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24 | </div> | |
25 | <div class="section"> | |
26 | <div class="titlepage"><div><div><h3 class="title"> | |
27 | <a name="math_toolkit.pol_ref.error_handling_policies"></a><a class="link" href="error_handling_policies.html" title="Error Handling Policies">Error Handling | |
28 | Policies</a> | |
29 | </h3></div></div></div> | |
30 | <p> | |
31 | There are two orthogonal aspects to error handling: | |
32 | </p> | |
33 | <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> | |
34 | <li class="listitem"> | |
35 | What to do (if anything) with the error. | |
36 | </li> | |
37 | <li class="listitem"> | |
38 | What kind of error is being raised. | |
39 | </li> | |
40 | </ul></div> | |
41 | <h5> | |
42 | <a name="math_toolkit.pol_ref.error_handling_policies.h0"></a> | |
43 | <span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.available_actions_when_an_error_"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.available_actions_when_an_error_">Available | |
44 | Actions When an Error is Raised</a> | |
45 | </h5> | |
46 | <p> | |
47 | What to do with the error is encapsulated by an enumerated type: | |
48 | </p> | |
49 | <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">math</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">policies</span> <span class="special">{</span> | |
50 | ||
51 | <span class="keyword">enum</span> <span class="identifier">error_policy_type</span> | |
52 | <span class="special">{</span> | |
53 | <span class="identifier">throw_on_error</span> <span class="special">=</span> <span class="number">0</span><span class="special">,</span> <span class="comment">// throw an exception.</span> | |
54 | <span class="identifier">errno_on_error</span> <span class="special">=</span> <span class="number">1</span><span class="special">,</span> <span class="comment">// set ::errno & return 0, NaN, infinity or best guess.</span> | |
55 | <span class="identifier">ignore_error</span> <span class="special">=</span> <span class="number">2</span><span class="special">,</span> <span class="comment">// return 0, NaN, infinity or best guess.</span> | |
56 | <span class="identifier">user_error</span> <span class="special">=</span> <span class="number">3</span> <span class="comment">// call a user-defined error handler.</span> | |
57 | <span class="special">};</span> | |
58 | ||
59 | <span class="special">}}}</span> <span class="comment">// namespaces</span> | |
60 | </pre> | |
61 | <p> | |
62 | The various enumerated values have the following meanings: | |
63 | </p> | |
64 | <h6> | |
65 | <a name="math_toolkit.pol_ref.error_handling_policies.h1"></a> | |
66 | <span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.throw_on_error"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.throw_on_error">throw_on_error</a> | |
67 | </h6> | |
68 | <p> | |
69 | Will throw one of the following exceptions, depending upon the type of the | |
70 | error: | |
71 | </p> | |
72 | <div class="informaltable"><table class="table"> | |
73 | <colgroup> | |
74 | <col> | |
75 | <col> | |
76 | </colgroup> | |
77 | <thead><tr> | |
78 | <th> | |
79 | <p> | |
80 | Error Type | |
81 | </p> | |
82 | </th> | |
83 | <th> | |
84 | <p> | |
85 | Exception | |
86 | </p> | |
87 | </th> | |
88 | </tr></thead> | |
89 | <tbody> | |
90 | <tr> | |
91 | <td> | |
92 | <p> | |
93 | Domain Error | |
94 | </p> | |
95 | </td> | |
96 | <td> | |
97 | <p> | |
98 | std::domain_error | |
99 | </p> | |
100 | </td> | |
101 | </tr> | |
102 | <tr> | |
103 | <td> | |
104 | <p> | |
105 | Pole Error | |
106 | </p> | |
107 | </td> | |
108 | <td> | |
109 | <p> | |
110 | std::domain_error | |
111 | </p> | |
112 | </td> | |
113 | </tr> | |
114 | <tr> | |
115 | <td> | |
116 | <p> | |
117 | Overflow Error | |
118 | </p> | |
119 | </td> | |
120 | <td> | |
121 | <p> | |
122 | std::overflow_error | |
123 | </p> | |
124 | </td> | |
125 | </tr> | |
126 | <tr> | |
127 | <td> | |
128 | <p> | |
129 | Underflow Error | |
130 | </p> | |
131 | </td> | |
132 | <td> | |
133 | <p> | |
134 | std::underflow_error | |
135 | </p> | |
136 | </td> | |
137 | </tr> | |
138 | <tr> | |
139 | <td> | |
140 | <p> | |
141 | Denorm Error | |
142 | </p> | |
143 | </td> | |
