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</o:shapelayout></xml><![endif]--></head><body lang=DE link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Dear coin community,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>I detected several floating-point exceptions (</span><span lang=EN-US style='font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-language:DE'>FLTIV and FLTOV</span><span lang=EN-US>) in coin sources, components Clp, Cbc, Cgl, and CoinUtils. The exceptions occurred in some of my tests when checking for it by switching on these kind of exceptions with system call<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New"'> <b>feenableexcept(FE_DIVBYZERO | FE_OVERFLOW | FE_INVALID);<o:p></o:p></b></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Works with<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New"'>#define __USE_GNU 1<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New"'>#include <fenv.h><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New"'>#undef __USE_GNU<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>The listed examples already show a possible fix. It would be great if someone could look at these issues.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>In addition, a general approach of handling floating-point calculations would be great.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Kind regards<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Vitali<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=EN-US>Clp/src/ClpPackedMatrix::scale</span></b><span lang=EN-US> (around line 3599)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> // first if added to avoid float overflow<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> if (difference < 1.0e-4 || rowScale[iRow] < 1.0) { <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> double scaledDifference = difference * rowScale[iRow];<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> if (scaledDifference > tolerance && scaledDifference < 1.0e-4) {<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> // make gap larger<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> rowScale[iRow] *= 1.0e-4 / scaledDifference;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> rowScale[iRow] = CoinMax(1.0e-10, CoinMin(1.0e10, rowScale[iRow]));<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> }<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> }<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=EN-US>Cbc/src/CbcModel::analyzeObjective()</span></b><span lang=EN-US> (around line 595)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'>// added largestObj < smallestObj because smallest was already infinity<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'>else if ((largestObj < smallestObj || largestObj < smallestObj*5.0) && <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> !parentModel_ &&<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> !numberContinuousObj &&<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> !numberGeneralIntegerObj &&<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> numberIntegerObj*2 < CoinMin(numberColumns,20)) <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=EN-US>Cbc/src/CbcModel::solveWithCuts()</span></b><span lang=EN-US> (around line 9354) <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> // added divisor since static_cast<double> (numberActiveGenerators - 1) was 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> if (divisor == 0.0)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> divisor = 0.00001;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> smallProblem = (0.2 * (totalCuts - generator_[i]->numberCutsInTotal())) /<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> divisor ;<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=EN-US>Cbc/src/CbcHeuristic::CbcRounding::solution</span></b><span lang=EN-US> (around line 2462)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> // distance was infinity, gap negative -> added gap + distance > 0.0 ||<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> if (gap + distance > 0.0 || gap + value*distance > 0.0)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> distance = -gap / value;<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=EN-US>Cgl/src/CglPreProcess.cpp::preProcessNonDefault</span></b><span lang=EN-US> (around line 1722)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> // check for +COIN_DBL_MAX<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> if (upperValue < COIN_DBL_MAX) {<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> iUpper = static_cast<int> (floor(upperValue+1.0e-5));<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> }<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> int iLower = -COIN_INT_MAX;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> // check for -COIN_DBL_MAX<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> if (lowerValue > -COIN_DBL_MAX) {<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> iLower = static_cast<int> (ceil(lowerValue-1.0e-5));<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> }<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=EN-US>Cgl/src/CglTwomir.cpp::DGG_add2stepToList</span></b><span lang=EN-US> (around line 1782)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> // added if because cut->rhs was 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> if (cut->rhs > 1E-6 || cut->rhs < -1E-6)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> norm_val /= cut->rhs * cut->rhs;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span lang=EN-US>CoinUtils/src/CoinPresolveDual.cpp::remove_dual_action::presolve</span></b><span lang=EN-US> (around line 595) <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> // rephrased computation of mindelta and maxdelta<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> double mindelta = ymin[i] ;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> if (ymin[i] > -COIN_DBL_MAX || (aij <= 1.0 && aij >= -1.0)){<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> mindelta = aij*ymin[i] ;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> }<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> double maxdelta = ymax[i] ;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> if (ymax[i] < COIN_DBL_MAX || (aij <= 1.0 && aij >= -1.0)){<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> maxdelta = aij*ymax[i] ;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Courier New";mso-fareast-language:DE'> }<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>