na

I am new to R, and I don't understand yet completely the logic of its calculations... I cannot overcome my problem with the help from previous posts either. I have a data set of about 600 observations for 11 variables. I have successfully run the multinomial model on it, however I cannot achieve the marginal effects because my mean() command is getting NAs: The data set: > head(data,n=50) ID time CHINN DEBT ERA INFL MONEY OPENNESS RESERVES RGDP RSVS 1 POL 1993 -1.8639720 NA 0 32.8815343 33.47353 41.05223 4276726138 100.00000 4.2767261 2 POL 1994 -0.8081098 NA 0 30.7586977 31.98628 41.26984

R seems to support an efficient NA value in floating point arrays. How does it represent it internally? My (perhaps flawed) understanding is that modern CPUs can carry out floating point calculations in hardware, including efficient handling of Inf, -Inf and NaN values. How does NA fit into this, and how is it implemented without compromising performance? R uses NaN values as defined for IEEE floats to represent NA_real_ , Inf and NA . We can use a simple C++ function to make this explicit: Rcpp::cppFunction('void print_hex(double x) { uint64_t y; static_assert(sizeof x == sizeof y, "Size does

I am using the function prcomp to calculate the first two principal components. However, my data has some NA values and therefore the function throws an error. The na.action defined seems not to work even though it is mentioned in the help file ?prcomp Here is my example: d <- data.frame(V1 = sample(1:100, 10), V2 = sample(1:100, 10)) prcomp(d, center = TRUE, scale = TRUE, na.action = na.omit) d$V1[5] <- NA d$V2[7] <- NA prcomp(d, center = TRUE, scale = TRUE, na.action = na.omit) I am using the newest R version 2.15.1 for Mac OS X. Can anybody see the reason while prcomp fails? Here is my new

I'm reading in an Excel file using read.xlsx , and I would like to set na.strings as you can with read.table . Is this possible? It doesn't work to just add na.strings to the call like this: Data <- read.xlsx("my file.xlsx", sheetName = "MyData", na.strings = "no info") Is there some other way to do it? No this is not possible for the simple reason that read.xlsx doesn't take care of special missing values. But this can be a possible enhancement for getCellvalue function. You can either replace missing values using something like : Data[Data=="no info"] <- NA Or, transform your data to a csv

My first approach was to use na.strings="" when I read the data in from a csv. This doesn't work for some reason. I also tried: df[df==''] <- NA Which gave me an error: Can't use matrix or array for column indexing. I tried just the column: df$col[df$col==''] <- NA This converts every value in the entire dataframe to NA, even though there are values besides empty strings. Then I tried to use mutate_all : replace.empty <- function(a) { a[a==""] <- NA } #dplyr pipe df %>% mutate_all(funs(replace.empty)) This also converts every value in the entire dataframe to NA. I suspect something is weird

I am writing a function, which needs a check on whether (and which!) column (variable) has all missing values ( NA , <NA> ). The following is fragment of the function: test1 <- data.frame (matrix(c(1,2,3,NA,2,3,NA,NA,2), 3,3)) test2 <- data.frame (matrix(c(1,2,3,NA,NA,NA,NA,NA,2), 3,3)) na.test <- function (data) { if (colSums(!is.na(data) == 0)){ stop ("The some variable in the dataset has all missing value, remove the column to proceed") } } na.test (test1) Warning message: In if (colSums(!is.na(data) == 0)) { : the condition has length > 1 and only the first element will be used Q1: Why is

This question already has an answer here: filter for complete cases in data.frame using dplyr (case-wise deletion) 6 answers I tried to remove NA's from the subset using dplyr piping. Is my answer an indication of a missed step. I'm trying to learn how to write functions using dplyr: > outcome.df%>% + group_by(Hospital,State)%>% + arrange(desc(HeartAttackDeath,na.rm=TRUE))%>% + head() Source: local data frame [6 x 5] Groups: Hospital, State Hospital State HeartAttackDeath 1 ABBEVILLE AREA MEDICAL CENTER SC NA 2 ABBEVILLE GENERAL HOSPITAL LA NA 3 ABBOTT NORTHWESTERN HOSPITAL MN 12.3 4 ABILENE