Updates from July, 2008 Toggle Comment Threads | Keyboard Shortcuts

  • CG 6:53 pm on July 31, 2008 Permalink | Reply
    Tags: edge, , , vertex   

    Generating graph for grid map 

    Vertex list and edge list have been generated and these are graph representations for correlated maps.

    n = 4

    n = 10

    n = 20

    Next to do: generating more attributes for the graph (different colors, boldness, numbers, for indicating occupancy status)

    • Budi Rahardjo 6:59 pm on July 31, 2008 Permalink | Reply

      wow. beautiful graphs!

      next would be (1) different visual representation for node that is occupied; (2) indicator representing the occupancy value; (3) different representation for edges that are not available for traversing; (4) current robot’s location; (5) sequence of graphs as the robot travels; (6) …

      that’s too much already …

    • soni 7:03 pm on July 31, 2008 Permalink | Reply

      how can you generate the graph?
      i mean, the way you did that.
      it is automatic, isn’t it?
      do we just put the number of vertex, and the graph generated automatically?

    • chikaradirghsa 7:10 pm on July 31, 2008 Permalink | Reply

      @BR: keep us in track with the to do list! show us directions! please!!! 😀

      @soni: yes, by changing the n value (suppose the grid map is a 4×4 map then n = 4) then the corresponding graph will be generated automatically.

    • soni 7:23 pm on July 31, 2008 Permalink | Reply


      w o w !


    • waskita 5:37 pm on August 1, 2008 Permalink | Reply

      I miss something here. What’s the purpose of the graphs ?

    • chikaradirghsa 8:30 pm on August 1, 2008 Permalink | Reply

      @waskita: for representing grid maps and path

    • waskita 8:31 pm on October 14, 2008 Permalink | Reply

      how much has the grid map go so far ?

    • chikaradirghsa 9:43 pm on October 14, 2008 Permalink | Reply

      @waskita: going nowhere 😉
      now i’m back doing crypto and leaving those grid maps for a while 😀

  • CG 9:00 pm on July 29, 2008 Permalink | Reply
    Tags: dot, ,   

    Got some things done 

    Well, the framework is finally ready. And Graphviz worked just fine, it gave nice visualizations of our .dot files. Lovely!

    Next to do is modifying and optimizing the path planning module. And of course designing the best algorithm for navigation (Master Shifu has a million ideas in his head already.)

    There are also some progress for my quals prep. Have got approval for the title and also have got some corrections for the proposal and presentation slides. Good.

    Quite happy and progressing day 😉

  • CG 4:45 am on July 29, 2008 Permalink | Reply
    Tags: DOT language, graph visualization,   

    Graph representation 

    Map representation is done. Now creating path-planning on the map. I’m still doing some enhancements on the previous code while the robotics guy is working on the path-planning strategy. Master Shifu said that we need some graph representation to give us better visualization. He recommends Graphviz . I have succesfully downloaded and installed it, but don’t have any idea how to use it so let’s leave it to the Master to find out how to use it and explain what DOT language is. 😉

  • CG 5:45 pm on July 26, 2008 Permalink | Reply  

    Switching subject of research? 

    Oh well, meanwhile I’m learning about these heavy stuff about robotics and its navigation coding, my research fellow starts to post and learn about crypto.

    Hei! Are we going to switch?

    • soni 6:25 pm on July 26, 2008 Permalink | Reply

      we’re not going to switch.
      we usually call it ‘pabaliut’, hahahahahaha.

    • chikaradirghsa 6:29 pm on July 26, 2008 Permalink | Reply

      and, we are cursed to live like this together forever???
      aaaaaaa scarrrrrrryyyyyy!!!

    • soni 6:51 pm on July 26, 2008 Permalink | Reply

      jangan takut.
      terimalah semuanya dengan ikhlas dan lapang dada, gyahahahaha.

    • chikaradirghsa 10:56 pm on July 26, 2008 Permalink | Reply

      kenapa dadanya musti lapang, emangnya mau main futsal?

    • soni 4:49 pm on July 28, 2008 Permalink | Reply

      bukan. mau dipake jadi lingkungan pengujian robot.

    • chikaradirghsa 9:02 pm on July 28, 2008 Permalink | Reply

      ya lah. asal bukan dada gue.

      mau dada lu atau dada rosada, terserah 😛

  • CG 6:52 pm on July 24, 2008 Permalink | Reply

    More updates, more deadlines… 

    Experiencing this symptom while still working on the codes, yesterday I got a message from my academic advisor saying that he wants me to get ready and do the quals on August! And my partner asked me to revise our research proposal which has to be done by mid-August.

    Hoping that I can juggle my tasks very well, without “dropping” anything!