144 | <td> | |
145 | <p> | |
146 | std::underflow_error | |
147 | </p> | |
148 | </td> | |
149 | </tr> | |
150 | <tr> | |
151 | <td> | |
152 | <p> | |
153 | Evaluation Error | |
154 | </p> | |
155 | </td> | |
156 | <td> | |
157 | <p> | |
158 | boost::math::evaluation_error | |
159 | </p> | |
160 | </td> | |
161 | </tr> | |
162 | <tr> | |
163 | <td> | |
164 | <p> | |
165 | Indeterminate Result Error | |
166 | </p> | |
167 | </td> | |
168 | <td> | |
169 | <p> | |
170 | std::domain_error | |
171 | </p> | |
172 | </td> | |
173 | </tr> | |
174 | </tbody> | |
175 | </table></div> | |
176 | <h6> | |
177 | <a name="math_toolkit.pol_ref.error_handling_policies.h2"></a> | |
178 | <span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.errno_on_error"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.errno_on_error">errno_on_error</a> | |
179 | </h6> | |
180 | <p> | |
181 | Will set global <a href="http://en.wikipedia.org/wiki/Errno" target="_top"><code class="computeroutput"><span class="special">::</span><span class="identifier">errno</span></code></a> | |
182 | <code class="computeroutput"><span class="special">::</span><span class="identifier">errno</span></code> | |
183 | to one of the following values depending upon the error type (often EDOM | |
184 | = 33 and ERANGE = 34), and then return the same value as if the error had | |
185 | been ignored: | |
186 | </p> | |
187 | <div class="informaltable"><table class="table"> | |
188 | <colgroup> | |
189 | <col> | |
190 | <col> | |
191 | </colgroup> | |
192 | <thead><tr> | |
193 | <th> | |
194 | <p> | |
195 | Error Type | |
196 | </p> | |
197 | </th> | |
198 | <th> | |
199 | <p> | |
200 | errno value | |
201 | </p> | |
202 | </th> | |
203 | </tr></thead> | |
204 | <tbody> | |
205 | <tr> | |
206 | <td> | |
207 | <p> | |
208 | Domain Error | |
209 | </p> | |
210 | </td> | |
211 | <td> | |
212 | <p> | |
213 | EDOM | |
214 | </p> | |
215 | </td> | |
216 | </tr> | |
217 | <tr> | |
218 | <td> | |
219 | <p> | |
220 | Pole Error | |
221 | </p> | |
222 | </td> | |
223 | <td> | |
224 | <p> | |
225 | EDOM | |
226 | </p> | |
227 | </td> | |
228 | </tr> | |
229 | <tr> | |
230 | <td> | |
231 | <p> | |
232 | Overflow Error | |
233 | </p> | |
234 | </td> | |
235 | <td> | |
236 | <p> | |
237 | ERANGE | |
238 | </p> | |
239 | </td> | |
240 | </tr> | |
241 | <tr> | |
242 | <td> | |
243 | <p> | |
244 | Underflow Error | |
245 | </p> | |
246 | </td> | |
247 | <td> | |
248 | <p> | |
249 | ERANGE | |
250 | </p> | |
251 | </td> | |
252 | </tr> | |
253 | <tr> | |
254 | <td> | |
255 | <p> | |
256 | Denorm Error | |
257 | </p> | |
258 | </td> | |
259 | <td> | |
260 | <p> | |
261 | ERANGE | |
262 | </p> | |
263 | </td> | |
264 | </tr> | |
265 | <tr> | |
266 | <td> | |
267 | <p> | |
268 | Evaluation Error | |
269 | </p> | |
270 | </td> | |
271 | <td> | |
272 | <p> | |
273 | EDOM | |
274 | </p> | |
275 | </td> | |
276 | </tr> | |
277 | <tr> | |
278 | <td> | |
279 | <p> | |
280 | Indeterminate Result Error | |
281 | </p> | |
282 | </td> | |
283 | <td> | |
284 | <p> | |
285 | EDOM | |
286 | </p> | |
287 | </td> | |
288 | </tr> | |
289 | </tbody> | |
290 | </table></div> | |
291 | <h6> | |
292 | <a name="math_toolkit.pol_ref.error_handling_policies.h3"></a> | |
293 | <span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.ignore_error"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.ignore_error">ignore_error</a> | |
294 | </h6> | |
295 | <p> | |
296 | Will return one of the values below depending on the error type (<code class="computeroutput"><span class="special">::</span><span class="identifier">errno</span></code> | |
297 | is NOT changed):: | |
298 | </p> | |
299 | <div class="informaltable"><table class="table"> | |
300 | <colgroup> | |
301 | <col> | |
302 | <col> | |
303 | </colgroup> | |
304 | <thead><tr> | |
305 | <th> | |
306 | <p> | |
307 | Error Type | |
308 | </p> | |
309 | </th> | |
310 | <th> | |
311 | <p> | |
312 | Returned Value | |
313 | </p> | |
314 | </th> | |
315 | </tr></thead> | |
316 | <tbody> | |
317 | <tr> | |
318 | <td> | |
319 | <p> | |
320 | Domain Error | |
321 | </p> | |
322 | </td> | |
323 | <td> | |
324 | <p> | |
325 | std::numeric_limits<T>::quiet_NaN() | |
326 | </p> | |
327 | </td> | |
