R saving results from a nested for-loop - r

I am trying to write the following loop over an empirical data set where
each ID replicate has a different number of observations for each sample period.
Any suggestions would be greatly appreciated!
a <- unique(bma$ID)
t <- unique(bma$Sample.period)
# empty list to hold the data
dens.data <- vector(mode='list', length = length(a) * length(t))
tank1 <- double(length(a))
index = 0
for (i in 1:length(a)){
for (j in 1:length(t)){
index = index + 1
tank1[index] = a[index] ### building an ID column
temp.tank <- subset(bma, bma$ID == a[i])
time.tank <- subset(temp.tank, temp.tank$Sample.period == t[j])
temp1 <- unique(temp.tank$Sample.period)
temp.tank <- data.frame(temp.tank, temp1)
dens.1 <- density(time.tank$Biomass_.adults_mgC.mm.3, na.rm = T)
# extract the y-values from the pdf function - these need to be separated by each Replicate and Sample Period
dens.data[[index]] <- dens.1$y
}
}
#### extract the data and place into a dataframe
dens.new<- data.frame(dens.data)
dens.new
colnames(dens.new) <- c("Treatment","Sample Period","pdf/density for biomass")
all<- list(dens.new)
all
### create new spreadsheet with all the data from the loop
dens.new.data<- write.csv(dens.new, "New.density.csv") ## export file to excel spreadsheet
Calling dens.new<- data.frame(dens.data) Yield the following error message:
Error in data.frame(c(...) :
arguments imply differing number of rows: 512, 0
The loop seems to work for dens.data[[1]] but returns NULL for
dens.data[[>1]]

As there isn't a minimal example, it is difficult for me to guess what the original data.frame looks like. However, as for the error message, it is clear that your for-loop fails to assign values to the list dens.data for indices greater than 1.
My guess is that the index didn't update by index = index + 1. Maybe you could try changing the equal sign = to the standard R assignment operator <- and see whether the whole list is updated.
I heard that using equal sign for assignment may cause some problems in an older version of R, but I'm not sure whether you are facing the same problem. Anyway, using <- to assign a value is always safer and recommended.

Related

R - Looping with while always results in missing value where TRUE/FALSE is expected

