几行代码生成漂亮图片，数学家就是牛！
信息获得处：http://news.cnblogs.com/n/501488/
分形：http://baike.baidu.com/subview/83243/11213590.htm?fr=aladdin
代码：[采用宏定义的来选择绘制不同的图，所以把最后两个给注释掉了，因为宏冲突，想自己试试可以单独编译运行]
PS:生成的图片是ppm格式的要用格式工厂之类的软件进行转换，也可以自己在程序里直接把图片生成bmp或者其他格式的~
1 // NOTE: compile with g++ filename.cpp -std=c++11
2 #include <iostream>
3 #include <cmath>
4 #include <cstdlib>
5 #define DIM 1024
6 #define DM1 (DIM-1)
7 #define _sq(x) ((x)*(x)) // square
8 #define _cb(x) abs((x)*(x)*(x)) // absolute value of cube
9 #define _cr(x) (unsigned char)(pow ((x),1.0/3.0)) // cube root
10 #define F
11
12 unsigned char GR (int,int);
13 unsigned char BL (int,int);
14
15 unsigned char RD (int i,int j){
16 #ifdef A
17 return (char)(_sq(cos(atan2(j-512,i-512)/2))*255);
18 #endif
19
20 #ifdef B
21 #define r(n) (rand ()%n)
22 static char c[1024][1024];
23 return!c[i][j]?c[i][j]=!r(999)?r(256):RD ((i+r(2))%1024,(j+r(2))%1024):c[i][j];
24 #endif
25
26 #ifdef C
27 float x=0,y=0;
28 int k;
29 for(k=0;k++<256;){
30 float a=x*x-y*y+ (i-768.0)/512;
31 y=2*x*y+ (j-512.0)/512;
32 x=a;
33 if(x*x+y*y>4)break;
34 }
35 return log (k)*47;
36 #endif
37
38 #ifdef D
39 double a=0,b=0,c,d,n=0;
40 while((c=a*a)+(d=b*b)<4&&n++<880){
41 b=2*a*b+j*8e-9-.645411;
42 a=c-d+i*8e-9+.356888;
43 }
44 return 255*pow ((n-80)/800,3.);
45 #endif
46
47 #ifdef E
48 static double k;
49 k+=rand ()/1./RAND_MAX;
50 int l=k;
51 l%=512;
52 return l>255?511-l:l;
53 #endif
54
55 #ifdef F
56 float s=3./(j+99);
57 float y=(j+sin ((i*i+_sq (j-700)*5)/100./DIM)*35)*s;
58 return (int((i+DIM)*s+y)%2+int((DIM*2-i)*s+y)%2)*127;
59 #endif
60 /*
61 #ifdef G
62 #define D DIM
63 #define M m[(x+D+ (d==0)-(d==2))%D][(y+D+ (d==1)-(d==3))%D]
64 #define R rand ()%D
65 #define B m[x][y]
66 return(i+j)?256-(BL (i,j))/2:0;
67 #endif
68 */
69 /*
70 #ifdef H
71 #define A float a=0,b,k,r,x
72 #define B int e,o
73 #define C (x) x>255?255:x
74 #define R return #define D DIM
75 R BL (i,j)*(D-i)/D;
76 #endif
77 */
78 return 0;
79 }
80 unsigned char GR (int i,int j){
81 #ifdef A
82 return (char)(_sq (cos (atan2(j-512,i-512)/2-2*acos (-1)/3))*255);
83 #endif
84
85 #ifdef B
86 static char c[1024][1024];
87 return!c[i][j]?c[i][j]=!r(999)?r(256):GR ((i+r(2))%1024,(j+r(2))%1024):c[i][j];
88 #endif
89
90 #ifdef C
91 float x=0,y=0;
92 int k;
93 for(k=0;k++<256;){
94 float a=x*x-y*y+ (i-768.0)/512;
95 y=2*x*y+ (j-512.0)/512;
96 x=a;
97 if(x*x+y*y>4)break;
98 }
99 return log (k)*47;
100 #endif
101
102 #ifdef D
103 double a=0,b=0,c,d,n=0;
104 while((c=a*a)+(d=b*b)<4&&n++<880){
105 b=2*a*b+j*8e-9-.645411;
106 a=c-d+i*8e-9+.356888;
107 }
108 return 255*pow ((n-80)/800,.7);
109 #endif
110
111 #ifdef E
112 static double k;
