Hi everyone,



I’m looking for a clever bit of code to replace NA’s with a specific score
depending on an indicator variable.



I can see how to do it using lots of if statements but I’m sure there most
be a neater, better way of doing it.



Any ideas at all will be much appreciated, I’m dreading coding up all those
if statements!!!!!





My problem is as follows:



I have a data set with lots of missing data:

EG Raw Data Set

Category         variable1         variable2         variable3

   1                   5                   NA
NA

   1                  NA
3                    4

   2                   NA
    7                   NA

  etc



Now I want to replace the NA’s with the average for each category, so if
these averages were:

EG Averages

Category         variable1         variable2         variable3

   1                  4.5
3.2                  2.5

   2                  3.5
    7.4                  5.9



So I’d like my data set to look like the following once I’ve replaced the
NA’s with the appropriate category average:

EG Imputed Data Set

Category         variable1         variable2         variable3

   1                   5                   3.2
2.5

   1                  4.5
3                    4

   2                  3.5
  7                   5.9

  etc





Any ideas would be very much appreciated!!!!!



thankyou





Chris Howden

Founding Partner

Tricky Solutions

Tricky Solutions 4 Tricky Problems

Evidence Based Strategic Development, IP development, Data Analysis,
Modelling, and Training

(mobile) 0410 689 945

(fax / office) (+618) 8952 7878

chris@(protected)

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