<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hello Luis,<div><br></div><div>I agree with your solution here. It seems much better to use a specific methods to solve the equation where the erroneous or unstable conditions can be better explicitly handled. </div><div><br></div><div>However, I am still left with the question what is causing the the compiler error. Is this a real problem in VNL? I suppose we really are not specifically testing vnl, so we can program around these issues.</div><div> </div><div>Brad</div><div><br></div><div><div>On Apr 29, 2010, at 6:08 PM, Luis Ibanez wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><br>The compilation problem that the (previously untested)<br>NonUniformBSpline class is displaying in many platforms:<br><br><a href="http://public.kitware.com/dashboard.php?name=itk">http://public.kitware.com/dashboard.php?name=itk</a><br>
<br><br>arises from the expression in line 313:<br><br>The following code:<br><br> vnl_matrix<double> B = <br> vnl_matrix_inverse<double>( N_matrix.transpose() * N_matrix) * N_matrix.transpose() * data_matrix;<br>
<br><br><div id=":8t" class="ii gt">is trying to solve the linear system<br><br> X = N * B<br><br>by doing:<br><br> B = ( N' * N )^-1 * N' * X<br></div><br>This could be better done by using of <br>
of the linear solvers in VXL. For example<br>the LSQR one that was fixed recently.<br><br><br>So, the suggested plan to solve this<br>compilation problem is to replace that<br>line 313 with a call to the vnl linear <br>system class and then to the vnl_lsqr<br>
solver.<br><br>This should be happening later today...<br><br><br> Luis<br><br><br>
<span><ATT00001..txt></span></blockquote></div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><p style="margin: 0.0px 0.0px 0.0px 0.0px"><font face="Helvetica" size="3" style="font: 12.0px Helvetica">========================================================</font></p><p style="margin: 0.0px 0.0px 0.0px 0.0px"><font face="Helvetica" size="3" style="font: 12.0px Helvetica">Bradley Lowekamp<span class="Apple-converted-space"> </span><span class="Apple-converted-space"> </span></font></p><p style="margin: 0.0px 0.0px 0.0px 0.0px"><font class="Apple-style-span" face="Arial"><span class="Apple-style-span" style="font-family: Arial; "><span class="Apple-style-span" style="font-family: Arial; ">Lockheed Martin </span></span></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">Contractor for</font></p><p style="margin: 0.0px 0.0px 0.0px 0.0px"><font face="Helvetica" size="3" style="font: 12.0px Helvetica">Office of High Performance Computing and Communications</font></p><p style="margin: 0.0px 0.0px 0.0px 0.0px"><font face="Helvetica" size="3" style="font: 12.0px Helvetica">National Library of Medicine<span class="Apple-converted-space"> </span></font></p><p style="margin: 0.0px 0.0px 0.0px 0.0px"><font face="Helvetica" size="3" style="font: 12.0px Helvetica"><a href="mailto:blowekamp@mail.nih.gov">blowekamp@mail.nih.gov</a></font></p><br class="Apple-interchange-newline"></span></span>
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