Combine Membership and csize of clusters in R - r

My Initial Data:
library(igraph)
From <- c(1,2,3,4,5,6,7,8)
To <- c(NA,1,2,3,2,NA,6,7)
Value<- c(1,0,0.5,0.5,0,-1,-1,-0.5)
Data <- data.frame(From,To, Value)
Network <- graph.data.frame(Data[,c("From","To")])
Network<- Network - "NA"
plot(Network)
I want to know the size of the cluster they belong to. I want to combine the two functions clusters()$membership and clusters()$csize but i have no idea how i could. I want to have the belonging cluster size on each row.
Clusterx<-clusters(Network)$membership
ClusterSize<-clusters(Network)$csize
Example of possible final Data:
From <- c(1,2,3,4,5,6,7,8)
To <- c(NA,1,2,3,2,NA,6,7)
Value<- c(1,0,0.5,0.5,0,-1,-1,-0.5)
Csize<- c(5,5,5,5,5,3,3,3)
Data <- data.frame(From,To, Value,Csize)

This is a simple indexing operation.
clu <- clusters(Network)
clu$csize[ clu$membership ]
# [1] 5 5 5 5 5 3 3 3

Related

connecting groups of duplicates

I have some data which has lots of duplication. For example, this data frame shows IDs in the data set that are known to be identical (e.g. row1 indicates a =b, therefore the rest of the data indicate that a=b=c and d=e=f):
a <- c('a','a','b','b','c','c','d','d','e','e','f','f')
b <- c('b','c','a','c','a','b','e','f','d','f','d','e')
duplicates <- cbind(a,b)
Is there any easy way to split these into two groups that are true IDs (e.g. here a,b & c are all the same and d,e & f are also all the same). So for my sample data:
a <- c('a','b','c','d','e','f')
b <- c('c1','c1','c1','c2','c2','c2')
new_id <- cbind(a,b)
The actual data has thousands of rows and is not fully connected (i.e. in a cluster of duplicates this could occur: a=b, a=c,b=/=c), due to some errors in duplicate detection.
Sounds like you are looking at network analyses. There are a few packages that deal with this. So you might want to use the one you are the most familiar with (network, tidygraph, igraph, diagrammeR). I use igraph, because I know that one a bit more than the others.
Steps:
First create a graph from the data using the dup data.frame. Next use the clusters function (or one of the other cluster options) to create clusters based on the data. Last step is to transform the clusters into a data.frame. Additionally you could plot the data (depends on how much data you have).
library(igraph)
g <- graph_from_data_frame(dup, directed = FALSE)
clust <- clusters(g)
clusters <- data.frame(name = names(clust$membership),
cluster = clust$membership,
row.names = NULL,
stringsAsFactors = FALSE)
clusters
name cluster
1 a 1
2 b 1
3 c 1
4 d 2
5 e 2
6 f 2
# plot graph if needed
plot(g)
data:
a <- c('a','a','b','b','c','c','d','d','e','e','f','f')
b <- c('b','c','a','c','a','b','e','f','d','f','d','e')
dup <- data.frame(a,b, stringsAsFactors = FALSE)
You could work with factors.
df.1$id <- with(df.1, ifelse(as.numeric(a) %in% 1:3, "c1", "c2"))
new_id <- unique(df.1[, -2])
rownames(new_id) <- NULL # just in case
Yielding
> new_id
a id
1 a c1
2 b c1
3 c c1
4 d c2
5 e c2
6 f c2
Data
a <- c('a','a','b','b','c','c','d','d','e','e','f','f')
b <- c('b','c','a','c','a','b','e','f','d','f','d','e')
df.1 <- data.frame(a, b)

