type mismatch double and str18

[Jay Rege]

Hey,
I have a type mismatch Problem with the variable Bevölkerungswachstum_2007 which is str18 and the variable Bevölkerungswachstum_2006 which is double, since I want to generate a variable which combines values out of both variables I Need to know which Format Bevölkerungswachstum_Projektjahr Needs.

generate double Bevölkerungswachstum_Projektjahr = .
replace Bevölkerungswachstum_Projektjahr = Bevölkerungswachstum_2005 if date_Ideenwettbewerb == 2005
replace Bevölkerungswachstum_Projektjahr = Bevölkerungswachstum_2005 if inrange((Projektbeginn), mdy(01, 01, 2005), mdy(12, 31, 2005))
replace Bevölkerungswachstum_Projektjahr = Bevölkerungswachstum_2006 if date_Ideenwettbewerb == 2006
replace Bevölkerungswachstum_Projektjahr = Bevölkerungswachstum_2006 if inrange((Projektbeginn), mdy(01, 01, 2006), mdy(12, 31, 2006))
replace Bevölkerungswachstum_Projektjahr = Bevölkerungswachstum_2007 if date_Ideenwettbewerb == 2007
replace Bevölkerungswachstum_Projektjahr = Bevölkerungswachstum_2007 if inrange((Projektbeginn), mdy(01, 01, 2007), mdy(12, 31, 2007))

If you Need further Information do not hesitate to ask!
Thanks

[Nick Cox]

It seems that

Bevölkerungswachstum_2007

is str18 but similar variables are double. You could try destring (you may need to use its format() option) but there may be an underlying problem which explains why that variable is different.

[Sergiy Radyakin]

Jay, function year() will extract the year from a date variable.

clear

input str20 pb
"30/03/2005"
"13/12/2007"
"01/01/2006"
end

generate d=date(pb,"DMY")
format d %td
gen yr=year(d)

replace Bevölkerungswachstum_Projektjahr = Bevölkerungswachstum_2007 if inrange((Projektbeginn), mdy(01, 01, 2007), mdy(12, 31, 2007))
is equivalently
replace Bevölkerungswachstum_Projektjahr = Bevölkerungswachstum_2007 if year(Projektbeginn)==2007

If you have a bunch of these statements, consider merge-ing with a reference file. Updating for next year will be much easier.
Nick's explanation of the error you are getting is correct.
Best, Sergiy Radyakin

[Jay Rege]

destring

worked absolutely fine, the underlying problem was that some missing Variables where coded as

..