Just to give some background first:
I currently have 2 data frames (giraffe, leaf) and both of them share the column 'key', where the elements in the leaf data frame are a subset of giraffe. What I needed to do is compare the two data frames and when there are matching elements in both data frames in the 'key' column, the string 'leaf' will be input into another column (project) in the giraffe data frame inside the same row as the matching 'key' element. I've taken the following approach however it seems I have made a small error somewhere and after searching online, I still don't know what it is:
Truth_vector <- is.element((giraffe[,1]),(leaf[,1])) #returns a vector with 3000 elements, most are FALSE except for where the element inside 'key' is present in both data frames
i=1
for (i in 1:length(giraffe[,1])) {
if Truth_vector[i] == TRUE {
giraffe[i,5] <- 'leaf'
}
i = i+1
}
Error: unexpected '}' in "}"
Edit:
I tried implementing the solution as a function however nothing ends up happening, no error messages get returned either. What I've done is:
Project_assign <- function(prjct) {
Truth_vector <- is.element((giraffe[,1]),(prjct[,1]))
giraffe[which(Truth_vector),5] <- 'prjct'
}
Project_assign(leaf)
Edit: This was because everything was getting assigned in the function sub environment, not the global environment. Using assign('giraffe',giraffe,envir=.GlobalEnv) solves this however you should try and avoid the assign function and Instead I used a for loop going over a list of all the dataframes
You have a couple issues. First, the if criteria needs to be in parentheses, and secondly you don't need to increment i yourself. This should suffice:
for (i in 1:length(giraffe[,1])) {
if (Truth_vector[i] == TRUE) {
giraffe[i,5] <- 'leaf'
}
}
Of course, this would do it too:
giraffe[which(Truth_vector),5] <- 'leaf'
(assuming Truth_vector is not longer than the number of rows in giraffe)
Related
I am trying to create a data frame of various error messages based on Data to be cross checked between two dataframes and storing the message in a vector in an iterative manner . I am using the following snippet for this purpose :
> for(j in 1:nrow(MySQL_Data)){ date_mysql=
> paste("MySQL_Data[",j,",1]") date_red= paste("RED_Data[",j,",1]")
> body= c() if(!date_mysql == date_red) {
> body<- append(body,paste("'There is data missing for date",date_mysql,"in",table2)) }else {
> NULL }}
My table2 variable prints as MYSQL_Data[2,1] instead of the actual value of the variable which is a date
Following is the Output :
"'There is data missing for date MySQL_Data[ 2 ,1] in Dream11_UserRegistration"
Can someone help me with the error that I am committing here..
Thanks in Advance !
Your use of paste in the definitions of data_mysql and data_red makes no sense. I’m assuming that what you actually want is this:
data_mysql = MySQL_Data[j, 1]
data_red = RED_Data[j, i]
Furthermore, you’re resetting body in every loop iteration so it will only ever hold a single element.
I'm using assign() to assign some new data frames from some other data frame. I then want to name some of the columns in the new data frame. When I use assign() to create the new data frames it works fine. But when I use the assign() inside of colnames() is gives the error 'Error "could not find function "assign<-".'
Here's my snippet of code(abbreviated of course):
for(i in 1:value) {
assign(Name[i], Old.Data.Frame[Old.Data.Frame$1 == Index[i]]) #I'm going to call this line of code 'New Data Frame' for brevity
for(j in 1:ncol(New Data Frame)) {
colnames(New Data Frame)[j] = as.character(Old.Data.Frame[3,j])
I do all this assign() stuff because the names of the Old Data Frame constantly change and I can create any concrete variables in my code, only the dimentions of the frame stay the same.
The only error in this code is that R cannot "find function assign<- in colnames(...". I'm flustered because assign() had just worked in the line before, any help is appreciated, thanks!
You have a list of variable names in Name, which you assign a value (your code block).
for(i in 1:value) { assign(Name[i], Old.Data.Frame[Old.Data.Frame$1 == Index[i]]) }
Could you then try (note I'm separating this code block for debugging purposes):
for(i in 1:value) { colnames(get(Names[i])) <- as.character(Old.Data.Frame[3,] }
get will retrieve the data (data.frame) assigned to the variable name Names[i] (character)
I am trying to delete all values in a list that have the tag ".dsw". My list is a list of files using the function list.files. This is my code:
for (file in GRef) {
if (strsplit(file, "[.]")[[1]][3] == "dsw") {
#GRef=GRef[-file]
for(n in 1:length(GRef)){
if (GRef[n] == file){
GRef=GRef[-n]
}
}
}
}
Where GRef is the list of file names. I get the error listed above, but I dont understand why. I have looked at this post: Error .. missing value where TRUE/FALSE needed, but I dont think it is the same thing.
You shouldn't attempt to to modify a vector while you are looping over it. The problem is your are removing items you are then trying to extract later which is causing the missing values. It's better to identify all the items you want remove first, then remove them. For example
GRef <- c("a.file.dsw", "b.file.txt", "c.file.gif", "d.file.dsw")
exts <- sapply(strsplit(GRef, "[.]"), `[`, 3)
GRef <- GRef[exts!="dsw"]
We were trying to write the results from a for loop. We tried to use write.table, as.data.frame and other solutions, but with no success. We expect to have a data frame.
Currently we have only the loop, that shows year and values from a matrix which are bigger than 50. Looks like that:
for (i in 1:nrow(dobowe1)) {
if(dobowe1[i,4]>50) {
cat(dobowe1[i,"rok"],dobowe1[i,4], "\n")
}
}
Note: We don't do programming a lot, so it's hard to use other solutions from the questions that already beed asked.
Try to save each element to the vector, like here:
tabela <- numeric(nrow(dobowe1))
for (i in 1:nrow(dobowe1)) {
if(dobowe1[i,4]>50) {
tabela[i] <- paste(dobowe1[i,"rok"],dobowe1[i,4])
}
}
as.data.frame(tabela)
If you just want to visually inspect a subset of your matrix, you can just print out a filtered subset:
# create the filter:
> f <- dobowe1[,4] > 50
# use the filter to subset (index) your data.frame:
> dobowe1[f,c("rok", whatever-4th-var-is-called)]
This will automatically print it out. Or you can write it to a file with ?write.table
I'd like to get the unique elements from a column. That seems straight forward. Both of these work, but I'm not getting the object type I'd like:
userlist <- as.list(somebigdf$username)
userlist <- unique(userlist)
or
userlist <- unique(somebigdf$username)
When I iterate through, I'm not getting the names:
for(i in 1:length(userlist)){
cat(names(userlist[i]), '\n')
}
Returns blank spaces.
for(i in userlist){
cat(i, '\n')
}
Returns integers.
The above function is just an example. I'll be using that but also matching the returned name in an if-else function.
The object types seem to be integers or an extended data.frame with lots of values for each name - which isn't what I want. I would really just like a list of strings something along the lines of userlist = c( the results from unique).
Edit -
This code will iterate correctly through the names:
for(name in unique(somebigdf$username)){
cat(name, '\n')
}
I'm accepting my own answer. Namely, a working solution - this code will iterate correctly through the names:
for(name in unique(somebigdf$username)){
cat(name, '\n')
}
If someone at a later date has a better answer that seems more in keeping with the question, I will be happy to accept that as the answer.