Combining Duplicates

[maria lolopez]

Hi,

I have observations on students and would like to combine duplicate students together. For example,

class	name	attendance	quiz_mean	final	exam1
bio101	AMAL	.037	.	.	.
bio101	AMAL	.	0	0	0
bio110	GABE	.	.73	.75	.53
bio110	GABE	.96	.	.	.

I would like it to look like this:

class	name	attendance	quiz_mean	final	exam1
bio101	AMAL	.037	0	0	0
bio110	GABE	.96	.73	.75	.53

I tried using:

replace quiz_mean = 0 if quiz_mean == . & name = "AMAL"

and it didn't work.

Any help is appreciated!

Thanks

[Ken Chui]

Welcome to Statalist. In future please use dataex to post data set that can be directly read into Stata. It'd save users here some time if they wish to test the code. Read the FAQ for more info (section 12).

clear
input str10 class str10     name     attendance     quiz_mean     final     exam1
bio101     AMAL     .037     .     .     .
bio101     AMAL     .     0     0     0
bio110     GABE     .     .73     .75     .53
bio110     GABE     .96     .     .     .
end

collapse (mean) attendance-exam1, by(class name)
list

Results:

     +-----------------------------------------------------+
     |  class   name   attend~e   quiz_m~n   final   exam1 |
     |-----------------------------------------------------|
  1. | bio101   AMAL       .037          0       0       0 |
  2. | bio110   GABE        .96        .73     .75     .53 |
     +-----------------------------------------------------+