Extract value of a variable and insert into string variable in the same observation

[ram singh]

Dear Statalisters

For an example dataset like so

* Example generated by -dataex-. To install: ssc install dataex
clear
input float(teacher students) str42 statement
1  50 ""
2 100 ""
end

I want to extract the value of variable "students" and insert it into a string variable "statement" something like below

command
replace statement = "This Teacher has `=students[_n]' students in her class"
(2 real changes made)


But rather than getting the respective values I am getting the value of the first observation in both first and second obs.

* Example generated by -dataex-. To install: ssc install dataex
clear
input float(teacher students) str42 statement
1  50 "This Teacher has  50 students in her class"
2 100 "This teacher has  50 students in her class"
end

On the other hand I want to get

* Example generated by -dataex-. To install: ssc install dataex
clear
input float(teacher students) str43 statement
1  50 "This Teacher has  50 students in her class"
2 100 "This Teacher has 100 students in her class"
end

Thanks in advance for any help.

[Andrew Musau]

gen statement = "This teacher has " + string(students)+ " students in her class"

[ram singh]

Thanks a lot Andrew !

Also just for my knowledge referencing the way I was doing is illegal and defaults to the first obs .. right ?

regards

[Nick Cox]

There was nothing illegal about what you did -- that would have entailed an error message -- just that it wasn't what you wanted.

References within commands to local macros and to items with local macro personas are always interpreted just once and before any calculations take place. They won't be interpreted according to the values in each observation. As you say, Stata when faced with a reference of this kind will use the value in the first observation.

[ram singh]

thanks Nick, much appreciated.
kind regards