c语言函数绘图

代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
#define _XOPEN_SOURCE 500
#define _C99_SOURCE
#include <stdio.h>
#include <math.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <float.h>
//#define LOG_LEVEL DEBUG_LOG
#define DEBUG_LOG 7
#define INFO_LOG 5
#define ERR_LOG 4
#ifndef LOG_LEVEL
#define LOG_LEVEL INFO_LOG
#endif
#ifndef GREATER_CHAR
#define GREATER_CHAR ' '
#endif
#ifndef SMALLER_CHAR
#define SMALLER_CHAR '+'
#endif
void logger(int level, const char *format, ...) {
if(level > LOG_LEVEL) return;
va_list args;
va_start(args, format);
int len = vsnprintf(NULL, 0, format, args)+1;
va_end(args);
va_start(args, format);
char *str = malloc(len);
vsprintf(str, format, args);
va_end(args);
fprintf(stderr, "%s\n", str);
free(str);
}
double x1, x2, _y1, _y2, s1, s2;

#define PUSH(s, n) (s[s##_ptr++] = (n))
#define POP(s, n) (n = s[--s##_ptr])
#define TOP(s, n) (n = s[s##_ptr-1])
#define EMPTY(s) (s##_ptr == 0)
enum {
op_acos = 48,
op_asin ,
op_atan ,
op_cos ,
op_cosh ,
op_sin ,
op_sinh ,
op_tan ,
op_tanh ,
op_exp ,
op_log ,
op_floor ,
op_sqrt ,
op_fabs ,
op_ceil
};
const static int op_min = op_acos;
const static int op_max = op_ceil;