Beta estimation over panel data by group

I found some previous questions on this topic especially this R: Grouped rolling window linear regression with rollapply and ddply and R: Rolling / moving avg by group , however, both questions did not provide an exact solution for the problem that I am facing. I am currently trying to estimate CAPM beta over panel data using a linear regression. So I have different funds (in the example below I used 3 fund groups) for which I would like to calculate the betas separately and per row. To put this more abstract: I am trying to do a linear regression with a moving window by group to estimate the coefficient for every row based on the data in the window.
install.packages("zoo","dplyr")
library(zoo);library(dplyr)
# Create dataframe
fund <- as.numeric(c(1,1,1,1,1,1,1,1,3,3,3,3,3,3,2,2,2,2,2,2,2))
return<- as.numeric(c(1:21))
benchmark <- as.numeric(c(1,13,14,20,14,32,4,1,5,7,1,0,7,1,-2,1,6,-7,9,10,9))
riskfree<-as.numeric(c(1,5,1,2,1,6,4,7,5,-5,10,0,3,1,2,1,6,7,8,9,10))
date <- as.Date(c("2010-07-30","2010-08-31","2010-09-30","2010-10-31","2010-11-30","2010-12-31","2011-01-30",
"2011-02-28","2010-07-31","2010-09-30","2010-10-31","2010-11-30","2010-12-31","2011-01-30",
"2010-07-30","2010-08-31","2010-09-30","2010-10-31","2010-11-30","2010-12-31","2011-01-30"))
funddata<-data.frame(date,fund,return,benchmark,riskfree)
# Creating variables of interest
funddata["ret_riskfree"]<-as.numeric(funddata$return-funddata$riskfree)
funddata["benchmark_riskfree"]<-as.numeric(funddata$benchmark-funddata$riskfree)
I want to do a rolling regression over two columns df[6:7] for every group indicated by the column "fund". The calculation should be done separately so the first two rows in the beta column for every fund group will always show "NA". In the end I want to have a full dataframe with all fund groups and all beta values combined.
I managed to come up with a new code that works but is pretty messy and it requires to order the data by fund & date before executing. I would welcome any suggestions on how to make it better.
funddata <- funddata[order(funddata$fund, funddata$date),]
beta_func <- function(x, benchmark_riskfree, ret_riskfree) {
a <- coef(lm(as.formula(paste(ret_riskfree, "~", benchmark_riskfree,-1)),
data = x))
return(a)
}
beta_list<-list()
for (i in c(1:3)){beta_list[[paste(i, sep="_")]]<- (rollapplyr(funddata[(funddata$fund==i),6:7], width = 3,
FUN = function(x) beta_func(as.data.frame(x), "benchmark_riskfree" , "ret_riskfree"),
by.column = FALSE,fill=NA))}
beta_list<-unlist(beta_list, recursive=FALSE)
funddata$beta<-beta_list
As I mentioned in the comment above, this solution might be a bit off since I'm not able to reproduce your desired output 100%. Still, the functionality of what you're trying to accomplish is there. Have a look at it and let me know if this is something you could use or I could develop further.
EDIT: The code below does not reproduce the desired output as specified above, but turned out to be what the OP was looking for after all.
Here goes:
# Datasource
fund <- as.numeric(c(1,1,1,1,1,1,1,1,3,3,3,3,3,3,2,2,2,2,2,2,2))
return<- as.numeric(c(1:21))
benchmark <- as.numeric(c(1,13,14,20,14,32,4,1,5,7,1,0,7,1,-2,1,6,-7,9,10,9))
riskfree<-as.numeric(c(1,5,1,2,1,6,4,7,5,-5,10,0,3,1,2,1,6,7,8,9,10))
date <- as.Date(c("2010-07-30","2010-08-31","2010-09-30","2010-10-31","2010-11-30","2010-12-31","2011-01-30",
"2011-02-28","2010-07-31","2010-09-30","2010-10-31","2010-11-30","2010-12-31","2011-01-30",
"2010-07-30","2010-08-31","2010-09-30","2010-10-31","2010-11-30","2010-12-31","2011-01-30"))
funddata<-data.frame(date,fund,return,benchmark,riskfree)
# Creating variables of interest
funddata["ret_riskfree"]<-as.numeric(funddata$return-funddata$riskfree)
funddata["benchmark_riskfree"]<-as.numeric(funddata$benchmark-funddata$riskfree)
# Target check #################################################################
# Subset last three rows in original dataframe
df_check <- funddata[funddata$fund == 1,]
df_check <- tail(df_check,3)
# Run regression check
mod_check <- lm(df_check$ret_riskfree~df_check$benchmark_riskfree)
coef(mod_check)
# My suggestion ################################################################
# The following function takes three arguments:
# 1. a dataframe, myDf
# 2. a column that you'd like to myDf on
# 3. a window length for a sliding window, myWin
fun_rollreg <- function(myDf, subCol, varY, varX, myWin){
df_main <- myDf
# Make an empty data frame to store results in
df_data <- data.frame()
# Identify unique funds
unFunds <- unique(unlist(df_main[subCol]))
# Loop through your subset
for (fundx in unFunds){
# Subset
df <- df_main
df <- df[df$fund == fundx,]
# Keep a copy of the original until later
df_new <- df
# Specify a container for your beta estimates
betas <- c()
# Specify window length
wlength <- myWin
# Retrieve some data dimensions to loop on
rows = dim(df)[1]
periods <- rows - wlength
# Loop through each subset of the data
# and run regression
for (i in rows:(rows - periods)){
# Split dataframe in subsets
# according to the window length
df1 <- df[(i-(wlength-1)):i,]
# Run regression
beta <- coef(lm(df1[[varY]]~df1[[varX]]))[2]
# Keep regression ressults
betas[[i]] <- beta
}
# Add regression data to dataframe
df_new <- data.frame(df, betas)
# Keep the new dataset for later concatenation
df_data <- rbind(df_data, df_new)
}
return(df_data)
}
# Run the function:
df_roll <- fun_rollreg(myDf = funddata, subCol = 'fund',
varY <- 'ret_riskfree', varX <- 'benchmark_riskfree',
myWin = 3)
# Show the results
print(head(df_roll,8))
For the first 8 rows in the new dataframe (fund = 1), this is the result:
date fund return benchmark riskfree ret_riskfree benchmark_riskfree betas
1 2010-07-30 1 1 1 1 0 0 NA
2 2010-08-31 1 2 13 5 -3 8 NA
3 2010-09-30 1 3 14 1 2 13 0.10465116
4 2010-10-31 1 4 20 2 2 18 0.50000000
5 2010-11-30 1 5 14 1 4 13 -0.20000000
6 2010-12-31 1 6 32 6 0 26 -0.30232558
7 2011-01-30 1 7 4 4 3 0 -0.11538462
8 2011-02-28 1 8 1 7 1 -6 -0.05645161

