R scan() Function - Reading Data
R Language ExamplesThe R scan() function is used to read data from a file or keyboard into a vector.
Unlike read.table(), scan() directly returns a vector rather than a data frame, making it suitable for reading numeric data streams.
The syntax of the scan() function is as follows:
scan(file = "", what = double(), n = -1, sep = "", quiet = FALSE)
Parameter description:
fileFile path. When it is an empty string, reads from the keyboard.
whatData type, such as numeric() or character().
nNumber of elements to read; -1 means read all.
sepSeparator.
Example
# First prepare a data file
writeLines(c("10 20 30", "40 50 60"), "temp_data.txt")
# Use scan to read numeric values
data <- scan("temp_data.txt")
print("Read values:")
print(data)
print(paste("Sum:", sum(data)))
print(paste("Mean:", mean(data)))
# scan can also read strings directly
writeLines(c("Chinese Math English Physics Chemistry"), "temp_subjects.txt")
subjects <- scan("temp_subjects.txt", what = character())
print("Read strings:")
print(subjects)
writeLines(c("10 20 30", "40 50 60"), "temp_data.txt")
# Use scan to read numeric values
data <- scan("temp_data.txt")
print("Read values:")
print(data)
print(paste("Sum:", sum(data)))
print(paste("Mean:", mean(data)))
# scan can also read strings directly
writeLines(c("Chinese Math English Physics Chemistry"), "temp_subjects.txt")
subjects <- scan("temp_subjects.txt", what = character())
print("Read strings:")
print(subjects)
Executing the above code outputs the following result:
Read 6 items [1] "读取的数值:" [1] 10 20 30 40 50 60 [1] "总和: 210" [1] "均值: 35" Read 5 items [1] "读取的字符串:" [1] "语文" "数学" "英语" "物理" "化学"Other extensions