10/09/2012

Fooling around with hills

Using polygons to make contours
Transforming polygons into lines
Extracting nodes from lines
Trying out a Delaunay  triangulation
Godek-godek sekitar bukit

Sudah amat lama sejak saya menjalankan analisis kecerunan yang dibuat semasa kursus sarjana, oleh tu, minta ampun sekiranya lupa teknik berkaitan, dah tua. Akan tetapi, bergantung kepada apa yang   masih diingati, saya aktifkan Google Physical dan cuba mewujudkan selar menggunakan kaedah polygon kerana tak perlu memikir macam mana nak sambungkan titik permulaan dan titik hujung. Saya  mula cari jalan mudah dan jumpanya bawah Geometry tools dimana boleh ditransformasikan  polygon ke garis, lalu mencuba dan berjaya! Attribute table juga cemas ditransformasi. Dah mula berani, terus saya mencuba wujudkan node dari garisan (contour) menggunapakai Geometry tools dan berjaya sekali lagi. Yahoo! Saya teruskan dan cuba menjalankan Delaunay triangulation dan berjaya menghasilkan output berkaitan. Akhirnya, saya nak nak terus interpolate node tetapi dah lupa macam mana nak buat. Cis! Pasti saya ni dah tua tapi kini sedang membaca cara-nak-buat disini.

Fooling around with hills

It has been a long, long time since I toyed around with slope analysis when I did my Masters of Science course so excuse me if I forgot a lot about the techniques required, I'm getting long in the tooth. But relying on what I remembered I activated Google Physical and tried to create contour lines using the polygon way because it seemed simple than having to think how to tie the end to the starting point. I looked at ways on how to cheat then found out under Geometry tools, it is possible to transform polygons to lines so I gave it a try and yes! It worked! Even the attribute table was correctly transformed. Getting braver, I tried to extract nodes from the (contour) lines using the Geometry tools and it worked. Yahoo! Just for the heck of it, I gave the Delaunay triangulation a try, it successfully produced the appropriate output. Lastly, I wanted to proceed to interpolate the nodes but forgot how to go about it. Rats! No doubt about it, I'm getting old but I'm reading how-to here. 

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