Gathering column names from data frame into a list in R

so I have a working data frame right now, but I would like to study the origins of the subjects of the data frame. Here is some of the code I used to create the data frame:
df <- as.data.frame(t(test)) #This is so the row names are products
vertices <- row.names(df)
place <- colnames(df)
L <- length(vertices)
numedges <- choose(L,2)
edges <- data.frame(v1=rep(NA, numedges), v2=NA, numrows=NA, location=NA)
k <- 0
for(i in 1:(L-1)) {
for(j in (i+1):L) {
k <- k + 1
edges$v1[k] <- vertices[i]
edges$v2[k] <- vertices[j]
edges$numrows[k] <- sum(df[vertices[i], ]=="Yes" & df[vertices[j], ]=="Yes")
edges$location[k] ### Here is my problem!!!
}}
And I would like the output to look something like:
edges
v1 v2 numrows location #What I would like to see
1 Fish Squid 8 Town 1, Town 2, Town 4
2 Fish Fruits 0 Town 1
3 Fish Wood 0 Town 1
4 Fish Etc 2 Town 1, Town 2
5 Fish Corn 1 Town 1
I think numrows becomes the sum of all the edges? Please correct me if I'm wrong. So then I wanted to gather all the locations where the numrow function was satisfied.
The question is unclear. You don't know how to add an attribute to a graph edge? For example to add an attribute location you simply do this:
E(g)$location=colnames(df) ## g is your graph
You can check this using
get.edge.attribute(g, 'location')
For example, I can use the attribute location to set the label of edge.
library(igraph)
g <- graph.ring(5)
V(g)$size <- 5
E(g)$location=paste(letters[1:5],LETTERS[1:5],sep=':')
E(g)$label <- get.edge.attribute(g, 'location')
E(g)$label.cex <- 2
plot(g)

Elements within lists.

