naturalconan的专栏

1. Reading Data read.table (If large dataset, provide colClasses and nrows) read.csv readLines source dget load unserialize  2. File Connections str(file) - r - w - a - rb, wb, ab co

1. Input and Evaluation assign: x comment: # x print: print(x) 2. Objects and Attributes objects: - character - numeric - integer - complex - logical vector- objects of same classes: x

1.str function structure of the object 2. Simulation d for density r for random number generation p for cumulative distribution q for quantile function dnorm(x, mean = 0, sd = 1, log =

1. If-else y 3){ 10 }else{ 0 } 2. for x for(i in 1:4) { print(x[i]) } for(i in seq_along(x)){ print(x[i]) } for(letter in x){ print(letter) } 3. while count while(count

Loop Function: lapply - loop the list and evaluate a function on each element always return a list sapply - simplify the result same as lapply apply: over the margins of an array(dimension) tapply