I just started working with R for my master thesis and up to now all my calculations worked out as I read a lot of questions and answers here (and it's a lot of trial and error, but thats ok).
Now i need to process a more sophisticated code and i can't find a way to do this.
Thats the situation: I have multiple sub-data-sets with a lot of entries, but they are all structured in the same way. In one of them (50000 entries) I want to change only one value every row. The new value should be the amount of the existing entry plus a few values from another sub-data-set (140000 entries) where the 'ID'-variable is the same.
As this is the third day I'm trying to solve this, I already found and tested for and apply but both are running for hours (canceled after three hours).
Here is an example of one of my attempts (with for):
for (i in 1:50000) {
Entry_ID <- Sub02[i,4]
SUM_Entries <- sum(Sub03$Source==Entry_ID)
Entries_w_ID <- subset(Sub03, grepl(Entry_ID, Sub03$Source)) # The Entry_ID/Source is a character
Value1 <- as.numeric(Entries_w_ID$VAL1)
SUM_Value1 <- sum(Value1)
Value2 <- as.numeric(Entries_w_ID$VAL2)
SUM_Value2 <- sum(Value2)
OLD_Val1 <- Sub02[i,13]
OLD_Val <- as.numeric(OLD_Val1)
NEW_Val <- SUM_Entries + SUM_Value1 + SUM_Value2 + OLD_Val
Sub02[i,13] <- NEW_Val
}
I know this might be a silly code, but thats the way I tried it as a beginner. I would be very grateful if someone could help me out with this so I can get along with my thesis.
Thank you!
Here's an example of my data-structure:
Text VAL0 Source ID VAL1 VAL2 VAL3 VAL4 VAL5 VAL6 VAL7 VAL8 VAL9
XXX 12 456335667806925_1075080942599058 10153901516433434_10153902087098434 4 1 0 0 4 9 4 6 8
ABC 8 456335667806925_1057045047735981 10153677787178434_10153677793613434 6 7 1 1 5 3 6 8 11
DEF 8 456747267806925_2357045047735981 45653677787178434_94153677793613434 5 8 2 1 5 4 1 1 9
The output I expect is an updated value 'VAL9' in every row.
From what I understood so far, you need 2 things:
sum up some values in one dataset
add them to another dataset, using an ID variable
Besides what #yoland already contributed, I would suggest to break it down in two separate tasks. Consider these two datasets:
a = data.frame(x = 1:2, id = letters[1:2], stringsAsFactors = FALSE)
a
# x id
# 1 1 a
# 2 2 b
b = data.frame(values = as.character(1:4), otherid = letters[1:2],
stringsAsFactors = FALSE)
sapply(b, class)
# values otherid
# "character" "character"
Values is character now, we need to convert it to numeric:
b$values = as.numeric(b$values)
sapply(b, class)
# values otherid
# "numeric" "character"
Then sum up the values in b (grouped by otherid):
library(dplyr)
b = group_by(b, otherid)
b = summarise(b, sum_values = sum(values))
b
# otherid sum_values
# <chr> <dbl>
# 1 a 4
# 2 b 6
Then join it with a - note that identifiers are specified in c():
ab = left_join(a, b, by = c("id" = "otherid"))
ab
# x id sum_values
# 1 1 a 4
# 2 2 b 6
We can then add the result of the sum from b to the variable x in a:
ab$total = ab$x + ab$sum_values
ab
# x id sum_values total
# 1 1 a 4 5
# 2 2 b 6 8
(Updated.)
From what I understand you want to create a new variable that uses information from two different data sets indexed by the same ID. The easiest way to do this is probably to join the data sets together (if you need to safe memory, just join the columns you need). I found dplyr's join functions very handy for these cases (explained neatly here) Once you joined the data sets into one, it should be easy to create the new columns you need. e.g.: df$new <- df$old1 + df$old2
Related
Thank you good ppl! This must be simple but I'm banging my head against it for a while. Please help. I have a large data set from which I get all kinds of information via table(). I then want to store that information which is essentially different counts, so I also want to store the rownames that were counted. For a reproducible example consider
```
a<-c("a","b","c","d","a","b") #one count, occurring twice for a and
b and once for c and d
b<-c("a","c") # a completly different property from the dataset
occurring once for a and c
x<-table(a)
y<-table(b) #so now x and y hold the information I seek
How can I merge/bind/whatever to get from x and y to this form:
x. y.
a 2. 1
b 2. 0
c 1. 1
d. 1 0
HOWEVER, I need to use the solution iteratively, in a loop that takes x and y and gets the requested form above, and then gets more tables added, each hopefully adding a column. One of my many failed attempts, just to show the logic, is:
`. member<-function (data=dfm,groupvar='group',analysis=kc15 {
res<-matrix(NA,ncol=length(analysis$size)+1)
res[,1]<-table(docvars(data,groupvar))
for (i in 1:length(analysis$size)) {
r<-table(docvars(data,groupvar)[analysis$cluster==i])
res<-cbind(res,r)
}
res
}`
So, to sum, the reproducible example above means to replicate the first column in res and an r, and I'm seeking (I think) a correct solution instead of the cbind, which would allow adding columns of different length but similar names, as in the example above.
