, which I can then add to the first vector "time.int" into a second database.
freq<-c(4,0,0,0,3) #wished result
This vector is the sum of the events that belong to each time interval, there are four 1 in "time" so the first value gets a four and so on.
Potentially I would like to generalize it so that I can decide the interval, for example saying sum in a new vector the events in "times" each 3 numbers of time.int.
EDIT for generalization
time.int<-c(1,2,3,4,5,6)
time<-c(1,1,1,2,5,5,5,6)
value<-c("s","s","s","t", "t","d","d","d")
dat1<- data.frame(time,value)
let's say I want it every 2 seconds (every 2 time.int)
freq<-c(4,0,4) #wished result
or every 3
freq<-c(4,4) #wished result
I know how to do that in excel, with a pivot table.
sorry if a duplicate I could not find a fitting question on this website, I do not even know how to ask this and where to start.
The following will produce vector freq.
freq <- sapply(time.int, function(x) sum(x == time))
freq
[1] 4 0 0 0 3
BTW, don't use the construct as.data.frame(cbind(.)). Use instead
dat1 <- data.frame(time,value))
In order to generalize the code above to segments of time.int of any length, I believe the following function will do it. Note that since you've changed the data the output for n == 1 is not the same as above.
fun <- function(x, y, n){
inx <- lapply(seq_len(length(x) %/% n), function(m) seq_len(n) + n*(m - 1))
sapply(inx, function(i) sum(y %in% x[i]))
}
freq1 <- fun(time.int, time, 1)
freq1
[1] 3 1 0 0 3 1
freq2 <- fun(time.int, time, 2)
freq2
[1] 4 0 4
freq3 <- fun(time.int, time, 3)
freq3
[1] 4 4
We can use the table function to count the event number and use merge to create a data frame summarizing the information. event_dat is the final output.
# Create example data
time.int <- c(1,2,3,4,5)
time <- c(1,1,1,1,5,5,5)
# Count the event using table and convert to a data frame
event <- as.data.frame(table(time))
# Convert the time.int to a data frame
time_dat <- data.frame(time = time.int)
# Merge the data
event_dat <- merge(time_dat, event, by = "time", all = TRUE)
# Replace NA with 0
event_dat[is.na(event_dat)] <- 0
# See the result
event_dat
time Freq
1 1 4
2 2 0
3 3 0
4 4 0
5 5 3
I have Valence Category for word stimuli in my psychology experiment.
1 = Negative, 2 = Neutral, 3 = Positive
I need to sort the thousands of stimuli with a pseudo-randomised condition.
Val_Category cannot have more than 2 of the same valence stimuli in a row i.e. no more than 2x negative stimuli in a row.
for example - 2, 2, 2 = not acceptable
2, 2, 1 = ok
I can't sequence the data i.e. decide the whole experiment will be 1,3,2,3,1,3,2,3,2,2,1 because I'm not allowed to have a pattern.
I tried various packages like dylpr, sample, order, sort and nothing so far solves the problem.
I think there's a thousand ways to do this, none of which are probably very pretty. I wrote a small function that takes care of the ordering. It's a bit hacky, but it appeared to work for what I tried.
To explain what I did, the function works as follows:
Take the vector of valences and samples from it.
If sequences are found that are larger than the desired length, then, (for each such sequence), take the last value of that sequence at places it "somewhere else".
Check if the problem is solved. If so, return the reordered vector. If not, then go back to 2.
# some vector of valences
val <- rep(1:3,each=50)
pseudoRandomize <- function(x, n){
# take an initial sample
out <- sample(val)
# check if the sample is "bad" (containing sequences longer than n)
bad.seq <- any(rle(out)$lengths > n)
# length of the whole sample
l0 <- length(out)
while(bad.seq){
# get lengths of all subsequences
l1 <- rle(out)$lengths
# find the bad ones
ind <- l1 > n
# take the last value of each bad sequence, and...
for(i in cumsum(l1)[ind]){
# take it out of the original sample
tmp <- out[-i]
# pick new position at random
pos <- sample(2:(l0-2),1)
# put the value back into the sample at the new position
out <- c(tmp[1:(pos-1)],out[i],tmp[pos:(l0-1)])
}
# check if bad sequences (still) exist
# if TRUE, then 'while' continues; if FALSE, then it doesn't
bad.seq <- any(rle(out)$lengths > n)
}
# return the reordered sequence
out
}
Example:
The function may be used on a vector with or without names. If the vector was named, then these names will still be present on the pseudo-randomized vector.
# simple unnamed vector
val <- rep(1:3,each=5)
pseudoRandomize(val, 2)
# gives:
# [1] 1 3 2 1 2 3 3 2 1 2 1 3 3 1 2
# when names assigned to the vector
names(val) <- 1:length(val)
pseudoRandomize(val, 2)
# gives (first row shows the names):
# 1 13 9 7 3 11 15 8 10 5 12 14 6 4 2
# 1 3 2 2 1 3 3 2 2 1 3 3 2 1 1
This property can be used for randomizing a whole data frame. To achieve that, the "valence" vector is taken out of the data frame, and names are assigned to it either by row index (1:nrow(dat)) or by row names (rownames(dat)).
# reorder a data.frame using a named vector
dat <- data.frame(val=rep(1:3,each=5), stim=rep(letters[1:5],3))
val <- dat$val
names(val) <- 1:nrow(dat)
new.val <- pseudoRandomize(val, 2)
new.dat <- dat[as.integer(names(new.val)),]
# gives:
# val stim
# 5 1 e
# 2 1 b
# 9 2 d
# 6 2 a
# 3 1 c
# 15 3 e
# ...
I believe this loop will set the Valence Category's appropriately. I've called the valence categories treat.