113 k+=rand ()/1./RAND_MAX;
114 int l=k;
115 l%=512;
116 return l>255?511-l:l;
117 #endif
118
119 #ifdef F
120 float s=3./(j+99);
121 float y=(j+sin ((i*i+_sq (j-700)*5)/100./DIM)*35)*s;
122 return (int(5*((i+DIM)*s+y))%2+int(5*((DIM*2-i)*s+y))%2)*127;
123 #endif
124 /*
125 #ifdef G
126 #define A
127 static int m[D][D],e,x,y,d,c[4],f,n;
128 if (i+j<1){
129 for (d=D*D;d;d--){
130 m[d%D][d/D]=d%6?0:rand ()%2000?1:255;
131 }
132 for (n=1 return RD (i,j);
133 #endif
134 */
135 /*
136 #ifdef H
137 #define E DM1
138 #define F static float
139 #define G for (
140 #define H r=a*1.6/D+2.4;x=1.0001*b/D
141 R BL (i,j)*(D-j/2)/D;
142 #endif
143 */
144 return 0;
145 }
146 unsigned char BL (int i,int j){
147 #ifdef A
148 return (char)(_sq (cos (atan2(j-512,i-512)/2+2*acos (-1)/3))*255);
149 #endif
150
151 #ifdef B
152 static char c[1024][1024];
153 return!c[i][j]?c[i][j]=!r(999)?r(256):BL((i+r(2))%1024,(j+r(2))%1024):c[i][j];
154 #endif
155
156 #ifdef C
157 float x=0,y=0;
158 int k;
159 for(k=0;k++<256;){
160 float a=x*x-y*y+ (i-768.0)/512;
161 y=2*x*y+ (j-512.0)/512;
162 x=a;
163 if(x*x+y*y>4)break;
164 }
165 return 128-log (k)*23;
166 #endif
167
168 #ifdef D
169 double a=0,b=0,c,d,n=0;
170 while((c=a*a)+(d=b*b)<4&&n++<880){
171 b=2*a*b+j*8e-9-.645411;
172 a=c-d+i*8e-9+.356888;
173 }
174 return 255*pow ((n-80)/800,.5);
175 #endif
176
177 #ifdef E
178 static double k;
179 k+=rand ()/1./RAND_MAX;
180 int l=k;
181 l%=512;
182 return l>255?511-l:l;
183 #endif
184
185 #ifdef F
186 float s=3./(j+99);
187 float y=(j+sin ((i*i+_sq (j-700)*5)/100./DIM)*35)*s;
188 return (int(29*((i+DIM)*s+y))%2+int(29*((DIM*2-i)*s+y))%2)*127;
189 #endif
190 /*
191 #ifdef G
192 A;n;n++){
193 x=R;y=R;
194 if(B==1){
195 f=1;
196 for(d=0;d<4;d++){
197 c[d]=M;
198 f=f<c[d]?c[d]:f;
199 }
200 if(f>2){B=f-1;}
201 else{
202 ++e%=4;
203 d=e;
204 if(!c[e]){
205 B=0;M=1;
206 }}}}}
207 return m[i][j];
208 #endif
209 */
210 /*
211 #ifdef H
212 F c[D][D];
213 if(i+j<1){A;B;G;a<D;a+=0.1){G b=0;b<D;b++){H;G k=0;k<D;k++){x=r*x*(1-x);
214 if(k>D/2){e=a;o=(E*x);c[e][o]+=0.01;}}}}}
215 R C (c[j][i])*i/D;
216 #endif
217 */
218
219 return 0;
220 }
221
222 void pixel_write (int,int);
223 FILE *fp;
224 int main (){
225 fp = fopen ("MathPic.ppm","wb");
226 fprintf (fp, "P6\n%d %d\n255\n", DIM, DIM);
227 for(int j=0;j<DIM;j++)
228 for(int i=0;i<DIM;i++)
229 pixel_write (i,j);
230 fclose (fp);
231 return 0;
232 }
233 void pixel_write (int i, int j){
234 static unsigned char color[3];
235 color[0] = RD (i,j)&255;
236 color[1] = GR (i,j)&255;
237 color[2] = BL (i,j)&255;
238 fwrite (color, 1, 3, fp);
239 }
http://www.cnblogs.com/zjutlitao/p/3915860.html