Please help its embarrassing how much time I'm wasting on this
In base R, you can use table, stack and full join the two counts.
out <- merge(stack(table(a)), stack(table(b)), by = 'ind', all = TRUE)
out
# ind values.x values.y
#1 a 2 1
#2 b 2 NA
#3 c 1 1
#4 d 1 NA
If you want to replace NA with 0, you can do :
out[is.na(out)] <- 0
One purrr and tidyr solution could be:
map_dfr(lst, ~ stack(table(.)), .id = "ID") %>%
pivot_wider(names_from = "ID", values_from = "values", values_fill = list(values = 0))
ind a b
<chr> <int> <int>
1 a 2 1
2 b 2 0
3 c 1 1
4 d 1 0
lst being:
lst <- list(a = a,
b = b)
I have a dataset with tens of columns that looks something like this:
df <- data.frame(id= c(1,1,1,2,2,2,3,3,3), time=c(1,2,3,1,2,3,1,2,3),y1 = rnorm(9), y2= rnorm(9), x = rnorm(9), xb = rnorm(9))
df
# id time y1 y2 x xb
# 1 1 1 -1.1184009 -1.07430118 0.61398523 -0.68343624
# 2 1 2 0.4347047 -0.53454071 -0.30716538 -1.02328242
# 3 1 3 0.2318315 -0.05854228 0.05169733 -0.22130149
# 4 2 1 1.2640080 2.07899296 -0.95918953 -0.35961156
# 5 2 2 -0.4374764 -0.25284854 -0.46251901 0.08630344
# 6 2 3 0.5042690 0.13322671 1.00881113 0.43807458
# 7 3 1 0.3672216 1.92995242 0.48708183 0.58206127
# 8 3 2 -1.5431709 0.53362731 1.17361087 -1.00932195
# 9 3 3 -1.4577268 0.23413541 -0.32399489 -0.91040641
I would like to modify my data frame using the following logic
df<-setDT(df)[,y1:=ifelse(y1>x,x,y1))]
df<-setDT(df)[,y2:=ifelse(y2>xb,xb,y2))]
However, since I have many variables I would like to do this in a single line expression. In other words, I would like to pass this function for multiple columns at once i.e. y1 with x, y2 with xb and so on...
I have tried the following but it does not seem to work
mod<-c("y1","y2")
max<-c("x","xb")
df2<-setDT(ppta)[,(mod):=ifelse(.(mod)>.(max),.(max),.(mod))]
does anyone knows what I am doing wrong? and how I modify multiple columns with their respective partner column at once?
Consider using pmin instead of your ifelse. You can try:
mod<-c("y1","y2")
max<-c("x","xb")
setDT(df)
df[,c(mod):=Map(pmin,mget(mod),mget(max))]
Explanation:
pmin takes two (or more) vectors and gives the minimum value for each element (equivalent of your ifelse(y1>x,x,y1));
mget returns a list of objects from their names. For instance mget("a","b") returns a list with the a and b objects (if they exist). This is used to retrieve the column from their name in the environment of the data table;
Map applies a function with more arguments element by element. Map(f,a,b) is equivalent to list(f(a[[1]],b[[1]]),f(a[[2]],b[[2]]),...).
I have a data frame like this:
x=data.frame(type = c('a','b','c','a','b','a','b','c'),
value=c(5,2,3,2,10,6,7,8))
every item has attributes a, b, c while some records may be missing records, i.e. only have a and b
The desired output is
y=data.frame(item=c(1,2,3), a=c(5,2,6), b=c(2,10,7), c=c(3,NA,8))
How can I transform x to y? Thanks
We can use dcast
library(data.table)
out <- dcast(setDT(x), rowid(type) ~ type, value.var = 'value')
setnames(out, 'type', 'item')
out
# item a b c
#1: 1 5 2 3
#2: 2 2 10 8
#3: 3 6 7 NA
Create a grouping vector g assuming each occurrence of a starts a new group, use tapply to create a table tab and coerce that to a data frame. No packages are used.
g <- cumsum(x$type == "a")
tab <- with(x, tapply(value, list(g, type), c))
as.data.frame(tab)
giving:
a b c
1 5 2 3
2 2 10 NA
3 6 7 8
An alternate definition of the grouping vector which is slightly more complex but would be needed if some groups have a missing is the following. It assumes that x lists the type values in order of their levels within group so that if a level is less than the prior level it must be the start of a new group.
g <- cumsum(c(-1, diff(as.numeric(x$type))) < 0)
Note that ultimately there must be some restriction on missingness; otherwise, the problem is ambiguous. For example if one group can have b and c missing and then next group can have a missing then whether b and c in the second group actually form a second group or are part of the first group is not determinable.