static double stack[1024];
static char op_stack[1024];
static int priv[128] = {
[0 ... 39] = 0,
['('] = 1,
[')'] = 2,
['*'] = 3,
['+'] = 2,
[44] = 0,
['-'] = 2,
[46] = 0,
['/'] = 3,
[48 ... 93] = 0,
['^'] = 4,
[95 ... 127] = 0
};
static int stack_ptr = 0;
static int op_stack_ptr = 0;
void logStack() {
logger(DEBUG_LOG, "op_stack: ");
for(int cnt = 0; cnt < op_stack_ptr; cnt++) {
logger(DEBUG_LOG, "%c ", op_stack[cnt]);
}
logger(DEBUG_LOG, "stack: ");
for(int cnt = 0; cnt < stack_ptr; cnt++) {
logger(DEBUG_LOG, "%lf ", stack[cnt]);
}
logger(DEBUG_LOG, "");
}
void biCheck() {
if(EMPTY(stack)) {
logger(ERR_LOG, "empty stack!");
exit(1);
}
}
void pushOP(char cur_op) {
double n1, n2;
char op;
while(!EMPTY(op_stack) && priv[TOP(op_stack, op)] >= priv[cur_op]) {
POP(op_stack, op);
double res = 0;
POP(stack, n2);
if(!EMPTY(stack))POP(stack, n1);
else n1 = 0;
switch(op) {
case '+':
res = n1 + n2;
break;
case '-':
res = n1 - n2;
break;
case '*':
res = n1 * n2;
break;
case '/':
if(n2 == 0) {
logger(ERR_LOG, "divisor is zeor!");
// exit(1);
}
res = n1 / n2;
break;
case '^':
res = pow(n1, n2);
break;
default:
break;
}
PUSH(stack, res);
}
}
int len_strncmp(const char *a, const char *b) {
return strncmp(a, b, strlen(b));
}
double eval(double y, double x, const char *expr) {
int len = strlen(expr);
int i = 0;
stack_ptr = 0;
op_stack_ptr = 0;
while(i < len) {
switch(expr[i]) {
case '^':
biCheck();
pushOP(expr[i]);
// if(EMPTY(stack)) PUSH(stack, 0);
PUSH(op_stack, expr[i]);
break;
case 'x': case 'X':
PUSH(stack, x);
break;
case 'y': case 'Y':
PUSH(stack, y);
break;
case '(':
PUSH(op_stack, '(');
break;
case ')': {
double n1, n2;
char op;
if(EMPTY(op_stack)) {
logger(ERR_LOG, "no match ')'");
exit(1);
}
pushOP(')');
POP(op_stack, op);
if(TOP(op_stack, op) >= op_min && TOP(op_stack, op) <= op_max) {
POP(op_stack, op);
double n;
if(!EMPTY(stack)) {
POP(stack, n);
} else {
logger(ERR_LOG, "Error : no opvalue");
exit(1);
}
double (*op_func)(double);
switch(op) {
case op_acos:
if(n > 1 || n < -1) return DBL_MAX;
op_func = acos;
break;
case op_asin:
if(n > 1 || n < -1) return DBL_MAX;
op_func = asin;
break;
case op_atan:
op_func = atan;
break;
case op_cos:
op_func = cos;
break;
case op_cosh:
op_func = cosh;
break;
case op_sin:
op_func = sin;
break;
case op_sinh:
op_func = sinh;
break;
case op_tan:
op_func = tan;
break;
case op_tanh:
op_func = tanh;
break;
case op_exp:
op_func = exp;
break;
case op_log:
if(n < 0) return DBL_MAX;
op_func = log;
break;
case op_sqrt:
if(n < 0) return DBL_MAX;
op_func = sqrt;
break;
case op_fabs:
op_func = fabs;
break;
case op_ceil:
op_func = ceil;
break;
case op_floor:
op_func = floor;
break;
}
PUSH(stack, op_func(n));
}
}
break;
case '+':case '-': {
if((i > 0 && expr[i-1] != '(')) { // fix: a-(-b)
// if stack is empty or last op is '(', ‘-’ is an Unary operator
// else it's a Binary operator
biCheck();
pushOP(expr[i]);
} else {
PUSH(stack, 0);
}
PUSH(op_stack, expr[i]);
}
break;
case '*':
case '/':
biCheck();
pushOP(expr[i]);
// if(EMPTY(stack)) PUSH(stack, 0);
PUSH(op_stack, expr[i]);
break;
case 'p': // p1 = 3.14
if(i + 1 < len && expr[i + 1] == 'i') {
PUSH(stack, M_PI);
i++;
} else {
logger(ERR_LOG, "Error 'pi': unknown char(%c)", expr[i]);
exit(1);
}
break;
case 'e': // e = 2.7
PUSH(stack, M_E);
break;
case '0':case '1':case '2':case '3':case '4':case '5':case '6':case '7':case '8':case '9':case '.':
{
double n = 0;
double n1 = 1;
while(i < len) {
if(expr[i] < '0' || expr[i] > '9') {
break;
}
n *= 10;
n += expr[i] - '0';
i++;
}
if(expr[i] == '.') {
i++;
while(i < len && expr[i] != '.') {
if(expr[i] < '0' || expr[i] > '9') {
break;
}
n1 /= 10.0;
n += n1 * (expr[i] - '0');
i++;
}
}if(expr[i] == '.') {
logger(ERR_LOG, "error : two '.' in one number");
exit(1);
}
PUSH(stack, n);
i--;
}
break;
default:
if(!len_strncmp(expr + i, "ACOS")) {
PUSH(op_stack, op_acos);
i+=3;
} else if(!len_strncmp(expr + i, "ASIN")) {
PUSH(op_stack, op_asin);
i+=3;
} else if(!len_strncmp(expr + i, "ATAN")) {
PUSH(op_stack, op_atan);
i+=3;
} else if(!len_strncmp(expr + i, "COS")) {
if(expr[i+3] == 'H') {
PUSH(op_stack, op_cosh);
i+=3;
} else {
PUSH(op_stack, op_cos);
i+=2;
}
} else if(!len_strncmp(expr + i, "SIN")) {
if(expr[i+3] == 'H') {
PUSH(op_stack, op_sinh);
i+=3;
} else {
PUSH(op_stack, op_sin);
i+=2;
}
} else if(!len_strncmp(expr + i, "TAN")) {
if(expr[i+3] == 'H') {
PUSH(op_stack, op_tanh);
i+=3;
} else {
PUSH(op_stack, op_tan);
i+=2;
}
} else if(!len_strncmp(expr + i, "EXP")) {
PUSH(op_stack, op_exp);
i+=2;
} else if(!len_strncmp(expr + i, "LOG")) {
PUSH(op_stack, op_log);
i+=2;
} else if(!len_strncmp(expr + i, "SQRT")) {
PUSH(op_stack, op_sqrt);
i+=3;
} else if(!len_strncmp(expr + i, "FABS")) {
PUSH(op_stack, op_fabs);
i+=3;
} else if(!len_strncmp(expr + i, "CEIL")) {
PUSH(op_stack, op_ceil);
i+=3;
} else if(!len_strncmp(expr + i, "FLOOR")) {
PUSH(op_stack, op_floor);
i+=4;
} else {
logger(ERR_LOG, "Error: unknown char(%c)", expr[i]);
exit(1);
}
break;
}
i++;
logStack();
}
biCheck();
pushOP(0);
logStack();
return stack[0];
}
void INIT(char **argv) {
int i = 0;
_y1 = eval(0, 0, argv[i++]);
_y2 = eval(0, 0, argv[i++]);
s1 = eval(0, 0, argv[i++]);
x1 = eval(0, 0, argv[i++]);
x2 = eval(0, 0, argv[i++]);
s2 = eval(0, 0, argv[i++]);
logger(DEBUG_LOG, "%lf, %lf, %lf, %lf, %lf, %lf\n", _y1, _y2, s1, x1, x2, s2);