EDIT: I implemented offered solutions so far, and the code looks way cleaner now. This was the key to finally finding my error. It was a logical condition that I didn't check within the while loop. It could happen that the iterator would exceed the number of elements in the vector and thus pass a "NA" to the while condition! Thx
I also changed the solution to use vector assignments to store the results and then recombine after the for loop, as vector indexing seems to be way faster than data.table indexing and value assignment within the loop.
Pls let me apologize first for any errors and lack of information for troubleshooting my problem as this is my first post so far. I have already read that this can happen accidentally whenever ther is an error in a computation and the value of a condition results in an error, such as
if (TRUE & sqrt(-1))
It's been days and I am still receiving this error. It really gives me a headache, as the inherent logic behind such code is actually pretty straigth forward and I still can't properly formalize it. It goes like following: Compare for each unique bond ID contained in a vector of size N (loop through with i), the static value of its corresponding maturity to 7 periods' end date for distinct set of rules (loop through with k) to determine which periods with unique rules the respective issue falls into, and then determine by looping through all the periods' size thresholds (loop through by l) to find if a particular issue has violted these minimium size requirements. If a violation is determined, I can assign the date of the violation. If (l == k), I can reckon that for all periods that the issue's maturity falls into, have also successfully looped through the corresponding size requirements checks and as such hasn't violated any rules. I then assign the result of the conditional checks as corresponding binary values in a new data.table column as well as the violation date. So far, I really cant determine what is casusing this error.
My data looks like following. I have a pretty large data.table containing bond issue identifiers and various other column variables that describe those issues. It was imported as initially with the read_dta() function and then transformed to a data.table with setDT().
I extract 3 columns out of this data.table, using
issue_IDs.vec <- as.numeric(issues.dt[[2]])
maturity.vec <- as.Date(issues.dt[[8]], "%Y-%m-%d")
offerings_atm.vec <- as.numeric(issues.dt[[33]])
Next, I transform eligibility criteria of an index as following.
# (1) Creating size requirement end periods (valid thru) ----
size_req_per_1 <- as.Date("1992-01-01", "%Y-%m-%d")
size_req_per_2 <- as.Date("1994-01-01", "%Y-%m-%d")
size_req_per_3 <- as.Date("1999-07-01", "%Y-%m-%d")
size_req_per_4 <- as.Date("2003-10-01", "%Y-%m-%d")
size_req_per_5 <- as.Date("2004-07-01", "%Y-%m-%d")
size_req_per_6 <- as.Date("2017-02-01", "%Y-%m-%d")
size_req_per_7 <- as.Date("2021-02-01", "%Y-%m-%d")
size_req_val_per.vec <- c(size_req_per_1, size_req_per_2, size_req_per_3, size_req_per_4,
size_req_per_5, size_req_per_6, size_req_per_7)
# (2) Create a size requirement threshold per rules' validity period ----
size_req_thresh_1 <- 25000
size_req_thresh_2 <- 50000
size_req_thresh_3 <- 100000
size_req_thresh_4 <- 150000
size_req_thresh_5 <- 200000
size_req_thresh_6 <- 250000
size_req_thresh_7 <- 300000
size_req_thresh.vec <- c(size_req_thresh_1, size_req_thresh_2, size_req_thresh_3,
size_req_thresh_4, size_req_thresh_5, size_req_thresh_6,
size_req_thresh_7)
Next, I do write a loop to perform conditional checks to find for each issue ID stored in the issues_ID.vec if they violate the index eligibility criterium of the minimim issance size during their maturity. I do this by passing the value of iterator variable i as a position value to the issues_ID.vec.
# (3) Looping through a set of conditional check to find out if and if so when a particular issue violated the size requirement ---
# Iterator variables ----
# Length of issues.dt
j <- issues.dt[, .N]
# Main iterator looping through all entries of isssues.dt extracted as vector
i <- 1
# Looping through vector elements of issue rules (vec. 1: validity periods)
k <- 1
# Looping through vector elements of issue rules (vec. 2: size thresholds)
l <- 1
# Loop
for (i in 1:j) {
id <- issue_IDs.vec[i]
maturity <- maturity.vec[i]
offering_atm <- issue_IDs.vec[i]
k <- 1
maturity_comp <- size_req_val_per.vec[k]
while (maturity >= maturity_comp) {
if (k < 7) {
k <- k + 1
maturity_comp <- size_req_val_per.vec[k]
} else {
break
}
}
l <- 1
offering_size_comp <- size_req_thresh.vec[l]
for (l in 1:k) {
if (offering_atm >= offering_size_comp) {
offering_size_comp <- size_req_thresh.vec[l]
next
} else {}
}
if (l == k) {
issues.dt[ISSUE_ID == id,
`:=`(SIZE_REQ_VIOLATION = 0,
SIZE_REQ_VIOLATION_DATE = NA)]
} else {
issues.dt[ISSUE_ID == id,
`:=`(SIZE_REQ_VIOLATION = 1,
SIZE_REQ_VIOLATION_DATE = size_req_val_per.vec[l])]
}
i <- i + 1
}
Whenever I try running the code in a simplified version, such as
k <- 1
for (1 in 1:7) {
print(maturity >= maturity_comp)
k <- k + 1
maturity_comp <- format(as.Date(size_req_val_per.vec[k]), "%Y-%m-%d")
}
the code runs smooth and always results in the printed evaluations TRUE or FALSE, depending which ID I initially to create the corresponding static maturity of the particular bond issue. As this stage, I already exhasuted my troubleshooting skills.
I'd appreciate any input from you guys, and if you need any additional information, explanations etc. just let me know.
I think the answer lies in Gregor's comment. The way you are formatting your dates converts them to character variables. Here's a quick example:
Exmpl<-as.Date("08-25-2020", "%m-%d-%Y")
class(Exmpl)
[1] "Date"
##Not your preferred format, but it is a Date variable##
Exmpl
"2020-08-25"
##Formatting changes it to a character
Exmpl2<-format(as.Date(Exmpl), "%m-%d-%Y")
class(Exmpl2)
[1] "character"
When you call them in the while() function, R is trying make a comparison to decided if the condition (i.e., maturity is greater than or equal to maturity comp) is TRUE or FALSE (logical variables). Because you have character variables, R cannot make this comparison.
I think your code will work if you don't format the dates, but simply read them in and leave them in the YYYY-mm-dd format.

