Processing Forum

How to pass a String variable into sqlite query?

[3 Replies]
- 04-Oct-2012 11:14 AM
- Forum: Contributed Library Questions
Hi, sorry for asking so much but its hard to find doc on the sqlite library. I have another problem,

I want to make a query based on the name of the street, but i have to pass it from a variable, like using "+mystreetString+"

But it doesn't work. It does work however if my variable is an int and not a String, i guess because String is a class and int is a primitive / datatype? If i just type the name of the street in the query command it works fine too, but it doesnt help me much. Here's the code, i've commented out the lines that work in case u want to test:

Thanks for the help, by the way, queries are really slow... is this normal? my database is just 27 mb, i actually transfered all my files to a database cuz i thought it would process data much faster but it seems to be even slower.
2. import de.bezier.data.sql.*;
4. SQLite db;
6. void setup()
7. {
8. size( 400, 400);
9. db = new SQLite( this, "data/sevilla_price_map.db" );
10. }
12. void draw(){
13. String street="Calle Regina";
14. int daytoday=day()-2;// u see, my database is not up to date...
15. int input_price=2700;
16. if ( db.connect() && frameCount==20) {
17. db.query("SELECT * FROM variable_data WHERE \"idname\"="+street+" AND \"day\"="+daytoday+" AND \"month\"="+month()+" AND \"year\"="+year()+"");
18. //db.query("SELECT * FROM variable_data WHERE \"idname\"=\"Calle Regina\" AND \"day\"="+daytoday+" AND \"month\"="+month()+" AND \"year\"="+year()+"");
19. //db.query("SELECT * FROM variable_data WHERE \"stPrice\"="+input_price+" AND \"day\"="+daytoday+" AND \"month\"="+month()+" AND \"year\"="+year()+"");
21. while (db.next ()) {
23. String name=db.getString("idname");
24. int price=db.getInt("stPrice");
26. println(price);
27. println(name);
28. }
29. }
30. println(frameCount);
31. }

How to prepare statements using the sqlite library? [sqlite]

[3 Replies]
- 04-Oct-2012 08:28 AM
- Forum: Contributed Library Questions
So, not much more to add to that, does anybody have an example of how to prepare an sqlite statement and then use it in a loop for instance?

Thanks

sqlite & ArrayList 2.0 array just repeats the last record all the way through

[4 Replies]
- 03-Oct-2012 05:29 PM
- Forum: Contributed Library Questions
Hi there, im reading from a pretty simple database and all works fine except when i want to populate an arraylist with the records, for some reason it just keeps the last records of the loop. Can anybody see if im doing something wrong? Here's the code: thanks!
2. import de.bezier.data.sql.*;
3. SQLite db;
5. Vertexgroup[] vgList=new Vertexgroup[0];
7. void setup(){
8. size(400,400);
10. db = new SQLite( this, "data/sevilla_price_map.db" );
12. prepareVG();
14. for(int i=0;i<vgList.length;i++){
15. println(vgList[i].data.size());
16. for(int j=0;j<vgList[i].data.size();j++){
17. Float x=vgList[i].data.get(j);
18. println(x);
19. }
20. }
21. }
23. void prepareVG() {
24. int idlocalprev=0;
25. float coordx;
26. String idname;
27. ArrayList<Float> data=new ArrayList();
29. if ( db.connect() ) {
30. db.query("SELECT * FROM base_cartography LIMIT 2000");
31. while (db.next()) {
33. idname=db.getString("idname");
34. coordx=db.getFloat("coordx");
35. int idlocal=db.getInt("idlocal");
37. data.add(coordx);
39. if(idlocal<=idlocalprev){
40. Vertexgroup v=new Vertexgroup(idname, coordx, data);
41. vgList=(Vertexgroup[]) append(vgList, v);
42. data.clear();
43. }
44. idlocalprev=idlocal;
45. }
46. }
47. db.close();
48. }
50. class Vertexgroup{
51. ArrayList<Float> data;
52. String idname;
53. float coordx;
54. Vertexgroup(String _idname, float _coordx, ArrayList<Float> _data){
55. idname=_idname;
56. coordx=_coordx;
57. data=_data;
58. }
59. }

Custom draw line function, why does coordinate orientation slow down the program?

[10 Replies]

24-Aug-2012 09:07 AM
Forum: Programming Questions

I am writting my own draw line function in processing to improve speed when drawing large sets of lines from vector file (just a .txt with a bunch of coordinates that draw the map of seville). I am using the method pixel[int] to build such function but for some reason that i can not explain the program goes really fast when i enter the coordinates like this: drawline(y1,x1,y2,x2) but quite slow when its how its supposed to be: drawline(x1,y1,x2,y2) Is there a logical explanation for this?

The structure of the .txt code is simple and it goes like this: folder

The code of the Processing 1.5.1 sketch is below together with the structure of the .txt file, i have shortened it as much as possible and made it as tidy as I could. Thanks for the help!

