26/02/2013

* Training: Forestry Department get trained in QGIS, 25-26.2.2013




Training: Forestry Department get trained in QGIS, 25-26.2.2013

Request for QGIS training from public agencies come again and the first to be trained this year is the Forestry Department held at their headquarters in Kuala Lumpur. They explained how they are keenly looking at QGIS to overcome their dwindling financial resources and are happy to note that it can retrieve their geospatial files kept in .shp format. They will give themselves some time to be more familiar with QGIS then hope to extend its use nationwide to their state departments.

Peserta

Che Razali Che Adnan
Mudah dan cepat difahami, mempunyai kelebihan dalam menggunakan Google Maps dsb.nya dan mengurangkan kos ssoftware

Mod. Shahril Yusop
QGIS ni agak baru bagi saya maka kursus yang ditetapkan oleh Urusetia agak singkat untuk difahamai dalam masa terdekat lagi peggunaan yang selalu munkin boleh memahirkannya.

Supian Ismail
Adalah baik dipelbagaikan/kemahiran penggunaan QGIS disemua Jabatan. Ia memerlukan pendedahan yang lebih mendalam untuk menguasai sepenuhnya terutama untuk kerja editor. Memerlukan masa yang lebih lama kerana kurang tenaga pengajar.

Wahab Mohd Zin
Perisian ini baik kepada semua agensi kerajaan. Ianya memerlukan masa yang panjang untu memahai dengan lebih mendalam. QGIS sangat baik.

Mohamad Hazri
User-friendly, sangat mudah difahami

Salmiah Osman
Mudah difahami, menarik, ikon yang menarik sebab berwarna warni

Wan Ahmad Zakry Abd. Halim
QGIS ini bagus, percuma, berwarna warni dan ceria, mudah faham tapi kena belajar lebih lagi untuk mahir, mesra pengguna

Noorizah Mat Ghani
Software sangat bagus dan bertambah bagus kerana ianya percuma. Mudah difahami. Perlu berkursus lebih detail lagi memahami ikon-ikon apa yang terdapat dalam QGIS.

Noorazila
Software ini bagus dan user-friendly. Interface yang menarik dan mudah difahami

19/02/2013

Unknown map projections?

Find your particular file under "Choose File"
Select "Convert" and see the results. Cool eh?
Here, it seems to limit .prj file to 4kb
Map projection tidak diketahui?

Apa? Pada mulanya, bagaimana perkara ni boleh terjadi? Takkan tak tahu sebelum berjalan kena belajar merangkak? Tak pa, Abbas ada. Hai, kalau saya tak da macam mana? :-D Saya kaki sibuk sini sana dan terjumpa sesuatu yang mungkin, saya kata 'mungkin' boleh membantu. Sila kesini dan cuba try. Saya mencuba walaupun menggunakan sampel yang mempunyai projection tapi puashati dengan hasilnya. Kalau ianya dapat membantu, kita semua perlu ucapkan ribuan terima kasih kepada OpenGeo. Ringkas tapi berkesan. Benda ni masih baru untuk saya belum sempat godek-godek lagi.

Unknown map projections?

What? How did you get into this trouble in the first place? Don't you know before you walk, you must first learn to crawl. Never mind, Abbas is here. What would you do without me? :-D Well, cheapskate busy bee me found something that may, I said 'may' help you. Jump over to here and give it a try. I gave it a try though using a known projection was impressed with the results. If it does work out, we must thank OpenGeo. It's so simple yet effective. It's so new for me, I have yet time to comment on it.

15/02/2013

PgAdminIII-PostGIS connection

Yes, I got in!
See, I created a test database and test table.
Sambungan PgAdminIII-PostGIS

Pada bulan lepas, setelah melabur komputer baru lalu dipertingkatkan status komputer lama ke tahap server, saya berjaya memasang PostgreSQL-PostGIS tanpa bantuan. Hari ni merupakan hari bertuah   kerana ini kali pertama saya berjaya menyambung klien-server. Selepas mengodek-godek PgAdmin III,saya berjaya menymbungnya dengan PostGIS dan mewujudkan pelbagai jenis pengguna, pangkalan data dan jadual. Pada langkah kedua, semalam, saya juga berjaya menyambung QGIS dengan PostGIS dengan setup yang sama di pejabat menggunakan komputer-server yang betul tapi belum lagi dirumah kerana terlalu lewat. Bagaimana pun, saya amat gembira dengan hasil cubaan ni.