Using for loop in a function, only returns last value

I am writing a function which takes a directory of data, and reads them in, and (if it reaches the threshold of complete cases), calculates the correlation between two variables in the data ("sulfate" and "nitrate"). I want this to run in a for loop to create a numeric vector of the correlation values (one value for each file in the directory).
However, when I run the code, it only returns the last value.
I am quite new to R (so may be making simple mistakes, and have the newest version of R installed). Below is the code:
corr <- function(directory, threshold = 0) {
filenames3 <- list.files(directory, pattern = ".csv", full.names = TRUE)
loop_length <- length(filenames3)
correlation_values <- numeric()
for(i in loop_length) {
read_in_data3 <- read.csv(filenames3[i])
complete_boolean <- complete.cases(read_in_data3)
nobs2 <- sum(complete_boolean)
data_rmNA <- read_in_data3[complete_boolean, ]
if(nobs2 > threshold) {
correlation_values <- c(correlation_values,
cor(data_rmNA[["sulfate"]],
data_rmNA[["nitrate"]]))
}
}
correlation_values
}
corr("C:/Users/Danie/OneDrive/Documents/R/specdata")
I have tried specifying the length of the vector e.g. correlation_values <- numeric(length = loop_length). This returns a vector of the right length, but all the values are 0 excluding the last which runs properly. I have looked at similar questions, but still can't find a solution to my problem.
I assume I'm losing information in the loop somewhere (rewriting over a variable or something).
Thanks in advance for any help.
I think you need to say for(i in 1:loop_length) instead of for(i in loop_length).
R will loop over each element in the provided vector, but right now your vector is length 1 which is why only the last value is returned.

