20/08/2011

Experiences from the JPBD slope analysis plugin project


Pengalaman dari projek JPBD slope analysis plugin

Projek R&D ini dilaksanakan awal 2011 dan melibatkan penyediaan JPBD slope analysis plugin untuk membangunkan satu plugin khas untuk QGIS bagi kedua-dua versi sistem operasi Windows and Ubuntu dengan tujuan menjalankan slope analysis. Perancangan jangkamasa panjang adalah agar plugin tersebut, jika berjaya, dapat dikongsi bersama semua pihakberkuasa perancang tempatan untuk membantu mereka memproses permohonan kebenaran merancang dikawasan bukit dan tanah tinggi. Plugin open source ini bermakna modul GIS tersebut yang boleh dipasang pada mana-mana komputer tanpa lesen dan akan menjimatkan hampir RM5,000-RM10,000 bagi setiap komputer dimana saja dipasang. Oleh kerana projek ini  merupakan projek unggul melibatkan perisian open source, kami serta perunding tidak dapat menjangka apa jua cabaran dan kesulitan yang boleh menimpa.

Apabila projek berakhir, ianya menonjolkan beberapa isu dalam pelaksanaan plugin yang mengubahkan arah tuju pembangunan plugin QGIS. Dari aspek positif, ianya telah membuktikan bahawa penyediaan plugin bagi QGIS atau mana-mana perisian open source dapat dicapai berbanding dengan perisian proprietary GIS atau GIS berlesen kerana source code tidak terkawal seperti GIS berlesen dan boleh dibuka untuk rujukan seterusnya customize, jika perlu. Selain dari itu, JPBD slope analysis plugin tidak dapat menghasilkan output seperti dirancang kerana pengkelasifikasi range default adalah mengikut equal classification. Bagaimanapun, ini tidak sesuai bagi JPBD yang memerlukan unequal classification. Apa yang tidak tersangka juga adalah pembangunan plugin tersebut tidak dapat dibuat kompatibil bersama versi QGIS baru kerana setiap versi QGIS terkini terdapat fail-fail library baru yang perlu dikupas dan disalinkan kedalam plugin. Jika fail-fail library tersebut tidak sesuai, kerja customization perlu dibuat keatas plugin, fail library, kedua-duanya atau pun melalui pembangunan interface baru agar plugin dan fail library dapat "bercakap". Semua ini pasti akan menambahkan kos  asal projek dan memandangkan kos customization bukannya murah, langkah diambil untuk menyelidik kebolehan QGIS untuk mencapai output yang disasarkan bergantung kepada pakej QGIS-GRASS dimana modul-modul open source GRASS GIS akan di import kedalam QGIS.

Ahkirnya langkah R&D berjaya menghasilkan output yang lebih tepat berbanding dengan JPBD slope analysis plugin kerana pengguna kini boleh menetapkan User Define Input masing-masing. Finding tersebut dijelaskan kepada pihak pengurusan dan keputusan dibuat supaya projek JPBD slope analysis plugin dihentikan akan tetapi Jabatan terus mendalami pakej QGIS-GRASS mudah-mudahan ianya dapat mendedahkan peluang-peluang lain dimana penggunaan pakej tersebut dapat dioptimakan bagi lain-lain analisis perancangan bandar. Itulah al kisahnya"The Rise and Fall of the JPBD slope analysis plugin".

Experiences from the JPBD slope analysis plugin project

This R&D project was implemented early 2011 and involved the preparation of the JPBD slope analysis plugin specifically for QGIS for both the Windows and Ubuntu version with the purpose of carrying out slope analysis. The long term planning, if it was successful was to share it with local planning authorities to assist them in processing planning applications in hilly and highland areas. Th  open source plugin meant that the QGIS module could be installed in any computer without licence and could save RM5,000-RM10,000 per computer. As this project represents the first involving open source software, we and the consultant did not anticipate the challenges and difficulties to come.


The the project ended, it highlighted several issues in the implementation of the plugin that changes the direction in the development of QGIS plugins. Froma apositive aspect, it had proven that the preparation of plugins for  QGIS or any open source softwares can be achieved compared to proprietary GIS because the source code is not protected like proprietary GIS and can be referred to or customized, if needed. Other than that, the JPBD slope analysis plugin did not produce the expected output as planned because the default classification range is based on equal classification.This made it compatible for JPBD use which requires otherwise. What was not anticipated in the development of the plugin was incompatible with newer QGIS version which contains new libraries that need to be found and copied into the plugin. If found to be incompatible, the plugin needs to be further customized to the libraries or both or through the interface so that plugin and libraries can "talk" to one another. All this involves additional cost over the original estimate and since customization is not cheap, a decision was made to GIS to obtain the required output that was targeted base on the QGIS-GRASS package where open source GRASS GIS modules can be imported into QGIS. 

In the end, the R&D suceeded in producing the expected output and with more accuracy than the JPBS slope analysis because the use can set his own User Define Inputs. This finding was made known to the management and a decision was made so that the JPBD slope analysis project was stopped but the the department still continue with the QGIS-GRASS package in the hope that it can open other opportunities where this package can be optimized for other town planning analysis. This is the story of  the Rise and Fall of the JPBD slope analysis plugin.

2 comments:

  1. You wrote: "because the source code is not protected like proprietary" ...

    Sir, open source software IS protected by its licence (GPL, AGPL, etc), the same way commercial software is protected by various End-user License Agreements.

    The only difference is that with open source software, you also have the right to modify these codes, publish it (or not, depending on which license) which you don't have in most commercial software.

    May I inquire what are the specific and unique requirements you have for slope analysis that is not met by presently available F/LOSS terrain analysis software?

    ReplyDelete
    Replies
    1. Thank you again for pointing that protection issue.

      Having ventured into GRASS modules, I believe a QGIS-GRASS package can easily fulfill a slope analysis. The problem is not with the module but my R&D section could not provide me with the necessary parameter values to input for "environmentally sensitive areas" which in my opinion is not my responsibility but theirs so I kicked the ball to their compound and it has been there ever since.

      Delete