PgAdminIII-PostGIS connection

Last month, having invested a new computer then upgrading my old computer to the status of a server, I successfully installed PostgreSQL-PostGIS on my own. Today is a great day for me because it is the first time I managed to secure a client-server connection. After tinkering with PgAdmin III, I managed to connect it to PostGIS then created different types of users, a database and table. In the next step, yesterday, I managed to link QGIS to PostGIS at the office equivalent setup but with a real client-server hardware though I haven't managed it yet at home because it's too late. Still, I'm very happy with myself.

Update:

I haven't got much further than this link for further reference.

07/02/2013

Cleaning data with field calculator


Membersihkan data dengan field calculator

Berapakah cara adakah untuk membersihkan data? I sendiri tak tahu dan menyerahkannya kepada pengguna GIS yang lebih mahir tapi ini saya tahu: terdapatnya data spatial dan data bukan spatial. Semasa mengodek-godek field calculator untuk menghitungkan keluasan kawasan lot, saya menyedari pada kawasan kajian, terdapatnya keluasan kawasan bagi 2 lot jauh lari. Bagaimana perkara ini boleh jadi? Selepas meneliti salah satu kesilapan, kemungkinannya diakibatkan pertindihan polygon lalu dihitung 2 kali. Hanya selepas kesilapan tersebut diperbaiki, output menjadi lebih realistik. Nampaknya, ini merupakan satu cara untuk menyemak kualiti data.

Cleaning data with field calculator

How many ways are there to clean data? I won't answer that but leave it to the more experience GIS user simply because I do not know but this I know: that are spatial and non-spatial errors. While tinkering around with the field calculator to obtain the acreage of land plots, I noticed from my case study, the acreage for 2 lots ran wild. How could that be? Upon checking one of them, I soon realized it had overlapping polygons so the field calculator double-counted itself and only after   topology error was rectified did the field calculator provide a more realistic output. This looks like one way of checking the quality of the data.


06/02/2013

* Malaysian townplan publishes another of my article


Malaysian townplan menerbitkan salah satu artikel saya

Disediakan tahun lalu, "Fundamental issues affecting town and country planning in Malaysia" merupakan salah satu artikel yang saya berjaya masukkan dalam Malaysian townplan,  jurnal jabatan, boleh tahan bagi seorang yang tidak biasa menulis :-D. Saya cuma hendak memaklumkan kepada mereka dari dunia perancang bandar agar jangan terima bulat-bulat sesuatu perisian GIS dan menganggap ianya boleh menghasilkan apa jua saja serta jangan percaya sangat vendor perisian GIS ataupun mereka yang telah lama menggunakan perisian GIS bahawa mereka tahu semua, ini yang saya alami.
Malaysian townplan publishes another of my article

Written last year, "Fundamental issues affecting town and country planning in Malaysia" represents another of my article that eventually got into the Malaysian townplan, my department's journal, not bad for one who is not does not often write :-D. I just wanted to inform people from my town planning world not to take a GIS software for granted and assume it can do everything and not to be taken in by GIS software vendors or people such as those who have been using a GIS software for umpteen years that they know everything as I found along the way.

04/02/2013

Contour Plugin review

In Windows QGIS, Contour plugin worked like a breeze...



Except for this funny output
Which did not make much difference to the southern portion contours
Contour plugin homepage set 3 prerequisite modules...
In Ubuntu QGIS, Numpy was installed...
So was Matplotlib ...
And was Shapely ...
Yet disappointing error message still crops up. Rats!
Ujilari Contour Plugin

Pertama, nampaknya versi Windows berbanding dengan versi Ubuntu lebih mudah untuk pasang. Versi Ubuntu pasti akan mendapat kritik novis yang cuma hendak siapkan kerja secepat mungkin. Nasib baik komputer dwi OS saya mengatasai masalah ini kerana sekiranya jalan kiri tersekat masih ada jalan alternatif. Saya mula dengan mengekspoitasi Google Map dan memilih kawasan Genting Highland di Pahang sebagai kawasan kajian. Diwujudkan lapisan elevation, ditindihkan Google Physical lalu disediakan beberapa titik elevation berasaskan garis selar dibawah. Seterusnya, dikonfigur Contour plugin lalu dioperasinya. Hasil ujilari adalah serentak tetapi saya kurang puashati kerana output tidak mencerminkan kawasan two bukit yang saya wujudkan. Terdapat satu kawasan melebihi 1600m yang tidak sempurna. Selepas mengeluarkan salah dari satu bukit, output selar masih tidak sempurna. Sama ada plugin perlu dimantapkan lagi atau saya yang perlu lebih mahir lagi dengan plugin tersebut kurang pasti, bagaimana pun, saya kagum penyediaan selar amat mudah dan kebolehan menghasilkan bilangan selar mengikut keperluan pengguna dengan mudah perlu dipuji.