Using by in parallel in R

I am a noob R programmer. I have written a code that needs to apply a function to a data frame split by factors. The data frame in itself contains about 1 million 324961 observations with 64376 factors in the variable that we use to slice the dataframe.
The code is as follows:
library("readstata13")
# Reading the Stata Data file into R
bod_fb <- read.dta13("BoD_nonmissing_fb.dta")
gen_fuzzy_blau <- function(bod_sample){
# Here we drop the Variables that are not required in creating the Fuzzy-Blau index
bod_sample <- as.data.frame(bod_sample)
bod_sample$tot_occur <- as.numeric(bod_sample$tot_occur)
bod_sample$caste1_occ <- as.numeric(bod_sample$caste1_occ)
bod_sample$caste2_occ <- as.numeric(bod_sample$caste2_occ)
bod_sample$caste3_occ <- as.numeric(bod_sample$caste3_occ)
bod_sample$caste4_occ <- as.numeric(bod_sample$caste4_occ)
# Calculating the Probabilites of a director belonging to a caste
bod_sample$caste1_occ <- (bod_sample$caste1_occ)/(bod_sample$tot_occur)
bod_sample$caste2_occ <- (bod_sample$caste2_occ)/(bod_sample$tot_occur)
bod_sample$caste3_occ <- (bod_sample$caste3_occ)/(bod_sample$tot_occur)
bod_sample$caste4_occ <- (bod_sample$caste4_occ)/(bod_sample$tot_occur)
#Dropping the Total Occurances column, as we do not need it anymore
bod_sample$tot_occur<- NULL
# Here we replace all the blanks with NA
bod_sample <- apply(bod_sample, 2, function(x) gsub("^$|^ $", NA, x))
bod_sample <- as.data.frame(bod_sample)
# Here we push all the NAs in the caste names and caste probabilities to the end of the row
# So if there are only two castes against a name, then they become caste1 and caste2
caste_list<-data.frame(bod_sample$caste1,bod_sample$caste2,bod_sample$caste3,bod_sample$caste4)
caste_list = as.data.frame(t(apply(caste_list,1, function(x) { return(c(x[!is.na(x)],x[is.na(x)]) )} )))
caste_list_prob<-data.frame(bod_sample$caste1_occ,bod_sample$caste2_occ,bod_sample$caste3_occ,bod_sample$caste4_occ)
caste_list_prob = as.data.frame(t(apply(caste_list_prob,1, function(x) { return(c(x[!is.na(x)],x[is.na(x)]) )} )))
# Here we write two functions: 1. gen_castelist
# 2. gen_caste_prob
# gen_castelist: This function takes the row number (serial number of the direcor)
# and returns the names of all the castes for which he has a non-zero
# probability.
# gen_caste_prob: This function takes the row number (serial number of the director)
# and returns the probability with which he belongs to the caste
#
gen_castelist <- function(x){
y <- caste_list[x,]
y <- as.vector(y[!is.na(y)])
return(y)
}
gen_caste_prob <- function(x){
z <- caste_list_prob[x,]
z <- z[!is.na(z)]
z <- as.numeric(z)
return(z)
}
caste_ls <-list()
caste_prob_ls <- list()
for(i in 1:nrow(bod_sample))
{
caste_ls[[i]]<- gen_castelist(i)
caste_prob_ls[[i]]<- gen_caste_prob(i)
}
gridcaste <- expand.grid(caste_ls)
gridcaste <- data.frame(lapply(gridcaste, as.character), stringsAsFactors=FALSE)
gridcasteprob <- expand.grid(caste_prob_ls)
# Generating the Joint Probability
gridcasteprob$JP <- apply(gridcasteprob,1,prod)
# Generating the Similarity Index
gen_sim_index <- function(x){
x <- t(x)
a <- as.data.frame(table(x))
sim_index <- sum(a$Freq^2)/(sum(a$Freq))^2
return(sim_index)
}
gridcaste$sim_index <- apply(gridcaste,1,gen_sim_index)
# Generating fuzzyblau
gridcaste$fb <- gridcaste$sim_index * gridcasteprob$JP
fuzzy_blau_index <- sum(gridcaste$fb)
remove_list <- c("gridcaste","")
return(fuzzy_blau_index)
}
fuzzy_blau_output <- by(bod_fb,bod_fb$code_year,gen_fuzzy_blau)
# Saving the output as a dataframe with two columns
# Column 1 is the fuzzy blau index
# Column 2 is the code_year
code_year <- names(fuzzy_blau_output)
fuzzy_blau <- as.data.frame(as.vector(unlist(fuzzy_blau_output)))
names(fuzzy_blau) <- c("fuzzy_blau_index")
fuzzy_blau$code_year <- code_year
bod_fb <- merge(bod_fb,fuzzy_blau,by = "code_year")
save.dta13(bod_fb,"bod_fb_example.dta")
If the code is tl;dr, the summary is as follows:
I have a dataframe bod_fb. I need to apply the apply the gen_fuzzy_blau function on this dataframe by slicing the dataframe with factors of bod_fb$code_year.
Since the function is very huge sequential processing is taking more than a day and ends up in running out of memory. The function gen_fuzzy_blau returns a numeric variable fuzzy_blau_index for each code_year of the dataframe. I use by to apply the function on each slice. I wanted to know if there is a way to parallelly implement this code so that multiple instances of the function run at once on different slices of the dataframe. I did not find a by implementation for parallel package and I did not know how to pass the dataframes as iterators while using foreach and doParallel packages.
I have a AMD A8 laptop with 4GB RAM and windows 7 sp1 home basic. I have given 20GB as page file memory (this was after I got the memory error).
Thank you
EDIT 1: #milkmotel I have eliminated the redundancy in the code and removed the for loops, but a huge amount of time is being wasted in gen_sim_index in the function, I am using the proc.time()function to gauge the time that each part of the code is taking.
The function is supposed to the following to a row:
if we have a row (not a vector) say: a a b c the similarity index will be (2/4)^2 + (1/4)^2 + (1/4)^2 ie, summation of (no of occurences of each unique element of each row/total no of elements in the row)^2
I am unable to use the apply function directly on the row because each element in a row because each element in the row has different factors and table() does not output the frequencies properly.
What is an efficient way to code the gen_sim_index function?
You're saving your data 6 times over in 6 different variables. Try not doing that.
and it takes a day because you're running character indexing on a ridiculous amount of data with gsub().
Take your code out of your gen_fuzzy_blau function as it provides no value to wrap it up into one function rather than running it all independently. Then run it all one line at a time. If it takes too long to run, reconsider your method. Your code is incredibly inefficient.