}
int main(int argc, char **argv) {
if(argc < 8) {
logger(INFO_LOG, "Usage: %s y1 y2 sy x1 x2 sy expression", argv[0]);
logger(INFO_LOG, "example: %s -1 1 0.125 -1 1 0.0625 \"x*x+y*y-1\" 2>errs.log", argv[0]);
logger(INFO_LOG, "example: %s \"-pi/2\" \"pi/2\" 0.25 \"-3*pi\" \"2*pi\" 0.125 \"y^2-SIN(x+y)^2\" 2>errs.log", argv[0]);
logger(INFO_LOG, "example: %s \"-pi/2\" \"pi/2\" 0.25 \"-3*pi\" \"2*pi\" 0.125 \"y^2-SIN(x)^2\" 2>errs.log", argv[0]);
logger(INFO_LOG, "example: %s \"-2\" \"ACOS(1/2)-pi/4\" 0.125 \"-pi/2\" \"pi/2\" 0.0625 \"y*y+x*x+y-SQRT(y*y+x*x)\" 2>errs.log", argv[0]);
logger(INFO_LOG, "example: %s \"-pi\" \"1\" 0.125 \"-2\" \"2\" 0.0625 \"(ACOS(1-FABS(x))-pi)-y\" \"y-SQRT(1-(FABS(x)-1)^2)\" 2>errs.log", argv[0]);
logger(INFO_LOG, "example: %s \"-1\" \"pi/2\" 0.125 \"-1\" \"1\" 0.0625 \"x*x+(y-FABS(x)^(2.0/3.0))^2-1\" 2>errs.log", argv[0]);

exit(0);
}
INIT(argv + 1);
for(double i = _y2; i >= _y1; ) {
for(double j = x1; j <= x2; ) {
logger(DEBUG_LOG, "x = %lf, y = %lf", j, i);
bool ok = true;
for(char **expr = argv + 7; *expr; expr++) {
if(eval(i, j, *expr) >= 0) {
ok = false;
break;
}
}
if(ok) {
printf("%c", SMALLER_CHAR);
} else {
printf("%c", GREATER_CHAR);
}
j+=s2;
}
printf("\n");
i-=s1;
}
}

example

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
.................................
.........+++++++++++++++.........
......+++++++++++++++++++++......
....+++++++++++++++++++++++++....
...+++++++++++++++++++++++++++...
..+++++++++++++++++++++++++++++..
.+++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++.
..+++++++++++++++++++++++++++++..
...+++++++++++++++++++++++++++...
....+++++++++++++++++++++++++....
......+++++++++++++++++++++......
.........+++++++++++++++.........
.................................

