I use loadStrings() method to load all the discrete X,Y coordinates from a txt file. Then I put them in a string array. If I directly put ellipse(X,Y,10,10) under the draw() method, the ball will not move in a constant speed, because the distance between each sets of coordinates is different. As the ball moves in a high density area, it slows down dramatically; as it moves in a discrete area, it moves fast. Is there any way to make it move in a constant speed in the whole route? or should I use some other shape like to create a curve first before draw()?

Here is my scripts:

2. String[] lines;
3. int index=0;
4. 
   
5. void setup(){
6.   lines=loadStrings("positions.txt");
7.   frameRate(12);
8.   noStroke();
9.   background(0);
10. }
11. 
    
12. void draw(){
13.   fill(0,30);
14.   rect(0,0,width,height);
15.   fill(255);
16.   
17.   if(index<lines.length){
18.     String[] pieces=split(lines[index],'\t');
19.     if(pieces.length==2){
20.       int x=int(pieces[0]);
21.       int y=int(pieces[1]);
22.       ellipse(x,y,8,8);
23.     }
24.     index++;
25.   }
26. }

Here is the position.txt:

2. 70 35
3. 69 35
4. 68 39
5. 67 42
6. 66 47
7. 64 51
8. 64 54
9. 63 57
10. 60 60
11. 58 64
12. 51 69
13. 48 72
14. 44 73
15. 39 75
16. 35 75
17. 30 75
18. 25 75
19. 21 75
20. 17 73
21. 13 69
22. 12 66
23. 11 61
24. 11 57
25. 10 49
26. 10 45
27. 10 38
28. 12 32
29. 13 29
30. 16 23
31. 20 19
32. 24 16
33. 27 15
34. 31 13
35. 33 13
36. 37 13
37. 40 15
38. 42 16
39. 45 19
40. 46 21
41. 47 24
42. 48 26
43. 48 29
44. 48 33
45. 47 39
46. 43 45
47. 42 47
48. 38 50
49. 35 51
50. 32 51
51. 30 51
52. 27 50
53. 27 50
54. 26 46
55. 26 41
56. 29 36
57. 30 34
58. 31 33
59. 31 33
60. 32 33
61. 33 33
62. 34 33
63. 34 33
64. 35 33
65. 37 33
66. 39 33
67. 42 32
68. 44 31
69. 46 29
70. 48 29
71. 49 27
72. 52 24
73. 53 23
74. 57 19
75. 61 16
76. 63 14
77. 67 13
78. 69 12
79. 69 12
80. 77 11
81. 77 11
82. 80 11
83. 86 16
84. 90 21
85. 93 25
86. 95 29
87. 95 32
88. 95 33
89. 95 37
90. 94 41
91. 93 44
92. 92 46
93. 91 49
94. 89 51
95. 87 55
96. 85 59
97. 82 62
98. 80 64
99. 79 67
100. 77 69
101. 74 71
102. 68 72
103. 65 73
104. 63 73
105. 62 73
106. 60 72
107. 58 69
108. 57 67
109. 57 66
110. 56 60
111. 56 56
112. 56 54
113. 58 49
114. 60 47
115. 62 47
116. 63 47
117. 67 48
118. 70 52
119. 73 55
120. 74 57
121. 74 58
122. 74 60
123. 74 62
124. 73 65
125. 70 68
126. 67 69
127. 65 70
128. 63 70
129. 62 70
130. 60 68
131. 57 65
132. 55 64
133. 50 62
134. 46 61
135. 40 60
136. 38 60
137. 36 60
138. 32 61
139. 30 62
140. 27 64
141. 26 68
142. 25 71
143. 25 77
144. 25 81
145. 26 84
146. 28 86
147. 31 87
148. 33 88
149. 36 88
150. 39 86
151. 41 85
152. 43 83
153. 44 81
154. 45 76
155. 45 74
156. 45 71
157. 40 67
158. 37 65
159. 34 63
160. 33 61
161. 33 61
162. 32 60
163. 33 49
164. 37 45
165. 41 41
166. 45 39
167. 47 38
168. 51 37
169. 54 37
170. 58 38
171. 61 41
172. 63 44
173. 65 46
174. 66 49
175. 66 51
176. 67 55
177. 67 58
178. 67 60
179. 66 62
180. 64 65
181. 63 66
182. 61 67
183. 60 68
184. 58 68
185. 55 69
186. 54 69
187. 51 69
188. 48 69
189. 46 68
190. 45 66
191. 44 65
192. 44 63
193. 44 61
194. 44 59
195. 44 56
196. 44 55
197. 45 53
198. 47 52
199. 49 50
200. 50 48
201. 51 47
202. 52 46
203. 54 46
204. 55 45
205. 55 45
206. 56 44
207. 57 44

Thanks,

Zhenyang

I am doing my master's thesis on the spatial and temporal patterns of bike flow. I found an exquisite animated map created using Processing, If I have all the bikes' data ( starting and ending time and location), how can I use processing to build the map? I am starting learning Processing now, because I have some programming experience, so to learn it won't be a barrier to me.

Any help will be appreciated!

Zhenyang