Avoiding nested loops in R

I have this set of sequences with 2 variables for a 3rd variable(device). Now i want to break the sequence for each device into sets of 300. dsl is a data frame that contains d being the device id and s being the number of sequences of length 300.
First, I am labelling (column Sid) all the sequences rep(1,300) followed by rep(2,300) and so on till rep(s,300). Whatever remains unlabelled i.e. with initialized labels(=0) needs to be ignored. The actual labelling happens with seqid vector though.
I had to do this as I want to stack the sets of 300 data points and then transpose it. This would form one row of my predata data.frame. For each predata data frame i am doing a k-means to generate 5 clusters that I am storing in final data.
Essentially for every device I will have 5 clusters that I can then pull by referencing the row number in final data (mapped to device id).
#subset processed data by device
for (ds in 1:387){
d <- dsl[ds,1]
s <- dsl[ds,3]
temp.data <- subset(data,data$Device==d)
temp.data$Sid <- 0
temp.data[1:(s*300),4] <- rep(1:300,s)
temp.data <- subset(temp.data,temp.data$Sid!="0")
seqid <- NA
for (j in 1:s){ seqid[(300*(j-1)+1):(300*j)] <- j }
temp.data$Sid <- seqid
predata <- as.data.frame(matrix(numeric(0),s,600))
for(k in 1:s){
temp.data2 <- subset(temp.data[,c(1,2)], temp.data$Sid==k)
predata[k,] <- t(stack(temp.data2)[,1])
}
ob <- kmeans(predata,5,iter.max=10,algorithm="Hartigan-Wong")
finaldata <- rbind(finaldata,(unique(fitted(ob,method="centers"))))
}
Being a noob to R, I ended up with 3 nested loops (the function did work for the outermost loop being one value). This has taken 5h and running. Need a faster way to go about this.
Any help will be appreciated.
Thanks
Ok, I am going to suggest a radical simplification of your code within the loop. However, it is hard to verify that I in fact did assume the right thing without having sample data. So please ensure that my predata in fact equals yours.
First the code:
for (ds in 1:387){
d <- dsl[ds,1]
s <- dsl[ds,3]
temp.data <- subset(data,data$Device==d)
temp.data <- temp.data[1:(s*300),]
predata <- cbind(matrix(temp.data[,1], byrow=T, ncol=300), matrix(temp.data[,2], byrow=T, ncol=300))
ob <- kmeans(predata,5,iter.max=10,algorithm="Hartigan-Wong")
finaldata <- rbind(finaldata,(unique(fitted(ob,method="centers"))))
}
What I understand you are doing: Take the first 300*s elements from your subset(data, data$Devide == d. This might easily be done using the command
temp.data <- temp.data[1:(s*300),]
Afterwards, you collect a matrix that has the first row c(temp.data[1:300, 1], temp.data[1:300, 2]), and so on for all further rows. I do this using the matrix command as above.
I assume that your outer loop could be transformed in a call to tapply or something similar, but therefore, we would need more context.

Doing calculations on dataframe from ffdf object

Im working with a large dataset (3.5M lines and 40 columns) and I need to clean out some values so I´ll be able to calculate other parameters that I are necessary when I start formulating a model around the data.
The problem is that it is taking forever to apply the for loops that I have been using so I wanted to try to make use of the ff package. The dataframe is called data and it consists of bunch of customer information for a bank. It was imported as a .csv file. What I need to do is remove all customers (labeled Serial) if their AverageStanding variable is ever negative
> ffd<-as.ffdf(data)
> lastserial = tail(ffd$Serial,1)
> for(k in 1:lastserial){
+ tempvecWith <- vector()
+ tempvecWith <- ffd[ffd$Serial==k, ]$AverageStanding
+ if(any(tempvecWith < 0)){
+ ffd_clean<- ffd[!ffd$Serial ==k, ]
+ }
+ }
This is the error that I am receiving:
Error in as.hi.integer(x, maxindex = maxindex, dim = dim, vw = vw, pack = pack) :
NAs in as.hi.integer
Any ideas on how I can avoid these errors?
The error comes from this part of your code ffd[ffd$Serial==k, ]. Namely ffd$Serial==k returns an ff logical vector. But if you want to index or subset an ff vector or ffdf, you need to supply the index numbers, not a vector of logicals. You can turn your ff vector of logicals into an ff vector of index numbers by using ffwhich from package ffbase.
So for your questions, I believe you are looking for this kind of code (not tested as you did not supply any data).
require(ffbase)
idx <- ffd$AverageStanding < 0
idx <- ffwhich(idx, idx==TRUE)
open(ffd)
serials.with.negative <- ffd$Serial[idx]
serials.with.negative <- unique(serials.with.negative)
ffd$is.customer.with.negative.avgstanding <- ffd$Serial %in% serials.with.negative
idx <- ffd$is.customer.with.negative.avgstanding == FALSE
idx <- ffwhich(idx, idx==TRUE)
open(ffd)
ffd_clean <- ffd[idx, ]

Resources