#Generate example data
s1 = data.frame(id=c(1:10),treat=NA)
#Setting the first two rows
s1[1,"treat"] <- sample(1:3,1)
s1[2,"treat"] <- sample(1:3,1)
#Looping through the remainder of the rows
for (i in 3:length(s1$id))
{
s1[i,"treat"] <- sample(1:3,1)
#Check if the treat value is equal to the previous two values.
if (s1[i,"treat"]==s1[i-1,"treat"] & s1[i-1,"treat"]==s1[i-2,"treat"])
#If so draw one of the values not equal to that value
{
a = 1:3
remove <- s1[i,"treat"]
a=a[!a==remove]
s1[i,"treat"] <- sample(a,1)
}
}
This solution is not particularly elegant. There may be a much faster way to accomplish this by sorting several columns or something.
I'm pretty confused on how to go about this. Say I have two columns in a dataframe. One column a numerical series in order (x), the other specifying some value from the first, or -1 (y). These are results from a matching experiment, where the goal is to see if multiple photos are taken of the same individual. In the example below, there 10 photos, but 6 are unique individuals. In the y column, the corresponding x is reported if there is a match. y is -1 for no match (might as well be NAs). If there is more than 2 photos per individual, the match # will be the most recent record (photo 1, 5 and 7 are the same individual below). The group is the time period the photo was take (no matches within a group!). Hopefully I've got this example right:
x <- c(1,2,3,4,5,6,7,8,9,10)
y <- c(-1,-1,-1,-1,1,-1,1,-1,2,4)
group <- c(1,1,1,2,2,2,3,3,3,3)
DF <- data.frame(x,y,group)
I would like to create a new variable to name the unique individuals, and have a final dataset with a single row per individual (i.e. only have 6 rows instead of 10), that also includes the group information. I.e. if an individual is in all three groups, there could be a value of "111" or if just in the first and last group it would be "101". Any tips?
Thanks for asking about the resulting dataset. I realized my group explanation was bad based on the actual numbers I gave, so I changed the results slightly. Bonus would also be nice to have, but not critical.
name <- c(1,2,3,4,6,8)
group_history <- as.character(c('111','101','100','011','010','001'))
bonus <- as.character(c('1,5,7','2,9','3','4,10','6','8'))
results_I_want <- data.frame(name,group_history,bonus)
My word, more mistakes fixed above...
Using the (updated) example you gave
x <- c(1,2,3,4,5,6,7,8,9,10)
y <- c(-1,-1,-1,-1,1,-1,1,-1,3,4)
group <- c(1,1,1,2,2,2,3,3,3,3)
DF <- data.frame(x,y,group)
Use the x and y to create a mapping from higher numbers to lower numbers that are the same person. Note that names is a string, despite it be a string of digits.
bottom.df <- DF[DF$y==-1,]
mapdown.df <- DF[DF$y!=-1,]
mapdown <- c(mapdown.df$y, bottom.df$x)
names(mapdown) <- c(mapdown.df$x, bottom.df$x)
We don't know how many times it might take to get everything down to the lowest number, so have to use a while loop.
oldx <- DF$x
newx <- mapdown[as.character(oldx)]
while(any(oldx != newx)) {
oldx = newx
newx = mapdown[as.character(oldx)]
}
The result is the group it belongs to, names by the lowest number of that set.
DF$id <- unname(newx)
Getting the group membership is harder. Using reshape2 to convert this into wide format (one column per group) where the column is "1" if there was something in that one and "0" if not.
library("reshape2")
wide <- dcast(DF, id~group, value.var="id",
fun.aggregate=function(x){if(length(x)>0){"1"}else{"0"}})
Finally, paste these "0"/"1" memberships together to get the grouping variable you described.
wide$grouping = apply(wide[,-1], 1, paste, collapse="")
The result:
> wide
id 1 2 3 grouping
1 1 1 1 1 111
2 2 1 0 0 100
3 3 1 0 1 101
4 4 0 1 1 011
5 6 0 1 0 010
6 8 0 0 1 001
No "bonus" yet.
EDIT:
To get the bonus information, it helps to redo the mapping to keep everything. If you have a lot of cases, this could be slow.
Replace the oldx/newx part with:
iterx <- matrix(DF$x, ncol=1)
iterx <- cbind(iterx, mapdown[as.character(iterx[,1])])
while(any(iterx[,ncol(iterx)]!=iterx[,ncol(iterx)-1])) {
iterx <- cbind(iterx, mapdown[as.character(iterx[,ncol(iterx)])])
}
DF$id <- iterx[,ncol(iterx)]
To generate the bonus data, then you can use
bonus <- tapply(iterx[,1], iterx[,ncol(iterx)], paste, collapse=",")
wide$bonus <- bonus[as.character(wide$id)]
Which gives:
> wide
id 1 2 3 grouping bonus
1 1 1 1 1 111 1,5,7
2 2 1 0 0 100 2
3 3 1 0 1 101 3,9
4 4 0 1 1 011 4,10
5 6 0 1 0 010 6
6 8 0 0 1 001 8
Note this isn't same as your example output, but I don't think your example output is right (how can you have a grouping_history of "000"?)
EDIT:
Now it agrees.
Another solution for bonus variable
f_bonus <- function(data=df){
data_a <- subset(data,y== -1,select=x)
data_a$pos <- seq(nrow(data_a))
data_b <- subset(df,y!= -1,select=c(x,y))
data_b$pos <- match(data_b$y, data_a$x)
data_t <- rbind(data_a,data_b[-2])
data_t <- with(data_t,tapply(x,pos,paste,sep="",collapse=","))
return(data_t)
}