tsvファイルを読み込んで、日付文字列をYY-MM-DDに変換するというプログラム。
ソースファイルから実行するときはsourceを使う。
tsvを読み込んで、DateOccurredとDateReportedをYY-MM-DDに変換することが出来た。
> source("data_cleaning.R") > head(ufo) DateOccurred DateReported Location ShortDescription Duration 1 1995-10-09 1995-10-09 Iowa City, IA <NA> <NA> 2 1995-10-10 1995-10-11 Milwaukee, WI <NA> 2 min. 3 1995-01-01 1995-01-03 Shelton, WA <NA> <NA> 4 1995-05-10 1995-05-10 Columbia, MO <NA> 2 min. 5 1995-06-11 1995-06-14 Seattle, WA <NA> <NA> 6 1995-10-25 1995-10-24 Brunswick County, ND <NA> 30 min. LongDescription 1 Man repts. witnessing "flash, followed by a classic UFO, w/ a tailfin at back." Red color on top half of tailfin. Became triangular. 2 Man on Hwy 43 SW of Milwaukee sees large, bright blue light streak by his car, descend, turn, cross road ahead, strobe. Bizarre! 3 Telephoned Report:CA woman visiting daughter witness discs and triangular ships over Squaxin Island in Puget Sound. Dramatic. Written report, with illustrations, submitted to NUFORC. 4 Man repts. son's bizarre sighting of small humanoid creature in back yard. Reptd. in Acteon Journal, St. Louis UFO newsletter. 5 Anonymous caller repts. sighting 4 ufo's in NNE sky, 45 deg. above horizon. (No other facts reptd. No return tel. #.) 6 Sheriff's office calls to rept. that deputy, 20 mi. SSE of Wilmington, is looking at peculiar, bright white, strobing light.