糖葫芦

1
2
3
4
5
6
7
8
9
10
11
12
13
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..+++++++++................+++++++++................++++++++++...............++++++++++...............++++++++++..............
.+++++++++++++++..........+++++++++++++++..........+++++++++++++++..........++++++++++++++++.........++++++++++++++++.........
.+++++++++++++++++++......++++++++++++++++++++.....++++++++++++++++++++.....++++++++++++++++++++.....++++++++++++++++++++.....
.+++++++++++++++++++++++..++++++++++++++++++++++++.++++++++++++++++++++++++.++++++++++++++++++++++++.++++++++++++++++++++++++.
...+++++++++++++++++++++++...++++++++++++++++++++++...++++++++++++++++++++++...++++++++++++++++++++++...++++++++++++++++++++++
.......+++++++++++++++++++.......++++++++++++++++++.......++++++++++++++++++.......++++++++++++++++++.......++++++++++++++++++
............+++++++++++++............+++++++++++++............+++++++++++++............+++++++++++++............++++++++++++++
.................+++++++...................++++++...................++++++...................++++++...................++++++..
..............................................................................................................................
..............................................................................................................................

这个手机上的mathlab都画不了

糖葫芦1

1
2
3
4
5
6
7
8
9
10
11
12
13
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
........++++++++++...............++++++++++...............++++++++++................+++++++++................+++++++++........
.....++++++++++++++++.........++++++++++++++++..........+++++++++++++++..........+++++++++++++++..........+++++++++++++++.....
...++++++++++++++++++++.....++++++++++++++++++++.....++++++++++++++++++++......+++++++++++++++++++......++++++++++++++++++++..
.++++++++++++++++++++++++.++++++++++++++++++++++++.++++++++++++++++++++++++.++++++++++++++++++++++++..++++++++++++++++++++++++
..++++++++++++++++++++++...++++++++++++++++++++++...++++++++++++++++++++++...+++++++++++++++++++++++..+++++++++++++++++++++++.
....++++++++++++++++++.......++++++++++++++++++.......++++++++++++++++++.......++++++++++++++++++........++++++++++++++++++...
......++++++++++++++............+++++++++++++............+++++++++++++............+++++++++++++............+++++++++++++......
..........++++++...................++++++...................++++++...................++++++....................++++++.........
..............................................................................................................................
..............................................................................................................................

笛卡尔心

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
...................................................
............++++++++++++...++++++++++++............
..........+++++++++++++++++++++++++++++++..........
........+++++++++++++++++++++++++++++++++++........
.......+++++++++++++++++++++++++++++++++++++.......
......+++++++++++++++++++++++++++++++++++++++......
.....+++++++++++++++++++++++++++++++++++++++++.....
.....+++++++++++++++++++++++++++++++++++++++++.....
.....+++++++++++++++++++++++++++++++++++++++++.....
.....+++++++++++++++++++++++++++++++++++++++++.....
.....+++++++++++++++++++++++++++++++++++++++++.....
......+++++++++++++++++++++++++++++++++++++++......
.......++++++++++++++++++++++++++++++++++++++......
........++++++++++++++++++++++++++++++++++++.......
.........+++++++++++++++++++++++++++++++++.........
...........++++++++++++++++++++++++++++++..........
.............+++++++++++++++++++++++++.............
................+++++++++++++++++++................
.......................+++++.......................