I'm relatively new in R (~3 months), and so I'm just getting the hang of all the different data types. While lists are a super useful way of holding dissimilar data all in one place, they are also extremely inflexible for function calls, and riddle me with angst.
For the work I'm doing, I often uses lists because I need to hold a bunch of vectors of different lengths. For example, I'm tracking performance statistics of about 10,000 different vehicles, and there are certain vehicles which are so similar they can essentially be treated as the same vehicles for certain analyses.
So let's say we have this list of vehicle ID's:
List <- list(a=1, b=c(2,3,4), c=5)
For simplicity's sake.
I want to do two things:
Tell me which element of a list a particular vehicle is in. So when I tell R I'm working with vehicle 2, it should tell me b or [2]. I feel like it should be something simple like how you can do
match(3,b)
> 2
Convert it into a data frame or something similar so that it can be saved as a CSV. Unused rows could be blank or NA. What I've had to do so far is:
for(i in length(List)) {
length(List[[i]]) <- max(as.numeric(as.matrix(summary(List)[,1])))
}
DF <- as.data.frame(List)
Which seems dumb.
For your first question:
which(sapply(List, `%in%`, x = 3))
# b
# 2
For your second question, you could use a function like this one:
list.to.df <- function(arg.list) {
max.len <- max(sapply(arg.list, length))
arg.list <- lapply(arg.list, `length<-`, max.len)
as.data.frame(arg.list)
}
list.to.df(List)
# a b c
# 1 1 2 5
# 2 NA 3 NA
# 3 NA 4 NA
Both of those tasks (and many others) would become much easier if you were to "flatten" your data into a data.frame. Here's one way to do that:
fun <- function(X)
data.frame(element = X, vehicle = List[[X]], stringsAsFactors = FALSE)
df <- do.call(rbind, lapply(names(List), fun))
# element vehicle
# 1 a 1
# 2 b 2
# 3 b 3
# 4 b 4
# 5 c 5
With a data.frame in hand, here's how you could perform your two tasks:
## Task #1
with(df, element[match(3, vehicle)])
# [1] "b"
## Task #2
write.csv(df, file = "outfile.csv")

Easy Way to Get Averages Based on Names in List

Is there any easy way to get the averages of items in a list based on their names? Example dataset:
sampleList <- list("a.1"=c(1,2,3,4,5), "b.1"=c(3,4,1,4,5), "a.2"=c(5,7,2,8,9), "b.2"=c(6,8,9,0,6))
sampleList
$a.1
[1] 1 2 3 4 5
$b.1
[1] 3 4 1 4 5
$a.2
[1] 5 7 2 8 9
$b.2
[1] 6 8 9 0 6
What I am trying to do is get column averages between similarly but not identically named rows, outputting a list with the column averages for the a's and b's. Currently I can do the following:
y <- names(sampleList)
y <- gsub("\\.1", "", y)
y <- gsub("\\.2", "", y)
y <- sort(unique(y))
sampleList <- t(as.matrix(as.data.frame(sampleList)))
t <- list()
for (i in 1:length(y)){
temp <- sampleList[grep(y[i], rownames(sampleList)),]
t[[i]] <- apply(temp, 2, mean)
}
t
[[1]]
[1] 3.0 4.5 2.5 6.0 7.0
[[2]]
[1] 4.5 6.0 5.0 2.0 5.5
A I have a large dataset with a large number of sets of similar names, is there an easier way to go about this?
EDIT: I've broken out the name issue into a separate question. It can be found here
Well, this is shorter. You didn't say exactly how big your actual data is, so I"m not going to make any promises, but the performance of this shouldn't be terrible:
dat <- do.call(rbind,sampleList)
grp <- substr(rownames(dat),1,1)
aggregate(dat,by = list(group = grp),FUN = mean)
(Edited to remove the unnecessary conversion to a data frame, which will incur a significant performance hit, probably.)
If your data is crazy big, or even just medium-big but the number of groups is fairly large so there are a small number of vectors in each group, the standard recommendation would be to investigate data.table once you've rbinded the data into a matrix.
I might do something like this:
# A *named* vector of patterns you want to group by
patterns <- c(start.a="^a",start.b="^b",start.c="^c")
# Find the locations of those patterns in your list
inds <- lapply(patterns, grep, x=names(sampleList))
# Calculate the mean of each list element that matches the pattern
out <- lapply(inds, function(i)
if(l <- length(i)) Reduce("+",sampleList[i])/l else NULL)
# Set the names of the output
names(out) <- names(patterns)

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