Re: st: Advice on content of a do file

[Sergiy Radyakin <serjradyakin@gmail.com>]

the code works just fine, as in the following example:
sysuse auto,clear
matrix UTILS=(-0.001,0.101,0.191,0.222\/*
> */-0.024,0.096,0.189,0.228\/*
> */0.006, 0.084, 0.156, 0.188\/*
> */0.021, 0.091, 0.159, 0.181\ /*
> */ -0.003, 0.069, 0.154, 0.181)

gen stability=_n
gen sta_index=UTILS[1,stability[_n]]

However it relies on stability being a numeric variable. The error
message 509 is consistent with stability being a string variable. You
may want to investigate why this happened, and if it can be
-destring-'ed or otherwise converted to numeric codes.

Note, that Stas is right that there are other ways to write the same.
I would prefer here:

generate sta_index = real(word("-0.001 0.101 0.191 0.222",stability))

Best, Sergiy


On Fri, Jul 26, 2013 at 11:16 AM, Stas Kolenikov <skolenik@gmail.com> wrote:
> This is a TERRIBLE way to write code. It relies too heavily on having
> things specified exactly as the developer thought, rather than
> adapting to the users' data. Instead, it should have been written as
>
> gen sta_index = .
> replace sta_index = -0.001 if stability == 1
> replace sta_index = 0.101 if stability == 2
> replace sta_index = 0.191 if stability == 3
> replace sta_index = 0.222 if stability == 4
>
> etc.
>
> It looks like the developers thought their code would work, but never
> tried it. And it did not, in practice.
>
>
> -- Stas Kolenikov, PhD, PStat (ASA, SSC)
> -- Senior Survey Statistician, Abt SRBI
> -- Opinions stated in this email are mine only, and do not reflect the
> position of my employer
> -- http://stas.kolenikov.name
>
>
>
> On Fri, Jul 26, 2013 at 1:12 AM, Peter King <kingsocres@gmail.com> wrote:
>> Hi All,
>>
>> I'm preparing to analyse survey responses to the ICECAP-A questionnaire. The
>> ICECAP-A developers have provided code to substitute into a Stata do file to
>> allow the calculation of values or tariffs for each respondent.
>>
>> The code is as follows:
>>
>> matrix UTILS=(-0.001,0.101,0.191,0.222\/*
>>
>> */-0.024,0.096,0.189,0.228\/*
>>
>> */0.006, 0.084, 0.156, 0.188\/*
>>
>> */0.021, 0.091, 0.159, 0.181\ /*
>>
>> */ -0.003, 0.069, 0.154, 0.181)
>>
>> gen sta_index=UTILS[1,stability[_n]]
>>
>> gen att_index=UTILS[2,attachment[_n]]
>>
>> gen aut_index=UTILS[3,autonomy[_n]]
>>
>> gen ach_index=UTILS[4,achievement[_n]]
>>
>> gen enj_index=UTILS[5,enjoyment[_n]]
>>
>> gen tariff=sta_index+att_index+aut_index+ach_index+enj_index
>>
>>
>> I have formatted my data as specified below:
>>
>> "This code, when substituted into a Stata do file, will allow calculation of
>> ICECAP-A tariffs for each respondent in a study, based on their answers to
>> the five classification questions. Statistical analyses can then be
>> conducted on these tariffs. Indeed they can be conducted on the five index
>> values also, to ascertain sensitivity of these to differences in factors.
>>
>>
>> "Data should be set up with one study participant per row. As specified on
>> the ICECAP-A questionnaire, coding should be such that the 'top' level (full
>> capability for an attribute) should take the value '4', down to the bottom
>> level (no capability) which should take the value '1'. NB this coding is the
>> opposite of that used in instruments such as the EQ-5D (where 1 is top
>> level). The five variables, containing a respondent's five ICECAP-A
>> responses should be named stability, attachment, autonomy, achievement,
>> enjoyment."
>>
>> When I run the do file with the specified content I get the following
>> reply/output:
>>
>> . do "C:\Documents and Settings\User\My Documents\FCSPRU Files\Current
>> projects\BIS 2006\Surve
>>> ys\Postal survey\Wave 2 2012\ICECAP Tariff.do"
>>
>> . matrix UTILS=(-0.001,0.101,0.191,0.222\/*
>>> */-0.024,0.096,0.189,0.228\/*
>>> */0.006, 0.084, 0.156, 0.188\/*
>>> */0.021, 0.091, 0.159, 0.181\ /*
>>> */ -0.003, 0.069, 0.154, 0.181)
>>
>> . gen sta_index=UTILS[1,stability[_n]]
>> matrix operators that return matrices not allowed in this context
>> r(509);
>>
>> end of do-file
>>
>> r(509);
>>
>> .
>> I am new to using do files and wonder whether I should be including other
>> information in the do file?  Or is something else wrong in the code?
>>
>> Any suggestions from more experienced users will be greatlt appreciated.
>>
>>
>> Many thanks,
>>
>> Peter King
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