I have Valence Category for word stimuli in my psychology experiment.
1 = Negative, 2 = Neutral, 3 = Positive
I need to sort the thousands of stimuli with a pseudo-randomised condition.
Val_Category cannot have more than 2 of the same valence stimuli in a row i.e. no more than 2x negative stimuli in a row.
for example - 2, 2, 2 = not acceptable
2, 2, 1 = ok
I can't sequence the data i.e. decide the whole experiment will be 1,3,2,3,1,3,2,3,2,2,1 because I'm not allowed to have a pattern.
I tried various packages like dylpr, sample, order, sort and nothing so far solves the problem.
I think there's a thousand ways to do this, none of which are probably very pretty. I wrote a small function that takes care of the ordering. It's a bit hacky, but it appeared to work for what I tried.
To explain what I did, the function works as follows:
Take the vector of valences and samples from it.
If sequences are found that are larger than the desired length, then, (for each such sequence), take the last value of that sequence at places it "somewhere else".
Check if the problem is solved. If so, return the reordered vector. If not, then go back to 2.
# some vector of valences
val <- rep(1:3,each=50)
pseudoRandomize <- function(x, n){
# take an initial sample
out <- sample(val)
# check if the sample is "bad" (containing sequences longer than n)
bad.seq <- any(rle(out)$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 am trying to build a for loop which will step through each site, for that site calculate frequencies of a response, and put those results in a new data frame. Then after the loop I want to be able to combine all of the site data frames so it will look something like:
Site Genus Freq
1 A 50
1 B 30
1 C 20
2 A 70
2 B 10
2 C 20
But to do this I need my names (of vectors, dataframes) to change each time through the loop. I think I can do this using the SiteNum variable, but how do I insert it into new variable names? The way I tried (below) treats it like part of the string, doesn't insert the value for the name.
I feel like what I want to use is a placeholder %, but I don't know how to do that with variable names.
> SiteNum <- 1
> for (Site in CoralSites){
> Csub_SiteNum <- subset(dfrmC, Site==CoralSites[SiteNum])
> CGrfreq_SiteNum <- numeric(length(CoralGenera))
> for (Genus in CoralGenera){
> CGrfreq_SiteNum[GenusNum] <- mean(dfrmC$Genus == CoralGenera[GenusNum])*100
> GenusNum <- GenusNum + 1
> }
> names(CGrfreq_SiteNum) <- c(CoralGenera)
> Site_SiteNum <- c(Site)
> CG_SiteNum <- data.frame(CoralGenera,CGrfreq_SiteNum,Site_SiteNum)
> SiteNum <- SiteNum + 1
> }
Your question as stated asks how you can create a bunch of variables, e.g. CGrfreq_1, CGrfreq_2, ..., where the name of the variable indicates the site number that it corresponds to (1, 2, ...). While you can do such a thing with functions like assign, it is not good practice for a few reasons:
It makes your code to generate the variables more complicated because it will be littered with calls to assign and get and paste0.
It makes your data more difficult to manipulate afterwards -- you'll need to (either manually or programmatically) identify all the variables of a certain type, grab their values with get or mget, and then do something with them.
Instead, you'll find it easier to work with other R functions that will perform the aggregation for you. In this case you're looking to generate for each Site/Genus pairing the percentage of data points at the site with the particular genus value. This can be done in a few lines of code with the aggregate function:
# Sample data:
(dat <- data.frame(Site=c(rep(1, 5), rep(2, 5)), Genus=c(rep("A", 3), rep("B", 6), "A")))
# Site Genus
# 1 1 A
# 2 1 A
# 3 1 A
# 4 1 B
# 5 1 B
# 6 2 B
# 7 2 B
# 8 2 B
# 9 2 B
# 10 2 A
# Calculate frequencies
dat$Freq <- 1
res <- aggregate(Freq~Genus+Site, data=dat, sum)
res$Freq <- 100 * res$Freq / table(dat$Site)[as.character(res$Site)]
res
# Genus Site Freq
# 1 A 1 60
# 2 B 1 40
# 3 A 2 20
# 4 B 2 80