In f0nzie/zFactor: Calculate the Compressibility Factor 'z' for Hydrocarbon Gases

Convert a list of data frames into one data frame

https://stackoverflow.com/q/2851327/5270873

listOfDataFrames <- vector(mode = "list", length = 100)

for (i in 1:100) {
    listOfDataFrames[[i]] <- data.frame(a=sample(letters, 500, rep=T),
                             b=rnorm(500), c=rnorm(500))
}

 df <- do.call("rbind", listOfDataFrames)

df_id <- data.table::rbindlist(listOfDataFrames, idcol = TRUE)
head(df_id)

merging several data frames into a single expanded frame

https://stackoverflow.com/a/4748770/5270873

data_list <- list()
data_list[["system1"]] <- read.table(tc <- textConnection("file    cumSize     cumloadTime     query1
1  ../data/data1.dat    100000      158.1000        0.4333333
2  ../data/data2.dat    200000      394.9000        0.5000000
3  ../data/data3.dat    250000      561.8667        0.6666667"), header = TRUE); close(tc)

data_list[["system2"]] <- read.table(tc <- textConnection("file    cumSize     cumloadTime     query1
1  ../data/data1.dat    100000      120.1000        0.4333333
2  ../data/data2.dat    200000      244.9000        0.4500000
3  ../data/data3.dat    250000      261.8667        0.2666667"), header = TRUE); close(tc)


for(n in names(data_list)) 
    data_list[[n]]$system <- n

all_data <- do.call(rbind, data_list)

p1 <- ggplot(all_data, aes(cumSize, cumloadTime, color = system)) + geom_line(); p1
p2 <- ggplot(all_data, aes(cumSize, query1, color = system)) + geom_line(); p2

https://stackoverflow.com/a/4749030/5270873

library(plyr)
library(reshape)
d2 <- ldply(data_list)
cast(d2, cumSize~.id, value_var="cumloadTime")
cast(d2, cumSize~.id, value_var="query1")
matplot(d2$cumSize, type="l")
matplot(d2$cumloadTime, type="l")

d3 <- melt(d2, measure=c("cumloadTime", "query1"))
ggplot(d3, aes(cumSize, value, colour=.id)) + geom_line() + 
  facet_wrap(~variable, nrow=2, scale="free_y")