[Numpy-discussion] searchsorted bug

[Charles R Harris]

On Jan 31, 2008 10:49 AM, James Philbin <philbinj at gmail.com> wrote:

> Well, i've digged around in the source code and here is a patch which
> makes it work for the case I wanted:
>
> --- multiarraymodule.c.old      2008-01-31 17:42:32.000000000 +0000
> +++ multiarraymodule.c  2008-01-31 17:43:43.000000000 +0000
> @@ -2967,7 +2967,10 @@
>     char *parr = arr->data;
>     char *pkey = key->data;
>     intp *pret = (intp *)ret->data;
> -    int elsize = arr->descr->elsize;
> +
> +    int elsize1 = arr->descr->elsize;
> +    int elsize2 = key->descr->elsize;
> +
>     intp i;
>
>     for(i = 0; i < nkeys; ++i) {
> @@ -2975,14 +2978,14 @@
>         intp imax = nelts;
>         while (imin < imax) {
>             intp imid = imin + ((imax - imin) >> 2);
> -            if (compare(parr + elsize*imid, pkey, key) < 0)
> +            if (compare(parr + elsize1*imid, pkey, key) < 0)
>                 imin = imid + 1;
>             else
>                 imax = imid;
>         }
>         *pret = imin;
>         pret += 1;
> -        pkey += elsize;
> +        pkey += elsize2;
>     }
>  }
>

But is that safe? You have changed the stepping to adjust for the element
size, but there is no guarantee that the comparison works.

Chuck
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