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Re: st: RE: using encode to order string distances
From
Nick Cox <[email protected]>
To
[email protected]
Subject
Re: st: RE: using encode to order string distances
Date
Tue, 25 Oct 2011 09:40:38 +0100
An alternative is to start by using regex (regular expression) functions.
-moss- (SSC) is a convenience tool wrapped around Stata's regex
technology. Its use here is perhaps overkill:
. l
+-------+
| var1 |
|-------|
1. | 0-9 |
2. | 10-19 |
3. | 20-29 |
4. | 30+ |
+-------+
. moss var1, match("([0-9]+)") regex
. l
+----------------------------------------------------+
| var1 _count _match1 _pos1 _match2 _pos2 |
|----------------------------------------------------|
1. | 0-9 2 0 1 9 3 |
2. | 10-19 2 10 1 19 4 |
3. | 20-29 2 20 1 29 4 |
4. | 30+ 1 30 1 . |
+----------------------------------------------------+
Nick
On Mon, Oct 24, 2011 at 6:28 PM, Nick Cox <[email protected]> wrote:
> You need to parse your strings and order on the numeric equivalent of the lower value. That will be sufficient because the upper values increase too, except that the open upper limit is implicit.
>
> Here is one way to do it.
>
> Suppose -sdist- is string variable with distances.
>
> gen pos = max(strpos(sdist, "-"), strpos(sdist, "+"))
>
> We look for "-" or "+".
>
> gen n1 = real(substr(sdist, 1, pos-1))
> egen group = group(n1)
> labmask group, values(sdist)
>
> where -search labmask- will point to download locations.
>
> Nick
> [email protected]
>
> Tim Evans
>
> I have distances stored in strings like:
>
> 0-9
> 10-19
> 20-29
> 30-39
>
>
> up to
> 90-99
> 100+
>
> I want to encode these to keep the current values as labels and replace the numbers behind them as 1-12.
>
> When I encode and generate a new variable I end up with 100+ as the 3rd value rather than the 12th value.
>
> How can I force encode to make sure 100+ is the 12th and not the 3rd value.
>
> I'm using
>
> encode nearestcentre, generate(NRCENT)
>
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