Contour Plugin review

Well, for one, the Windows as against the Ubuntu version installation was a surprise and went like a breeze. The Ubuntu version would put off the novice who just wants to get the job done. Fortunately for me, my dual boot computer solves this problem and if the left upper cut doesn't, the right uppercut will. My trial involved exploiting Google Map and my study area was the famous Genting Highland resort area in Pahang. I created a simple elevation layer, overlaid it over Google Physical and proceeded to create a few elevation points based on the contour line underneath. Then I configured the Contour plugin and ran it. The result was immediate but I was surprised and a bit disappointed the output  did not reflect the two hill tops I created. A certain portion above 1600m did a cheeky shortcut. I decided to delete the small hilltop and the contour adjusted itself for the second output but was still not complete. Room for improvement here or room for further trials for me to carry out, still, I was impressed it was so easy to create and customize the number of contour lines to my choice.

03/02/2013

Check Geometry Validity in Geometry Tools





Check Geometry Validity in Geometry Tools

Ensuring the quality of the geospatial data is excellent is critical before going into spatial analysis so you can understand how excited I was when I first saw this module under Vector/Geometry Tools/Check Geometry Validity. I said wow! but at the end of the day, I do not know what to say about it whether I am disappointed or is it because I am ignorant in using it. I successfully managed to transform the identified geometry errors into a spatial form using csv and the Delimited Text Layer tool but after zooming in one of the  identified sites as shown above, it was not about over or undershoots, gaps or overlaps so I do not know what type of geometry error the plugin saw in it, in fact most of the other identified geometry errors look the same. I am lost. Any advice?

How to install Contour plugin?


How to install Contour plugin?

For the time being, my interest  was installing Lionel Roubeyrie's Contour plugin in Ubuntu mode but I was first greeted by a prerequisite because matplotlib module was missing. A search on the Internet let me to try out purely the matplotlib module installation script which solved that but was greeted by another missing module... shapely.geometry. I hate that and who knows what other modules will be missing. Some search later, I eventually ended with the following scripts which installed the Contour plugin and after activated under Fetch Plugin, it appeared in the menu bar:

wget http://python-distribute.org/distribute_setup.py
sudo python distribute_setup.py
wget https://raw.github.com/pypa/pip/master/contrib/get-pip.py
sudo python get-pip.py

# to install from git source
sudo apt-get update
sudo apt-get install git

sudo apt-get install python-dev
sudo pip install numpy

sudo pip install cython
sudo apt-get install libproj-dev

# install geos 
sudo apt-add-repository ppa:sharpie/for-science
sudo apt-get update
sudo apt-get install libgeos-dev

sudo pip install shapely
sudo apt-get install python-scipy
sudo pip install pyshp

sudo apt-get install python-imaging

sudo apt-get build-dep matplotlib
wget https://github.com/downloads/matplotlib/matplotlib/matplotlib-1.2.0rc2.tar.gz
tar xzf matplotlib-1.2.0rc2.tar.gz
cd matplotlib-1.2.0rc2
sudo python setup.py install

ref>https://github.com/SciTools/cartopy/issues/46

At least, I got the Contour plugin in the menu bar, I have yet to try it out because I have to go out. (Family quality time is also important as QGIS)

Update:

Contour Plugin under Windows mode installed without any hiccup so I decided to give it a try. I got some unexpected results

01/02/2013

* A Gentle Introduction to GIS


A Gentle Introduction to GIS

Mereka yang telah maju dalam GIS mungkin tak akan pandang buku ini tetapi saya telah membaca dan menghargainya kerana seperti tajuknya kata, adalah pengenalan ringkas kepada subjek yang teknikal dan pada pandangan saya adalah lebih sukar difahami berbanding dengan isu yang mendalam seperti analisis spatial. Disediakan oleh Tim Sutton, Otto Dassau dan Marcelle Sutton untuk the Office in the Primer, Eastern Cape, South Africa, mereka telah memberi kebenaran untuk terbitan ini disalin, edar dan juga ubahsuai (My!), elok kita ucapkan ribuan terima kasih kerana nak mencari rujukan yang menggunakan Quantum GIS sebagai alat GIS bukannya senang. Kini ianya oleh dibaca di Internet disini

A Gentle Introduction to GIS

Those who have advanced into GIS may not give a second look at this book but I have read and personally like it very much because like what it says, it is a gentle introduction on a technical subject which to me is a bigger hurdle than having advanced into GIS and going into spatial analysis issues. Prepared by none other than Tim Sutton, Otto Dassau and Marcelle Sutton for the Office in the Primer, Eastern Cape, South Africa, they gave permission for it to be copied, distribute and even modified (My!)  so we must say a big thank you to them because references that use Quantum GIS as the GIS tool are not many which is actually what we like don't we? Now you can read it on the web here