Merry X‘mas 圣诞福利－用SAS画圣诞树-经管之家官网！

圣诞快到了，看看SAS大牛（Rick Wicklin）给的圣诞福利吧。
羡慕吧？来玩一把吧，哈哈。

1. proc iml;
   
2. /* Using SAS to construct a Christmas Tree from an iterated function system,
   
3. and adding ornaments and a star.
   
4. Rick Wicklin 12/14/2012
   
5. To construct an iterated function system in SAS, see
   
6. http://blogs.sas.com/content/iml/2012/12/12/iterated-function-systems-and-barnsleys-fern-in-sas/
   
7. */
   
8. /* 1. Each row is a 2x2 linear transforamtion */
   
9. /* Christmas tree */
   
10. L = {0.03 0 0 0.1,
    
11. 0.85 0.000.00 0.85,
    
12. 0.8 0.000.00 0.8,
    
13. 0.2 -0.080.15 0.22,
    
14. -0.20.080.15 0.22,
    
15. 0.25 -0.10.12 0.25,
    
16. -0.20.10.12 0.2};
    
17. /* ... and each row is a translation vector */
    
18. B = {0 0,
    
19. 0 1.5,
    
20. 0 1.5,
    
21. 0 0.85,
    
22. 0 0.85,
    
23. 0 0.3,
    
24. 0 0.4
    
25. };
    
26. prob = { 0.02 0.6 0.1 0.07 0.07 0.07 0.07};
    
27. /* For convenience, transpose the L and B matrices */
    
28. L = L`; B = B`;
    
29. 
    
30. /* 3. iterate the discrete stochastic map */
    
31. N = 1e5; /* number of iterations */
    
32. x = j(2,N); k = j(N,1);
    
33. x[,1] = {0, 2}; /* initial point */
    
34. call randseed(1);
    
35. call randgen(k, "Table", prob);
    
36. 
    
37. do i = 2 to N;
    
38. x[,i] = shape(L[,k[i]], 2)*x[,i-1] + B[,k[i]];
    
39. end;
    
40. 
    
41. /* 4. plot the iteration history */
    
42. y = x`;
    
43. create IFS from y[c={"x" "y"}]; append from y; close IFS;
    
44. 
    
45. /* just for fun, create ornaments and colors */
    
46. idx = ceil(N*ranuni(j(500,1)));
    
47. x1 = x[1,idx]`;
    
48. jdx = loc(abs(x1)>0.04);
    
49. idx = idx[jdx];
    
50. x1 = x[1,idx]`;
    
51. y1 = x[2,idx]` - 0.1;
    
52. group = ceil(5*ranuni(j(nrow(idx),1)));
    
53. create Ornaments var {x1 y1 group}; append; close Ornaments;
    
54. quit;
    
55. 
    
56. /* basic IFS Christmas Tree */
    
57. ods graphics / width=200px height=400px;
    
58. proc sgplot data=IFS;
    
59. title "SAS Christmas Tree";
    
60. scatter x=x y=y / markerattrs=(size=1 color=ForestGreen);
    
61. yaxis display=none;
    
62. xaxis display=none;
    
63. run;
    
64. 
    
65. /* Add ornaments and star */
    
66. data Star;
    
67. x2=0; y2=10; output;
    
68. run;
    
69. 
    
70. data All;
    
71. merge IFS Ornaments Star;
    
72. if group=. then group=1;
    
73. run;
    
74. 
    
75. data Attrs;
    
76. length Value MarkerColor $20;
    
77. ID = "Ornaments";
    
78. Value = 1; MarkerColor = "Red "; output;
    
79. Value = 2; MarkerColor = "Blue "; output;
    
80. Value = 3; MarkerColor = "Purple "; output;
    
81. Value = 4; MarkerColor = "Gold "; output;
    
82. Value = 5; MarkerColor = "Chartreuse"; output;
    
83. run;
    
84. 
    
85. *ods graphics / width=400px height=800px;
    
86. proc sgplot data=All noautolegend dattrmap=Attrs;
    
87. title "SAS Christmas Tree";
    
88. scatter x=x y=y / markerattrs=(size=1 color=ForestGreen);
    
89. scatter x=x1 y=y1 / transparency=0.33 attrid=Ornaments
    
90. markerattrs=(size=8 symbol=CircleFilled) group=group;
    
91. scatter x=x2 y=y2 / markerattrs=(color=Gold size=15 symbol=StarFilled);
    
92. yaxis display=none;
    
93. xaxis display=none;
    
94. run;

复制代码
http://data:image/png;base64,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