Creating a rank numeric variable from a string alphabetic variable

[Danish Salam]

Hi everyone,

Please find below data from a survey that asks participants to complete tasks A, B, C, D, E, F, G, H and I. The order in which these tasks were displayed to the participants was random.

1) The variable "uid" refers to participant id.
2) Variable "order" shows the order in which the tasks were displayed. For example, for participant 12216214, the 7th task was "A", whereas for participant 12216185 the 3rd task was "A"

Is there a way I can create a numeric variable (say "task_number") that captures the order number of the task for each individual and task.

For example, for scenario A, I want the variable to look like the following, see table below:

uid	order	task	task_number
12216214	DECFBGAHI	A	7
12216185	BCADIEHFG	A	3
12216186	ABICHDGEF	A	1
12216247	EFDGCHBIA	A	9
12216232	FGEHDICAB	A	8

Any help on this will be highly appreciated.

	
	
* Example generated by -dataex-. For more info, type help dataex
clear
input long uid str9 order str1 task
12216214 "DECFBGAHI" "A"
12216185 "BCADIEHFG" "A"
12216186 "ABICHDGEF" "A"
12216247 "EFDGCHBIA" "A"
12216232 "FGEHDICAB" "A"
12216214 "GHFIEADBC" "B"
12216185 "BCADIEHFG" "B"
12216186 "DECFBGAHI" "B"
12216247 "HIGAFBECD" "B"
12216232 "CDBEAFIGH" "B"
12216214 "CDBEAFIGH" "C"
12216185 "EFDGCHBIA" "C"
12216186 "FGEHDICAB" "C"
12216247 "GHFIEADBC" "C"
12216232 "HIGAFBECD" "C"
12216214 "BCADIEHFG" "D"
12216185 "IAHBGCFDE" "D"
12216186 "CDBEAFIGH" "D"
12216247 "DECFBGAHI" "D"
12216214 "ABICHDGEF" "D"
12216185 "FGEHDICAB" "E"
12216186 "GHFIEADBC" "E"
12216247 "HIGAFBECD" "E"
12216232 "IAHBGCFDE" "E"
       . ""          ""
end

[George Ford]

g rank = strpos(order,task)

[Nick Cox]

clear 
input long uid    str9 order    str1 task    task_number
12216214    DECFBGAHI    A    7
12216185    BCADIEHFG    A    3
12216186    ABICHDGEF    A    1
12216247    EFDGCHBIA    A    9
12216232    FGEHDICAB    A    8
end 

foreach x in A B C D E F G H I { 
    gen num`x' = strpos(order, "`x'")
}

list order num* 

     +--------------------------------------------------------------------------+
     |     order   numA   numB   numC   numD   numE   numF   numG   numH   numI |
     |--------------------------------------------------------------------------|
  1. | DECFBGAHI      7      5      3      1      2      4      6      8      9 |
  2. | BCADIEHFG      3      1      2      4      6      8      9      7      5 |
  3. | ABICHDGEF      1      2      4      6      8      9      7      5      3 |
  4. | EFDGCHBIA      9      7      5      3      1      2      4      6      8 |
  5. | FGEHDICAB      8      9      7      5      3      1      2      4      6 |
     +--------------------------------------------------------------------------+

[Nick Cox]

Although I think I showed you something relevant, and George Ford clearly had exactly the same idea, I am still puzzled at exactly what you want. You could pack all those orders into a single variable using concatenation, but I don't see that that would be more useful, and it would not be more informative.