Re: st: A precision problem

[Ronnie Babigumira <rb.glists@gmail.com>]

Thanks Maarten.

This is extremely helpful (and it is the first time I see the intutive reldif function)

Ronnie

Maarten buis wrote:
> What about:
> list houscode cinp_qty cinp_unpx cinp_totcost /// 
> if reldif(cinp_qty*cinp_unpx, cinp_totcost) > 1e-6
>
> Hope this helps,
> Maarten
>
> --- Ronnie Babigumira <rb.glists@gmail.com> wrote:
>
>
> > Dear List
> >
> > My setup is Stata 10, winxp
> >
> > I am "cleaning" some household data and I would like to identify
> > cases where the product of quantity (cinp_qtry) and 
> > price (cinp_unpx) is not equal to the total cost (cinp_totcost) as
> > entered in the data.
> >
> > The data look something like this
> >
> >      houscode   cinp_qty   cinp_unpx   cinp_totcost
> >            34          3          .6            1.8
> >            69          3          .6            1.8
> >            70          3          .6            1.8
> >            75          6          .6            3.6
> >            97          3          .6            1.8
> >           100          6          .6            3.6
> >           103          3           1             90
> >
> > My first take was
> >
> > - list houscode cinp_qty cinp_unpx cinp_totcost if cinp_totcost ! =
> > (cinp_qty * cinp_unpx) -
> >
> >      houscode   cinp_qty   cinp_u~x   cinp_t~t
> >             1          5         .6          3  <--------
> >            34          3         .6        1.8
> >            54          5         .6          3
> >            69          3         .6        1.8
> >            70          3         .6        1.8
> >            75          6         .6        3.6
> >            90          5         .6          3
> >
> >
> > When this caught the 3, I changed it to
> >
> > list houscode cinp_qty cinp_unpx cinp_totcost if cinp_totcost ! =
> > float(cinp_qty * cinp_unpx)
> >
> > This improved things a bit however, the 1.8's were still caught.
> >
> >      houscode   cinp_qty   cinp_u~x   cinp_t~t
> >            34          3         .6        1.8
> >            69          3         .6        1.8
> >            70          3         .6        1.8
> >            75          6         .6        3.6
> >            97          3         .6        1.8
> >           100          6         .6        3.6
> >           103          3          1         90
> >
> > I then decided to first generate a new variable which I called
> > pc_totcost computed as
> >
> > gen float pc_totcost = cinp_qty * cinp_unpx
> >
> > Then I issued
> >
> > list  househd houscode  cinp_qty  cinp_unpx cinp_totcost pc_totcost
> > if  ///
> > cinp_totcost !=  float(pc_totcost)
> >
> >
> >      houscode   cinp_qty   cinp_unpx   cinp_totcost   pc_totcost
> >            34          3          .6            1.8          1.8
> >            69          3          .6            1.8          1.8
> >            70          3          .6            1.8          1.8
> >            75          6          .6            3.6          3.6
> >            97          3          .6            1.8          1.8
> >           100          6          .6            3.6          3.6
> >           103          3           1             90            3
> > <----- this is the only "bug"
> >            70          3          .6            1.8          1.8
> >            70          3          .6            1.8          1.8
> >            97          3          .6            1.8          1.8
> >            97          3          .6            1.8          1.8
> >           100          6          .6            3.6          3.6
> >
> > The 1.8's and 3.6's are "ok" to me. How can I get Stata to ignore
> > them
> >
> > Ronnie
> > *
> > *   For searches and help try:
> > *   http://www.stata.com/support/faqs/res/findit.html
> > *   http://www.stata.com/support/statalist/faq
> > *   http://www.ats.ucla.edu/stat/stata/
>
> -----------------------------------------
> Maarten L. Buis
> Department of Social Research Methodology
> Vrije Universiteit Amsterdam
> Boelelaan 1081
> 1081 HV Amsterdam
> The Netherlands
>
> visiting address:
> Buitenveldertselaan 3 (Metropolitan), room Z434
>
> +31 20 5986715
>
> http://home.fsw.vu.nl/m.buis/
> -----------------------------------------
>
>
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> *
> *   For searches and help try:
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*
*   For searches and help try:
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