1188156570;1188156570;37.417595;-5.9971519
1188156400;1188156400;37.4175115;-5.9970483
1188156720;1188156720;37.4174588;-5.9969338
1188156606;1188156606;37.4175833;-5.9966021
1188156462;1188156462;37.4177174;-5.9960534
1188156753;1188156753;37.4177413;-5.9958605
1188156643;1188156643;37.417703;-5.9955831
1132983943;1132983943;37.4176646;-5.995381
next
304791377;304791377;37.3968538;-6.0066269
1188156644;1188156644;37.3967509;-6.0064412
1188156521;1188156521;37.3956275;-6.0073602
next
1188216699;1188216699;37.4221365;-5.9959761
693311201;693311201;37.4253619;-5.9951655
1188216625;1188216625;37.4239123;-5.9924734
1188216567;1188216567;37.4233085;-5.9916937
1186512382;1186512382;37.4223597;-5.9910465
1188216642;1188216642;37.4216335;-5.9927836
1188216699;1188216699;37.4221365;-5.9959761
next

String[] polylines;
String[] streetArray=new String[0];
String[] empty=new String[0];
ArrayList vlist=new ArrayList();
float panX; float panY;

void setup() {
  size(600, 600);
  polylines=loadStrings("data/MapSeville.txt");
  panX=0; panY=0;
  prepare();
}

void draw() {
  background(255);
  PVector pan = pan();
  panX=panX+pan.x;
  panY=panY+pan.y;

  loadPixels();
  for(int i=0;i<vlist.size();i++){
    vertexgroup vg= (vertexgroup) vlist.get(i);
    for(int j=1;j<vg.listcoord.size();j++){
      Vertice v2=(Vertice) vg.listcoord.get((j-1));
      Vertice v1=(Vertice) vg.listcoord.get(j);
      float x1=v1.coord.x+panX;
      float y1=v1.coord.y+panY;
      float x2=v2.coord.x+panX;
      float y2=v2.coord.y+panY;
      drawline(x1, y1, x2, y2);//slow :( comment out this line and enable the next to see how smooth it can go
      //drawline(y1, x1, y2, x2);//fast!
    }
  } 
  updatePixels();
}

////////////////////////////// functions ////////////////////////////////////////////////

PVector pan(){
  PVector p;
  if (mousePressed){
    p = new PVector(mouseX-pmouseX, mouseY-pmouseY);
  }else{
    p=new PVector(0,0);
  }
  return p;
}

////////////////////

void drawline(float x1, float y1, float x2, float y2){
  int X1=int(x1);
  int X2=int(x2);
  color pink = color(0);
    if((X2>X1)){
      for (int i=0; i<=int(x2-x1); i++){ 
        if (((i+X1)>=0)&&((i+X1)<=width)){
          int g=int(y1+((y2-y1)/(x2-x1))*i)*(width) + i + X1;
          if ((g<width*height)&&(g>=0)){
            pixels[g]=pink;
          }
        }
      }
    }else if((X2<X1)){
      for (int i=0; i<=int(x1-x2); i++){
        if (((i+X2)>=0)&&((i+X2)<=width)){
          int f=int(y2+((y2-y1)/(x2-x1))*i)*(width) + i + X2;
          if ((f<width*height)&&(f>=0)){
            pixels[f]=pink; 
        }
      }
    }  
  }
}

//////////////////////////////

 void prepare(){
  for (int i=1;i<polylines.length;i++) {
    String[] pts = split(polylines[i], ";");

    if (pts.length>3) {
      streetArray=append(streetArray, polylines[i]); //adds coords strings to the array streetArray
    }
    if (pts.length==1) { //this is when the coords of a polyline ends: pts[0]==>"next" 
        vertexgroup vgroup;
        vgroup=new vertexgroup(create_polyArr(streetArray)); // this function is defined right below
        vlist.add(vgroup);
        streetArray=empty;
    }}}

    ArrayList create_polyArr(String[] streetpts) {
    ArrayList arrpts=new ArrayList();
    arrpts.clear();

    for (int i=0;i<streetpts.length;i++){ //iterates through coords strings of the polyline contained in streetpts
      String[] pts = split(streetpts[i], ";");
      float x=float(pts[3]);//get the x coord
      float y=float(pts[2]);//get the y coord
      x=((x+5.95)*15000+width/2);//scale and center coord x
      y=((-y+37.40)*15000+height/2);//scale and center coord y
      PVector coord=new PVector(x,y);
      Vertice govertex=new Vertice(coord);
      arrpts.add(govertex);
    }
    return(arrpts);
  }

 ////////////////////// end functions //////////////////////////////////

 //////////////////////// classes ///////////////////////////////////////

 class vertexgroup{

  ArrayList listcoord;

  vertexgroup(ArrayList _listcoord){
    listcoord=_listcoord;
  }}

  //////////

  class Vertice{

  PVector coord;

  Vertice(PVector _coord){
    coord=_coord;
  }}

  ////////////////////// end classes ///////////////////////////////////////

Update# I have uploaded both versions to my website on processing.js, now the fast version works more or smooth ok and the slow one simply doesnt move at all. See here: [fast]( http://417i.com/StackOverflow/FastMap/) and [slow]( http://417i.com/StackOverflow/SlowMap/)

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