328 | </tr> | |
329 | <tr> | |
330 | <td> | |
331 | <p> | |
332 | Pole Error | |
333 | </p> | |
334 | </td> | |
335 | <td> | |
336 | <p> | |
337 | std::numeric_limits<T>::quiet_NaN() | |
338 | </p> | |
339 | </td> | |
340 | </tr> | |
341 | <tr> | |
342 | <td> | |
343 | <p> | |
344 | Overflow Error | |
345 | </p> | |
346 | </td> | |
347 | <td> | |
348 | <p> | |
349 | std::numeric_limits<T>::infinity() | |
350 | </p> | |
351 | </td> | |
352 | </tr> | |
353 | <tr> | |
354 | <td> | |
355 | <p> | |
356 | Underflow Error | |
357 | </p> | |
358 | </td> | |
359 | <td> | |
360 | <p> | |
361 | 0 | |
362 | </p> | |
363 | </td> | |
364 | </tr> | |
365 | <tr> | |
366 | <td> | |
367 | <p> | |
368 | Denorm Error | |
369 | </p> | |
370 | </td> | |
371 | <td> | |
372 | <p> | |
373 | The denormalised value. | |
374 | </p> | |
375 | </td> | |
376 | </tr> | |
377 | <tr> | |
378 | <td> | |
379 | <p> | |
380 | Evaluation Error | |
381 | </p> | |
382 | </td> | |
383 | <td> | |
384 | <p> | |
385 | The best guess (perhaps NaN) as to the result: which may be significantly | |
386 | in error. | |
387 | </p> | |
388 | </td> | |
389 | </tr> | |
390 | <tr> | |
391 | <td> | |
392 | <p> | |
393 | Indeterminate Result Error | |
394 | </p> | |
395 | </td> | |
396 | <td> | |
397 | <p> | |
398 | Depends on the function where the error occurred | |
399 | </p> | |
400 | </td> | |
401 | </tr> | |
402 | </tbody> | |
403 | </table></div> | |
404 | <h6> | |
405 | <a name="math_toolkit.pol_ref.error_handling_policies.h4"></a> | |
406 | <span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.user_error"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.user_error">user_error</a> | |
407 | </h6> | |
408 | <p> | |
409 | Will call a user defined error handler: these are forward declared in boost/math/policies/error_handling.hpp, | |
410 | but the actual definitions must be provided by the user: | |
411 | </p> | |
412 | <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">math</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">policies</span><span class="special">{</span> | |
413 | ||
414 | <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> | |
415 | <span class="identifier">T</span> <span class="identifier">user_domain_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span> | |
416 | ||
417 | <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> | |
418 | <span class="identifier">T</span> <span class="identifier">user_pole_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span> | |
419 | ||
420 | <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> | |
421 | <span class="identifier">T</span> <span class="identifier">user_overflow_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span> | |
422 | ||
423 | <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> | |
424 | <span class="identifier">T</span> <span class="identifier">user_underflow_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span> | |
425 | ||
426 | <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> | |
427 | <span class="identifier">T</span> <span class="identifier">user_denorm_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span> | |
428 | ||
429 | <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> | |
430 | <span class="identifier">T</span> <span class="identifier">user_rounding_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span> | |
431 | ||
432 | <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> | |
433 | <span class="identifier">T</span> <span class="identifier">user_evaluation_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span> | |
434 | ||
435 | <span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">></span> | |
436 | <span class="identifier">T</span> <span class="identifier">user_indeterminate_result_error</span><span class="special">(</span><span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">function</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">message</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span><span class="special">&</span> <span class="identifier">val</span><span class="special">);</span> | |
437 | ||
438 | <span class="special">}}}</span> <span class="comment">// namespaces</span> | |
439 | </pre> | |