    • soni 5:33 pm on July 28, 2008 Permalink | Reply

      without “dropping” anything?
      ga mungkin.
      itu udah naluri manusia, setiap pagi 😀

    • chikaradirghsa 9:01 pm on July 28, 2008 Permalink | Reply

      ga sopan!

  • CG 7:09 pm on July 23, 2008 Permalink | Reply
    Tags: ,   

    vertex_occupancy_t blallaglalalalahaia… 

    Creating tag types for properties :

    enum vertex_occupancy_t { vertex_occupancy };
    namespace boost {
    BOOST_INSTALL_PROPERTY(vertex, occupancy);}

    Use new property tag in the definition of properties:

    typedef property<vertex_occupancy_t, int> Occ;

    Create a typedef for the Graph type, bidirectionalS means undirected graph:

    typedef adjacency_list<vecS, vecS, bidirectionalS, Occ> GraphCG;

    Get the property map for vertex indices:

    typedef property_map<GraphCG, vertex_occupancy_t>::type StatusVertex;

    Declaring the graph object:

    GraphCG g(num_vertices);
    StatusVertex status = get(vertex_occupancy, g);

    Adding the edges to the graph object:

    for (int i = 0; i < num_edges; ++i)
       add_edge(edge_array[i].first, edge_array[i].second, g);

    The property maps for these properties can be obtained from the graph via the get(Property, g) function:

    property_map<GraphCG, vertex_occupancy_t>::type occupancy
    = get(vertex_occupancy, g);

    Setting occupancy for vertex:

    put(occupancy, 3, 9);
    put(occupancy, 9, 3);
    occupancy[2] = 7; // you can use operator[] too

    Accesing the vertex set:

    typedef graph_traits<GraphCG>::vertex_iterator vertex_iter;
    cout << "vertices(g) occupancy status = ";
    pair<vertex_iter, vertex_iter> vp;  //first iterator points to the beginning,
                                        //second iterator points "past the end" of the vertices
    for (vp = vertices(g); vp.first != vp.second; ++vp.first)
        cout << status[*vp.first] << " ";
  • CG 9:26 am on July 23, 2008 Permalink | Reply
    Tags: ,   

    Customizing Properties 

    Defining my own properties tags to be added to the vertex, edge and graph.

    We have agreed that the information about occupancy of obstacle in the map will be stored in the vertices.

  • CG 5:40 am on July 23, 2008 Permalink | Reply
    Tags: ,   


    converting grid map into a graph representation and configuring the data structure.

  • CG 3:58 am on July 21, 2008 Permalink | Reply
    Tags: assignment   

    New-Age Cryptography – Reading Assignment 

    I’ve been given an assignment to read this paper. Already did some skimming on every page and found a lot of new terminology in cryptography. Pheeww… hard stuff!

    Gonna need to discuss this with the security expert and my fellow students who also doing research in crypto. For now, coding is much more interesting to me 😉

    • soni 8:45 am on July 22, 2008 Permalink | Reply

      never stop touching your coding environment. compile something everyday. improve your skill by challange yourself with debugging small interesting code snippet (although this and that codes is for robotics, hahahahaha)

      someday you will be a master of coder 😀

    • tetangga sebelah 9:02 pm on July 22, 2008 Permalink | Reply

      class programmer: Insane, Anti_Sosial, Cadu_Mandi{

    • Anu 1:33 am on September 5, 2008 Permalink | Reply

      Just wanted to leave a reply.. I was looking for some blogs on Crypto and found yours. The “New Age Cryptography” paper looked interesting. Funny thing is, after the site opened, I realized that it’s authored by the professor I studied under..! Nice coincidence!

    • chikaradirghsa 6:37 pm on September 5, 2008 Permalink | Reply

      @Anu: hey, i have read the paper and still found many things that i don’t understand. it’s too “mathematical” for me, i guess 😀
      are you also a phd student in cryptography?

    • Anu 7:37 pm on September 15, 2008 Permalink | Reply

      Not a Phd student.
      I was a Masters student at Cornell.Got interested in Crypto, so took a couple of classes. The interest in this subject just doesn’t seem to go away!
      P.S. The paper is mathematical for me too!

    • Anu 7:39 pm on September 15, 2008 Permalink | Reply

      You’re a Phd student? Which university are you studying at?

    • chikaradirghsa 7:59 pm on September 15, 2008 Permalink | Reply

      @Anu: maybe we can discuss about the paper? or any topics in crypto? 🙂
      yes i’m a phd student at ITB.

      why don’t you take phd at Cornell? 😉

  • CG 4:18 pm on July 20, 2008 Permalink | Reply
    Tags: feynman, science   

    Scientific Integrity – Feynman 

    Finally managed to finish this book. More about it here and here.

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