Mercurial > octave-nkf

comparison libinterp/corefcn/inv.cc @ 18242:36057e2411f8 stable

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
test float rcond using float arithmetic in inv function (bug #41065) * inv.cc (Finv): Test float rcond using float arithmetic. Use correct rcond in warning message.
author John W. Eaton <jwe@octave.org>
date Tue, 07 Jan 2014 22:06:37 -0500
parents 175b392e91fe
children 9feb46ac6847
comparison
equal deleted inserted replaced
18241:450f50d3eb18 18242:36057e2411f8
211 if (nargout > 1) 211 if (nargout > 1)
212 retval(1) = isfloat ? octave_value (frcond) : octave_value (rcond); 212 retval(1) = isfloat ? octave_value (frcond) : octave_value (rcond);
213 213
214 retval(0) = result; 214 retval(0) = result;
215 215
216 volatile double xrcond = rcond; 216 bool rcond_plus_one_eq_one = false;
217 xrcond += 1.0; 217
218 if (nargout < 2 && (info == -1 || xrcond == 1.0)) 218 if (isfloat)
219 {
220 volatile float xrcond = frcond;
221 rcond_plus_one_eq_one = xrcond + 1.0F == 1.0F;
222 }
223 else
224 {
225 volatile double xrcond = rcond;
226 rcond_plus_one_eq_one = xrcond + 1.0 == 1.0;
227 }
228
229 if (nargout < 2 && (info == -1 || rcond_plus_one_eq_one))
219 warning ("inverse: matrix singular to machine precision, rcond = %g", 230 warning ("inverse: matrix singular to machine precision, rcond = %g",
220 rcond); 231 (isfloat ? frcond : rcond));
221 } 232 }
222 233
223 return retval; 234 return retval;
224 } 235 }
225 236
228 %!assert (inv (single ([1, 2; 3, 4])), single ([-2, 1; 1.5, -0.5]), sqrt (eps ("single"))) 239 %!assert (inv (single ([1, 2; 3, 4])), single ([-2, 1; 1.5, -0.5]), sqrt (eps ("single")))
229 240
230 %!error inv () 241 %!error inv ()
231 %!error inv ([1, 2; 3, 4], 2) 242 %!error inv ([1, 2; 3, 4], 2)
232 %!error <argument must be a square matrix> inv ([1, 2; 3, 4; 5, 6]) 243 %!error <argument must be a square matrix> inv ([1, 2; 3, 4; 5, 6])
244
245 %!test
246 %! [xinv, rcond] = inv (single ([1,2;3,4]));
247 %! assert (isa (xinv, 'single'));
248 %! assert (isa (rcond, 'single'));
249
250 %!test
251 %! [xinv, rcond] = inv ([1,2;3,4]);
252 %! assert (isa (xinv, 'double'));
253 %! assert (isa (rcond, 'double'));
233 */ 254 */
234 255
235 // FIXME: this should really be done with an alias, but 256 // FIXME: this should really be done with an alias, but
236 // alias_builtin() won't do the right thing if we are actually using 257 // alias_builtin() won't do the right thing if we are actually using
237 // dynamic linking. 258 // dynamic linking.