440 | <p> | |
441 | Note that the strings <span class="emphasis"><em>function</em></span> and <span class="emphasis"><em>message</em></span> | |
442 | may contain "%1%" format specifiers designed to be used in conjunction | |
443 | with Boost.Format. If these strings are to be presented to the program's | |
444 | end-user then the "%1%" format specifier should be replaced with | |
445 | the name of type T in the <span class="emphasis"><em>function</em></span> string, and if there | |
446 | is a %1% specifier in the <span class="emphasis"><em>message</em></span> string then it should | |
447 | be replaced with the value of <span class="emphasis"><em>val</em></span>. | |
448 | </p> | |
449 | <p> | |
450 | There is more information on user-defined error handlers in the <a class="link" href="../pol_tutorial/user_def_err_pol.html" title="Calling User Defined Error Handlers">tutorial | |
451 | here</a>. | |
452 | </p> | |
453 | <h5> | |
454 | <a name="math_toolkit.pol_ref.error_handling_policies.h5"></a> | |
455 | <span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.kinds_of_error_raised"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.kinds_of_error_raised">Kinds | |
456 | of Error Raised</a> | |
457 | </h5> | |
458 | <p> | |
459 | There are six kinds of error reported by this library, which are summarised | |
460 | in the following table: | |
461 | </p> | |
462 | <div class="informaltable"><table class="table"> | |
463 | <colgroup> | |
464 | <col> | |
465 | <col> | |
466 | <col> | |
467 | </colgroup> | |
468 | <thead><tr> | |
469 | <th> | |
470 | <p> | |
471 | Error Type | |
472 | </p> | |
473 | </th> | |
474 | <th> | |
475 | <p> | |
476 | Policy Class | |
477 | </p> | |
478 | </th> | |
479 | <th> | |
480 | <p> | |
481 | Description | |
482 | </p> | |
483 | </th> | |
484 | </tr></thead> | |
485 | <tbody> | |
486 | <tr> | |
487 | <td> | |
488 | <p> | |
489 | Domain Error | |
490 | </p> | |
491 | </td> | |
492 | <td> | |
493 | <p> | |
494 | boost::math::policies::domain_error<<span class="emphasis"><em>action</em></span>> | |
495 | </p> | |
496 | </td> | |
497 | <td> | |
498 | <p> | |
499 | Raised when more or more arguments are outside the defined range | |
500 | of the function. | |
501 | </p> | |
502 | <p> | |
503 | Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">domain_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code> | |
504 | </p> | |
505 | <p> | |
506 | When the action is set to <span class="emphasis"><em>throw_on_error</em></span> then | |
507 | throws <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">domain_error</span></code> | |
508 | </p> | |
509 | </td> | |
510 | </tr> | |
511 | <tr> | |
512 | <td> | |
513 | <p> | |
514 | Pole Error | |
515 | </p> | |
516 | </td> | |
517 | <td> | |
518 | <p> | |
519 | boost::math::policies::pole_error<<span class="emphasis"><em>action</em></span>> | |
520 | </p> | |
521 | </td> | |
522 | <td> | |
523 | <p> | |
524 | Raised when more or more arguments would cause the function to | |
525 | be evaluated at a pole. | |
526 | </p> | |
527 | <p> | |
528 | Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">pole_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code> | |
529 | </p> | |
530 | <p> | |
531 | When the action is <span class="emphasis"><em>throw_on_error</em></span> then throw | |
532 | a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">domain_error</span></code> | |
533 | </p> | |
534 | </td> | |
535 | </tr> | |
536 | <tr> | |
537 | <td> | |
538 | <p> | |
539 | Overflow Error | |
540 | </p> | |
541 | </td> | |
542 | <td> | |
543 | <p> | |
544 | boost::math::policies::overflow_error<<span class="emphasis"><em>action</em></span>> | |
545 | </p> | |
546 | </td> | |
547 | <td> | |
548 | <p> | |
549 | Raised when the result of the function is outside the representable | |
550 | range of the floating point type used. | |
551 | </p> | |
552 | <p> | |
553 | Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">overflow_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code>. | |
554 | </p> | |
555 | <p> | |
556 | When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws | |
557 | a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">overflow_error</span></code>. | |
