This is great work, thanks for posting! Looking forward to the second blog
post.
On Mon, Aug 28, 2017 at 11:14 AM, Martin Desruisseaux <
martin.desruisse...@geomatys.com> wrote:
> Hello all
>
> In August 17th 2017, we presented an introduction to Apache Spatial
> Information System (SIS) in the Free and Open Source Software for
> Geospatial (FOSS4G) conference. Discussions about performance and
> accuracy were planed, but skipped because of lack of time. We put the
> intended content in a series of 2 blog posts. The first post, about
> performance, is available at [1]. The key findings are:
>
> * Proj.4 is generally faster than Apache SIS on Java 8. The identified
> cause is the cost of trigonometric functions.
> * Some (but not all) trigonometric functions are much faster in Java
> 9, but we have not yet benchmarked SIS on Java 9.
> * Despite the above, Apache SIS is sometime faster than Proj.4 (400
> times faster in an extreme case). This can be explained by
> mathematical work done in SIS.
> * Numerical results are in close agreement for map projections, but
> can differ by 1 or 2 metres for datum shifts. This is because of
> different ways to use the EPSG geodetic dataset ("early-binding"
> versus "late-binding" approaches).
>
> More details are given at [1]. A second blog focussed on the accuracy
> topic will be posted later.
>
> Martin
>
> [1] https://www.geomatys.com/wordpress/index.php/2017/08/
> 28/english-proj-4-versus-apache-sis-a-performance-comparison/?lang=en
>
>
>
