因為最近開始使用SAS，順便考SAS BASE 不過太久沒碰的下場就是好多東西都忘記了.... 想請問以下幾個題目，希望強者能夠提供一些見解(跪) 1. data work.test; capacity = 150; if 100 le capacity le 200 then airplanetype = 'large' and staff = 10; else airplanetype = 'small' and staff = 5; run; 題目希望data set 長成如下，上面這個是錯的，只是我不確定錯在哪裡 capacity airplanetype staff 150 large 10 就題目而言，是因為else 少了一個if嗎？ 另外就是if-then的語法裡面，如果有假設三個if-then的時候 一般都是打成if-then else if-then else (最後這個就不用加上？） 2.submit following libname sasdata ' ' data allobs; set sasdata.banks; capital = 0; do year = 2000 to 2020 by 5; capital+((capital+2000)*rate); output; end; run; if sasdata.banks has five observation，how many observations will the ALLOBS contain? Ans:25 這個我就掉到五里霧裡面了.... 另外一個疑問是，output的使用時機，雖然講義上面是寫prevent continuous looping， 但感覺有一點抽象，另外是不是用了output，後面一定要用stop; ? 3.submit following data work.XXX set work.people (in = inemp) work.money (in = insal); if insal = inemp; run; work.people has 5 observations, and work.money has 7 observations How many obs contain in work.XXXX? Ans: 0 因為這應該是一個concatenating，為什麼不是12個 obs? 4. 在從外部抓資料的時候 input style $ @; style是一個variable的名字，但後面的＠代表什麼意義？ 因為我看到的都是input @4 style $2.;類似這種的，但＠在後面的有特別意義嗎？ 5. data work.total; infile where end = eof; input name $ salary; total + salary; (if statement) run; which statement would write the last observation to the output data set? Ans: if eof = 1; 不太了解題意，最後想問一下if如果再沒有then的搭配下，跟where statement有什麼 差別呢？ 我想對大家來說這些都是很簡單的問題，還請大家不賜吝教，感恩 -- "When someone sees you as you really are and wants to be with you ,that's powerful." --

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