558 | </p> | |
559 | </td> | |
560 | </tr> | |
561 | <tr> | |
562 | <td> | |
563 | <p> | |
564 | Underflow Error | |
565 | </p> | |
566 | </td> | |
567 | <td> | |
568 | <p> | |
569 | boost::math::policies::underflow_error<<span class="emphasis"><em>action</em></span>> | |
570 | </p> | |
571 | </td> | |
572 | <td> | |
573 | <p> | |
574 | Raised when the result of the function is too small to be represented | |
575 | in the floating point type used. | |
576 | </p> | |
577 | <p> | |
578 | Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">underflow_error</span><span class="special"><</span><span class="identifier">ignore_error</span><span class="special">></span></code> | |
579 | </p> | |
580 | <p> | |
581 | When the specified action is <span class="emphasis"><em>throw_on_error</em></span> | |
582 | then throws a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">underflow_error</span></code> | |
583 | </p> | |
584 | </td> | |
585 | </tr> | |
586 | <tr> | |
587 | <td> | |
588 | <p> | |
589 | Denorm Error | |
590 | </p> | |
591 | </td> | |
592 | <td> | |
593 | <p> | |
594 | boost::math::policies::denorm_error<<span class="emphasis"><em>action</em></span>> | |
595 | </p> | |
596 | </td> | |
597 | <td> | |
598 | <p> | |
599 | Raised when the result of the function is a denormalised value. | |
600 | </p> | |
601 | <p> | |
602 | Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">denorm_error</span><span class="special"><</span><span class="identifier">ignore_error</span><span class="special">></span></code> | |
603 | </p> | |
604 | <p> | |
605 | When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws | |
606 | a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">underflow_error</span></code> | |
607 | </p> | |
608 | </td> | |
609 | </tr> | |
610 | <tr> | |
611 | <td> | |
612 | <p> | |
613 | Rounding Error | |
614 | </p> | |
615 | </td> | |
616 | <td> | |
617 | <p> | |
618 | boost::math::policies::rounding_error<<span class="emphasis"><em>action</em></span>> | |
619 | </p> | |
620 | </td> | |
621 | <td> | |
622 | <p> | |
623 | Raised When one of the rounding functions <a class="link" href="../rounding/round.html" title="Rounding Functions">round</a>, | |
624 | <a class="link" href="../rounding/trunc.html" title="Truncation Functions">trunc</a> or <a class="link" href="../rounding/modf.html" title="Integer and Fractional Part Splitting (modf)">modf</a> is called with | |
625 | an argument that has no integer representation, or is too large | |
626 | to be represented in the result type | |
627 | </p> | |
628 | <p> | |
629 | Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">rounding_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code> | |
630 | </p> | |
631 | <p> | |
632 | When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws | |
633 | <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">rounding_error</span></code> | |
634 | </p> | |
635 | </td> | |
636 | </tr> | |
637 | <tr> | |
638 | <td> | |
639 | <p> | |
640 | Evaluation Error | |
641 | </p> | |
642 | </td> | |
643 | <td> | |
644 | <p> | |
645 | boost::math::policies::evaluation_error<<span class="emphasis"><em>action</em></span>> | |
646 | </p> | |
647 | </td> | |
648 | <td> | |
649 | <p> | |
650 | Raised when the result of the function is well defined and finite, | |
651 | but we were unable to compute it. Typically this occurs when an | |
652 | iterative method fails to converge. Of course ideally this error | |
653 | should never be raised: feel free to report it as a bug if it is! | |
654 | </p> | |
655 | <p> | |
656 | Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">evaluation_error</span><span class="special"><</span><span class="identifier">throw_on_error</span><span class="special">></span></code> | |
657 | </p> | |
658 | <p> | |
659 | When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws | |
660 | <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">evaluation_error</span></code> | |
661 | </p> | |
662 | </td> | |
663 | </tr> | |
664 | <tr> | |
665 | <td> | |
666 | <p> | |
667 | Indeterminate Result Error | |
668 | </p> | |
669 | </td> | |
670 | <td> | |
671 | <p> | |
672 | boost::math::policies::indeterminate_result_error<<span class="emphasis"><em>action</em></span>> | |
