[gdal-dev] Re: Slope in gdaldem

[Joaquim Luis]

>
>     float pafLocalMin = afWin[0];
>      float pafLocalMax = afWin[0];
>
>     for ( int k = 1; k < 9; k++)
>     {
>         if (afWin[k] < pafLocalMin)
>         {
>             pafLocalMin=afWin[k];
>         }
>
>         if (afWin[k] > pafLocalMax)
>         {
>             pafLocalMax=afWin[k];
>         }
>
>     }
>

>     key = afWin[4] - pafLocalMin;
>
>     if (key < 0)
>      {
>         key = afWin[4] - pafLocalMax;
>      }
>

Stephen

'key' can never be negative because pafLocalMin is computed from 'afWin' 
alone. The min val it can have is 0, when the minimum value is the 
central node itself.

Joaquim