https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/How-to-improve-accuracy-of-solution-given-by-mkl-PARDISO/m-p/828989#M5384 <P>but it might be not help in the case of ill-conditioned matrices</P> Tue, 04 May 2010 09:51:54 GMT Gennady_F_Intel 2010-05-04T09:51:54Z https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/How-to-improve-accuracy-of-solution-given-by-mkl-PARDISO/m-p/828987#M5382 Dear all,<BR />I am using mkl PARDISO to solve A*x=b with default parameters iparm(1)=0.<BR />From solution x1 given by PARDISO, I compute b1= A*x1. Norm of error (b1-b) is about 1E-2. Do you know how to improve this error more, for example 1E-6?<BR />Thanks<BR />Thanh Sat, 01 May 2010 14:07:14 GMT https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/How-to-improve-accuracy-of-solution-given-by-mkl-PARDISO/m-p/828987#M5382 chdthanh 2010-05-01T14:07:14Z https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/How-to-improve-accuracy-of-solution-given-by-mkl-PARDISO/m-p/828988#M5383 <P>Dear, Thanh, <BR />please, set iparm() manually (iparm(1)=1). Try to use iterative refinement step - iparm(8)=1. iparm(8) should be set to the maximum number of iterative refinement steps that the solver will perform. </P> Tue, 04 May 2010 05:38:41 GMT https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/How-to-improve-accuracy-of-solution-given-by-mkl-PARDISO/m-p/828988#M5383 Sergey_Solovev__Inte 2010-05-04T05:38:41Z https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/How-to-improve-accuracy-of-solution-given-by-mkl-PARDISO/m-p/828989#M5384 <P>but it might be not help in the case of ill-conditioned matrices</P> Tue, 04 May 2010 09:51:54 GMT https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/How-to-improve-accuracy-of-solution-given-by-mkl-PARDISO/m-p/828989#M5384 Gennady_F_Intel 2010-05-04T09:51:54Z