673 | </p> | |
674 | </td> | |
675 | <td> | |
676 | <p> | |
677 | Raised when the result of a function is not defined for the values | |
678 | that were passed to it. | |
679 | </p> | |
680 | <p> | |
681 | Defaults to <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">indeterminate_result_error</span><span class="special"><</span><span class="identifier">ignore_error</span><span class="special">></span></code> | |
682 | </p> | |
683 | <p> | |
684 | When the action is <span class="emphasis"><em>throw_on_error</em></span> then throws | |
685 | <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">domain_error</span></code> | |
686 | </p> | |
687 | </td> | |
688 | </tr> | |
689 | </tbody> | |
690 | </table></div> | |
691 | <h5> | |
692 | <a name="math_toolkit.pol_ref.error_handling_policies.h6"></a> | |
693 | <span class="phrase"><a name="math_toolkit.pol_ref.error_handling_policies.examples"></a></span><a class="link" href="error_handling_policies.html#math_toolkit.pol_ref.error_handling_policies.examples">Examples</a> | |
694 | </h5> | |
695 | <p> | |
696 | Suppose we want a call to <code class="computeroutput"><span class="identifier">tgamma</span></code> | |
697 | to behave in a C-compatible way and set global <code class="computeroutput"><span class="special">::</span><span class="identifier">errno</span></code> rather than throw an exception, we | |
698 | can achieve this at the call site using: | |
699 | </p> | |
700 | <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">special_functions</span><span class="special">/</span><span class="identifier">gamma</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> | |
701 | <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">tgamma</span><span class="special">;</span> | |
702 | ||
703 | <span class="comment">//using namespace boost::math::policies; may also be convenient.</span> | |
704 | <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">policy</span><span class="special">;</span> | |
705 | <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">evaluation_error</span><span class="special">;</span> | |
706 | <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">domain_error</span><span class="special">;</span> | |
707 | <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">overflow_error</span><span class="special">;</span> | |
708 | <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">domain_error</span><span class="special">;</span> | |
709 | <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">pole_error</span><span class="special">;</span> | |
710 | <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">::</span><span class="identifier">errno_on_error</span><span class="special">;</span> | |
711 | ||
712 | <span class="comment">// Define a policy:</span> | |
713 | <span class="keyword">typedef</span> <span class="identifier">policy</span><span class="special"><</span> | |
714 | <span class="identifier">domain_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>,</span> | |
715 | <span class="identifier">pole_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>,</span> | |
716 | <span class="identifier">overflow_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>,</span> | |
717 | <span class="identifier">evaluation_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">></span> | |
718 | <span class="special">></span> <span class="identifier">my_policy</span><span class="special">;</span> | |
719 | ||
720 | <span class="keyword">double</span> <span class="identifier">my_value</span> <span class="special">=</span> <span class="number">0.</span><span class="special">;</span> <span class="comment">// </span> | |
721 | ||
722 | <span class="comment">// Call the function applying my_policy:</span> | |
723 | <span class="keyword">double</span> <span class="identifier">t1</span> <span class="special">=</span> <span class="identifier">tgamma</span><span class="special">(</span><span class="identifier">my_value</span><span class="special">,</span> <span class="identifier">my_policy</span><span class="special">());</span> | |
724 | ||
725 | <span class="comment">// Alternatively (and equivalently) we could use helpful function</span> | |
