When using chmod -R o+rx /data , you set the execute permission on all directories as well as files in the /data directory. To set the execute permission to directories only, and not to files, use chmod -R o+rX /data . The uppercase X ensures that
Merging Data Adding Columns To merge two data frames (datasets) horizontally, use the merge function. In most cases, you join two data frames by one or more common key variables (i.e., an inner join). # merge two data frames by ID total <- merge(
Reading Data There are a few principal functions reading data into R. read.table, read.csv, for reading tabular data readLines, for reading lines of a text file source, for reading in R code files (inverse of dump) dget, for reading in R code files (
data.frame比较像表格,每一列是一个向量,即每列中的元素是同一类型:所有列具有相同的长度. x = 10:1 y = -4:5 q = c("Ha","oh","wow","yes","Noooo","wasami","cuckoo","sweet","candy","gloss") df1 = da
Around September of 2016 I wrote two articles on using Python for accessing, visualizing, and evaluating trading strategies (see part 1 and part 2). These have been my most popular posts, up until I published my article on learning programming langua
目录 select The filter and arrange verbs arrange filter Filtering and arranging Mutate The count verb Summarizing top_n Selecting rename transmute Grouped mutates Window functions Data Manipulation with dplyr in R select select(data,变量名) The filter and
window下导入数据: LOAD DATA INFILE "C:\\1.csv" REPLACE INTO TABLE demo CHARACTER SET gb2312 FIELDS TERMINATED BY "," ENCLOSED BY "" LINES TERMINATED BY "\r\n"; window下导出数据