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
.................................................................
.........+++++++++++++++.................+++++++++++++++.........
......+++++++++++++++++++++...........+++++++++++++++++++++......
....+++++++++++++++++++++++++.......+++++++++++++++++++++++++....
...+++++++++++++++++++++++++++.....+++++++++++++++++++++++++++...
..+++++++++++++++++++++++++++++...+++++++++++++++++++++++++++++..
.+++++++++++++++++++++++++++++++.+++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++.+++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++.+++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
..+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++..
..+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++..
....+++++++++++++++++++++++++++++++++++++++++++++++++++++++++....
.....+++++++++++++++++++++++++++++++++++++++++++++++++++++++.....
......+++++++++++++++++++++++++++++++++++++++++++++++++++++......
........+++++++++++++++++++++++++++++++++++++++++++++++++........
..........+++++++++++++++++++++++++++++++++++++++++++++..........
...........+++++++++++++++++++++++++++++++++++++++++++...........
.............+++++++++++++++++++++++++++++++++++++++.............
...............+++++++++++++++++++++++++++++++++++...............
.................+++++++++++++++++++++++++++++++.................
...................+++++++++++++++++++++++++++...................
.....................+++++++++++++++++++++++.....................
.......................+++++++++++++++++++.......................
.........................+++++++++++++++.........................
...........................+++++++++++...........................
............................+++++++++............................
.............................+++++++.............................
..............................+++++..............................
...............................+++...............................
................................+................................
................................+................................
................................+................................

还是心

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
.................................
...++++++++...........++++++++...
..+++++++++++.......+++++++++++..
.++++++++++++++...++++++++++++++.
.+++++++++++++++.+++++++++++++++.
.+++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++.
.+++++++++++++++++++++++++++++++.
..+++++++++++++++++++++++++++++..
..+++++++++++++++++++++++++++++..
...+++++++++++++++++++++++++++...
....+++++++++++++++++++++++++....
.....+++++++++++++++++++++++.....
.......+++++++++++++++++++.......
........+++++++++++++++++........
.........+++++++++++++++.........
...........+++++++++++...........
............+++++++++............
..............+++++..............
...............+++...............
................+................

九心连珠

1
2
3
4
5
6
7
8
N=5
size=1
for i in `seq $N`; do
./a.out "-pi" "1" 0.04 "-2/$size" "2/$size" 0.02 "(ACOS(1-FABS($size*x))-pi)-$size*y" "$size*y-SQRT(1-(FABS($size*x)-1)^2)" 2>errs.log 1>out.$i
size=$(echo "scale = 8; $size * sqrt(2)" | bc)
echo $size
done
paste `for i in $(seq $N | tr ' ' '\n'| tac | tr '\n' ' '); do echo out.$i; done;for i in $(seq 2 $N); do echo out.$i; done` > out.paste
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
                                 	                                                	                                                                   	                                                                                               	                                                                                                                                      	                                                                                               	                                                                   	                                                	                                  