726 | <span class="comment">// make_policy and define everything at the call site:</span> | |
727 | <span class="keyword">double</span> <span class="identifier">t2</span> <span class="special">=</span> <span class="identifier">tgamma</span><span class="special">(</span><span class="identifier">my_value</span><span class="special">,</span> | |
728 | <span class="identifier">make_policy</span><span class="special">(</span> | |
729 | <span class="identifier">domain_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>(),</span> | |
730 | <span class="identifier">pole_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>(),</span> | |
731 | <span class="identifier">overflow_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>(),</span> | |
732 | <span class="identifier">evaluation_error</span><span class="special"><</span><span class="identifier">errno_on_error</span><span class="special">>()</span> <span class="special">)</span> | |
733 | <span class="special">);</span> | |
734 | </pre> | |
735 | <p> | |
736 | Suppose we want a statistical distribution to return infinities, rather than | |
737 | throw exceptions, then we can use: | |
738 | </p> | |
739 | <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">math</span><span class="special">/</span><span class="identifier">distributions</span><span class="special">/</span><span class="identifier">normal</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> | |
740 | <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">normal_distribution</span><span class="special">;</span> | |
741 | ||
742 | <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">math</span><span class="special">::</span><span class="identifier">policies</span><span class="special">;</span> | |
743 | ||
744 | <span class="comment">// Define a specific policy:</span> | |
745 | <span class="keyword">typedef</span> <span class="identifier">policy</span><span class="special"><</span> | |
746 | <span class="identifier">overflow_error</span><span class="special"><</span><span class="identifier">ignore_error</span><span class="special">></span> | |
747 | <span class="special">></span> <span class="identifier">my_policy</span><span class="special">;</span> | |
748 | ||
749 | <span class="comment">// Define the distribution, using my_policy:</span> | |
750 | <span class="keyword">typedef</span> <span class="identifier">normal_distribution</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> <span class="identifier">my_policy</span><span class="special">></span> <span class="identifier">my_norm</span><span class="special">;</span> | |
751 | ||
752 | <span class="comment">// Construct a my_norm distribution, using default mean and standard deviation,</span> | |
753 | <span class="comment">// and get a 0.05 or 5% quantile:</span> | |
754 | <span class="keyword">double</span> <span class="identifier">q</span> <span class="special">=</span> <span class="identifier">quantile</span><span class="special">(</span><span class="identifier">my_norm</span><span class="special">(),</span> <span class="number">0.05</span><span class="special">);</span> <span class="comment">// = -1.64485</span> | |
755 | </pre> | |
756 | </div> | |
757 | <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> | |
758 | <td align="left"></td> | |
759 | <td align="right"><div class="copyright-footer">Copyright © 2006-2010, 2012-2014 Nikhar Agrawal, | |
760 | Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert | |
761 | Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan Råde, Gautam Sewani, | |
762 | Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang<p> | |
763 | Distributed under the Boost Software License, Version 1.0. (See accompanying | |
764 | file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) | |
765 | </p> | |
766 | </div></td> | |
767 | </tr></table> | |
768 | <hr> | |
769 | <div class="spirit-nav"> | |
770 | <a accesskey="p" href="../pol_ref.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../pol_ref.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="internal_promotion.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> | |
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773 | </html> |