Hi everyone,   I got a question about using 2 SETs to combine 2 datasets. My question came from the Little SAS Book (5th ed) on page 12/27: Combining a Grand Total with the Original Data.       To make it easier to understand, I copy the whole programming:   A distributor of athletic shoes is considering doing a special promotion for the top-selling styles. The vice-president of marketing asks you to produce a report showing the percentage of total sales for each style. For each style of shoe the raw data file contains the style name, type of exercise, and sales for the last quarter:   Max Flight      running 1930 Zip Fit Leather walking 2250 Zoom Airborne   running 4150 Light Step      walking 1130 Max Step Woven  walking 2230 Zip Sneak       c-train 1190   Here is the program:   DATA shoes; INFILE 'c:\MyRawData\Shoesales.dat'; INPUT Style $ 1-15 ExerciseType $ Sales; RUN;   * Output grand total of sales to a data set and print; PROC MEANS NOPRINT DATA = shoes; VAR Sales; OUTPUT OUT = summarydata SUM(Sales) = GrandTotal; RUN; PROC PRINT DATA = summarydata; TITLE 'Summary Data Set'; RUN;   * Combine the grand total with the original data; DATA shoesummary; IF _N_ = 1 THEN SET summarydata; SET shoes; Percent = Sales / GrandTotal * 100; RUN; PROC PRINT DATA = shoesummary; VAR Style ExerciseType Sales GrandTotal Percent; TITLE 'Overall Sales Share'; RUN; ---------------------- My question is in the last part (Combine the grand total with the original data):   DATA shoesummary; IF _N_ = 1 THEN SET summarydata; SET shoes; Percent = Sales / GrandTotal * 100;   I do'nt quite understand why "IF _N_ = 1 THEN SET summarydata" is used here (although it works beautifully), why don't just simply use my simple version like this:   DATA shoesummary; SET summarydata; SET shoes; Percent = Sales / GrandTotal * 100;   Of course, my simple version does not work.    The dataset summarydata has only 1 line of observation, "IF _N_ = 1 THEN SET summarydata" will copy the whole dataset, my simple version will also copy the whole dataset. They are supposed to be the same, in my opinion, but actually NOT. Then what's the difference between them? is there any special reason to use "IF _N_ = 1 THEN SET summarydata" ?   (if this question sounds to be too silly, please forgive me)   Thanks. ... View more

Hi everyone,   I got a question about reading raw data:   ----+----1----+----2 1 22 333 4444 55555   I used following codes with a fixed width of 5. data numbers; infile 'external-file'; input testnum 5.; run; the output result is: 22 4444 55555 I don't understand this output.   First line has only 1 digit, plus 2nd line (2 digits), still not enough, right? I guess it goes to 3 line, ok! but why it picks up only 22, instead of pick them up together? (eg. 12233). For the remaining 2 lines it's the same way to read, it should get 44445. So my expectation is:   12234 44445   am I correct? or where is the problem?   Thanks.   Mike, ... View more