+++++++++++++++++++++++ +++++++++++++++++++++++
++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++
++++++ +++++++ ++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++ ++++++ +++++++
++++++++++++++++++++ ++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++ ++++++++++++++++++++
+++++++++++++++++++++++++++ +++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++ +++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++
+++++++++++++ +++++++++++++ ++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++ +++++++++++++ +++++++++++++
++++++++++++++++++++ ++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++ ++++++++++++++++++++
+++++++ ++++++ ++++++++++++++++++++++++ +++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++ +++++++++++++++++++++++++ +++++++ ++++++
++++++++++++++ ++++++++++++++ ++++++++++++++++++++++++++++ +++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++ +++++++++++++++++++++++++++ ++++++++++++++ ++++++++++++++
++++++++ +++++++ +++++++++++++++++++ ++++++++++++++++++ ++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++ +++++++++++++++++++ ++++++++++++++++++ ++++++++ +++++++
+++++++++++++ +++++++++++++ +++++++++++++++++++++ +++++++++++++++++++++ ++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++ +++++++++++++++++++++ +++++++++++++++++++++ +++++++++++++ +++++++++++++
+++++++++++++++ +++++++++++++++ +++++++++++++++++++++++ ++++++++++++++++++++++ ++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++ +++++++++++++++++++++++ ++++++++++++++++++++++ +++++++++++++++ +++++++++++++++
+++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++
+++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++
++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++
++++++++++++++++++ ++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++ ++++++++++++++++++
++++++++++++++ +++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++ ++++++++++++++
++++++++++ ++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++ ++++++++++
++++++ ++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++ ++++++
++++ ++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++ ++++
++ ++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++ ++
++++++++++++ ++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++ ++++++++++++
++++++++ ++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++ ++++++++
++++++ ++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++ ++++++
++++ ++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++ ++++
++ ++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++ ++
+++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++
++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++
++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++ ++++++++++
++++++++ ++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++ ++++++++
++++++ ++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++ ++++++
++++ ++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++ ++++
++ +++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++ ++
+ +++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++ +
+++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++
++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++
+++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++
++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++
+++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++
+++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++
+++++ ++++++++++++++++++++++++++++++++++++++++++++++ +++++
+++ ++++++++++++++++++++++++++++++++++++++++++ +++
++ +++++++++++++++++++++++++++++++++++++++ ++
+ +++++++++++++++++++++++++++++++++++ +
+ ++++++++++++++++++++++++++++++++ +
++++++++++++++++++++++++++++
+++++++++++++++++++++++++
++++++++++++++++++++++
+++++++++++++++++++
++++++++++++++++
++++++++++++++
++++++++++++
++++++++++
++++++++
++++++
++++
+++
++
+



支持生成png

支持生成图片,精确度大大提高了,可以考虑绘制曲线而不是区域了

设置一个精确度,计算结果绝对值小于他的都被认为是0,就可以画曲线了

问题1

ysqrt(x)=0y-sqrt(x)=0x=0x=0附近断断续续

实际上是这个地方变化率太高,x、y的轻微变化导致超出了精确度,有些地方dzdy\frac{dz}{dy}过大而dzdx\frac{dz}{dx}不大时(或二者都很大时),也会断断续续,然而当计算时的xy坐标选取在当前像素点内的某个位置时,可能就可以小于精确度。
z=ysqrt(x)z=y-sqrt(x),分别计算z对x,y的偏导,计算上下左右四个方向的取最大值。
计算点(x+i/max(dzdx,dzdy),y+i/max(dzdx,dzdy))(x+i/max(\frac{dz}{dx},\frac{dz}{dy}),y+i/max(\frac{dz}{dx},\frac{dz}{dy}))处的函数值,若小于精确度,对该像素点绘制,否则不绘制
其中1<i<max(dzdx,dzdy)1<i<max(\frac{dz}{dx},\frac{dz}{dy})

问题2

在某些曲线的交点处,如y2sin(x)2=0y^2-sin(x)^2=0,当x=kpix=k*pi时,线条很粗

实际上是这个地方变化率太低,x或y的变化无法引起z的变化超过设定的变化率时,就会出现这种情况,令z=y2sin(x)2z=y^2-sin(x)^2,分别计算z对x,y的变化量的绝对值z(x0+dx,y0)z(x0,y0)|z(x_0+dx,y_0) - z(x_0,y_0),z(x0,y0+dy)z(x0,y0)|z(x_0,y_0+dy) - z(x_0,y_0),z(x0dx,y0)z(x0,y0)|z(x_0-dx,y_0) - z(x_0,y_0),z(x0,y0dy)z(x0,y0)|z(x_0,y_0-dy) - z(x_0,y_0),将精确度设置为变化量绝对值的最大值即可,对于导数非常大的位置,会导致精确度被无限放大,此时精确度不许大于max(dx,dy)max(dx,dy)

作者

Meow Meow Liu

发布于

2023-10-22

更新于

2024-04-23

许可协议

评论