Re: st: loop until "0 real changes made"

[Robert Picard <picard@netbox.com>]

Here's a more complete example of how to continue making substitutions
until there are no more changes. I'm with Nick on using -clonevar-
when making an exact copy of a variable, it is faster than -generate-.
Also, avoid -regexr()- in Stata 13, it's slow as molasses.

* --------------- begin example ---------------------------
clear
set obs 100000

gen AD1 = string(uniform(),"%21x")
gen AD2 = string(uniform(),"%21x")
list in 1/5

foreach v of var AD* {
	local more 1
	while `more' {
		clonevar stemp = `v'
		replace `v' = subinstr(`v',"0X-","X-",.)
		count if `v' != stemp
		local more = r(N)
		drop stemp
	}
}
list in 1/5
* --------------- end example -----------------------------


On Mon, Jul 29, 2013 at 12:34 PM, Sergiy Radyakin
<serjradyakin@gmail.com> wrote:
> Nick's solution with two variables is the most generic approach that
> is useful in situations where it is difficult to predict if any
> changes are going to happen as a result of your code. It certainly is
> going to work here as well (I would only use a tempvar instead of AD2
> and generate instead of clonevar).
>
> However, why would you do this recoding to non-Turkish characters?
> Stata works with Turkish characters like with any other for which a
> corresponding ANSI page is available and proper font is installed:
>
> http://radyakin.org/statalist/2013072901/turkish.png
> http://radyakin.org/statalist/2013072901/turkish.do
>
> The ANSI page for Turkish is 1254. And I would try e.g.:
> replace `v'=regexr(`v', "`=char(196)'+`=char(158)'","`=char(208)'")
> instead of
> replace `v'=regexr(`v', "`=char(196)'+`=char(158)'","G")
>
>
> Best, Sergiy Radyakin
>
> On Mon, Jul 29, 2013 at 10:06 AM, Nick Cox <njcoxstata@gmail.com> wrote:
>> Plus the "+" if needed.
>> Nick
>> njcoxstata@gmail.com
>>
>>
>> On 29 July 2013 15:05, Nick Cox <njcoxstata@gmail.com> wrote:
>>> One answer is not to use regular expressions here at all. Use
>>> -subinstr()- with statements like
>>>
>>> replace `v' = subinstr(`v', "`=char(195)'`=char(135)'","C", .)
>>>
>>> Another answer is to set up a count of changes and stop when you hit zero.
>>>
>>> clonevar AD2 = AD
>>>
>>> foreach v of var AD {
>>>            replace AD2 = AD
>>>            <work with AD>
>>>            count if AD2 != AD
>>>            if r(N) == 0 continue, break
>>> }
>>>
>>> Nick
>>> njcoxstata@gmail.com
>>>
>>> On 29 July 2013 14:48, Haluk Vahaboglu <vahabo@hotmail.com> wrote:
>>>
>>>> I am using Stata 12.1 for Linux-64 bit and dealing with Turkish characters in string variables. I convert these Turkish characters (ı, ş, ü etc) to readable equivalents (i, s, u etc). Doing this with the code below:
>>>>
>>>> foreach v of var AD {
>>>>            replace `v'=regexr(`v', "`=char(195)'+`=char(135)'","C")
>>>>            replace `v'=regexr(`v', "`=char(196)'+`=char(176)'","I")
>>>>            replace `v'=regexr(`v', "`=char(195)'+`=char(167)'","c")
>>>>            replace `v'=regexr(`v', "`=char(195)'+`=char(182)'","o")
>>>>            replace `v'=regexr(`v', "`=char(196)'+`=char(177)'","i")
>>>>            replace `v'=regexr(`v', "`=char(196)'+`=char(158)'","G")
>>>>            replace `v'=regexr(`v', "`=char(196)'+`=char(159)'","g")
>>>>            replace `v'=regexr(`v', "`=char(195)'+`=char(156)'","U")
>>>>           replace `v'=regexr(`v', "`=char(195)'+`=char(188)'","u")
>>>>           replace `v'=regexr(`v', "`=char(197)'+`=char(158)'","S")
>>>>           replace `v'=regexr(`v', "`=char(195)'+`=char(150)'","O")
>>>>           replace `v'=regexr(`v', "`=char(197)'+`=char(159)'","s")
>>>> }
>>>>
>>>> However, this code cannot accomplish the conversion at the first time. Therefore, I have to do it 5 to 10 times to get a (0 real changes made) message.
>>>> My question is: can I make this loop run automatically until I get the (0 real changes made) message which indicates that all characters are converted.
>>
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>
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