I have a big data and I want subjects with test result <50 and to include subjects if the test result <150 one time only during their testing period. If the test result is <150 2x or more then the subject will not be need. For example, ID – 4 has 1 st test <50 but 2 test results <150 so the subject will not be need. How can I get those that have test<50 or test<150 one time only? ID test 1 50 1 45 1 78 2 34 2 26 3 67 4 22 4 120 4 69    This is how the output would look like ID test 1 50 1 45 1 78 2 34 2 26 3 67   ... View more

I have to data with the same variable name. I want to merge the data but, keep them in two separate columns.  Is it possible to match and merge? ID 2 3 5   ID  1 2 3 4 5   I would like to have an output that looks like this ID ID1 1   2 2 3 3 4   5 5 ... View more

I have a big data and I want to select specific records where the identified ID have a test result <=60 . I want to exclude if the subject "ID" has test result >60 during any time period from the analysis  ID date test 1 5/21/2019 43 1 8/15/2019 12 1 10/16/2020 20 2 8/4/2019 10 2 12/2/1019 70 3 5/21/2019 7 3 8/15/2019 60 4 1/6/1019 21 4 5/23/2019 33 4 8/5/2019 57   I want an output with ID that only have <=60 ID 1 3 ... View more

I have a data and I want to keep records where their test starts <=80 and, it doesn’t matter if the number is greater of less than after identifying the first obs that is <=80 ID test 1 100 1 70 1 200 2 85 2 350 2 65 3 80 3 75 3 120   ID test 1 70 1 200 2 65 3 80 3 75 3 120   ... View more

I have a data similar to this and I want to select the last visit for each individual. How would I do that? ID visit 1 5/3/20 1 7/2/20 2 8/9/21 3 1/5/20 3 4/18/20 3 8/23/20 4 6/8/20 4 10/9/20     I want an output like this (I don’t want to include those that have only one visit) ID visit 1 7/2/20 3 8/23/20 4 10/9/20 ... View more

I have a big data, and i wanted to select a few obs of a variable. How can I do that with big data? For example: I have a data similar to the table below   class ID D4 1 A6 2 F9 3 F9 4 C5 5 A6 6 R10 7 R10 8 R10 9   I want the output to look like this class ID A6 2 F9 3 F9 4 A6 6 R10 7 R10 8 R10 9 ... View more