<div dir="ltr">Dear all,<div><br></div><div>I am trying to perform a magnetised TOV simulation using Einstein Toolkit and Spritz GRMHD code. In particular, currently I have a subroutine that adds a dipolar magnetic field to the TOV star after its initial data has been generated via TOVSolver thorn.</div><div>Within this subroutine, I have added the following lines that print the 'cctk_time' value as: </div><div><br></div><div>character(len=200) warnline<br>WRITE( warnline, '( "cctk_time: ", g16.7)' ) cctk_time<br>call CCTK_INFO(warnline)<br></div><div><br></div><div>This subroutine is scheduled in HydroBase_Con2Prim after Con2Prim step. And I get the following lines in the .out file as:</div><div>.........</div><div>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (TOVSolver): Integrated TOV equation</span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (TOVSolver): Information about the TOVs used:</span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (): TOV<span class="gmail-Apple-converted-space"> </span>radius<span class="gmail-Apple-converted-space"> </span>mass<span class="gmail-Apple-converted-space"> </span>bary_mass mass(g) cent.rho rho(cgi)<span class="gmail-Apple-converted-space"> </span>K <span class="gmail-Apple-converted-space"> </span>K(cgi)<span class="gmail-Apple-converted-space"> </span>Gamma</span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (): <span class="gmail-Apple-converted-space"> </span>1 <span class="gmail-Apple-converted-space"> </span>8.12502<span class="gmail-Apple-converted-space"> </span>1.40016<span class="gmail-Apple-converted-space"> </span>1.50618 2.78e+33<span class="gmail-Apple-converted-space"> </span>0.00128 7.92e+14<span class="gmail-Apple-converted-space"> </span>100 1.45e+05<span class="gmail-Apple-converted-space"> </span>2</span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (TOVSolver): Not using old matter initial data</span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (TOVSolver): Done interpolation.</span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time: <span class="gmail-Apple-converted-space"> </span>0.000000</span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): Adding a poloidal magnetic field to the TOV star on reflevel 0</span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): Adding atmo to the TOV star on reflevel = '0'</span></p>
<p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time: <span class="gmail-Apple-converted-space"> </span>0.000000</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">-----------------------------------------------------------------------------------------------------------------------------------</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">Iteration<span class="gmail-Apple-converted-space"> </span>Time |<span class="gmail-Apple-converted-space"> </span>ADMBASE::alp |<span class="gmail-Apple-converted-space"> </span>HYDROBASE::rho |<span class="gmail-Apple-converted-space"> </span>HYDROBASE::press |<span class="gmail-Apple-converted-space"> </span>SPRITZ::B_norm</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>|<span class="gmail-Apple-converted-space"> </span>minimum<span class="gmail-Apple-converted-space"> </span>maximum |<span class="gmail-Apple-converted-space"> </span>minimum<span class="gmail-Apple-converted-space"> </span>maximum |<span class="gmail-Apple-converted-space"> </span>minimum<span class="gmail-Apple-converted-space"> </span>maximum |<span class="gmail-Apple-converted-space"> </span>minimum<span class="gmail-Apple-converted-space"> </span>maximum</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">-----------------------------------------------------------------------------------------------------------------------------------</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>0 <span class="gmail-Apple-converted-space"> </span>0.000 |<span class="gmail-Apple-converted-space"> </span>0.6698612<span class="gmail-Apple-converted-space"> </span>0.9603815 | 5.827798e-11<span class="gmail-Apple-converted-space"> </span>0.0012800 |<span class="gmail-Apple-converted-space"> </span>0.0000000<span class="gmail-Apple-converted-space"> </span>0.0001638 | 8.399814e-09<span class="gmail-Apple-converted-space"> </span>0.0000399</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time:<span class="gmail-Apple-converted-space"> </span>0.3906250E-01</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time:<span class="gmail-Apple-converted-space"> </span>0.3906250E-01</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time:<span class="gmail-Apple-converted-space"> </span>0.7812500E-01</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time:<span class="gmail-Apple-converted-space"> </span>0.7812500E-01</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>1 <span class="gmail-Apple-converted-space"> </span>0.078 |<span class="gmail-Apple-converted-space"> </span>0.6698612<span class="gmail-Apple-converted-space"> </span>0.9603833 | 5.827814e-11<span class="gmail-Apple-converted-space"> </span>0.0012799 |<span class="gmail-Apple-converted-space"> </span>0.0000000<span class="gmail-Apple-converted-space"> </span>0.0001638 | 8.294987e-09<span class="gmail-Apple-converted-space"> </span>0.0000395</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time:<span class="gmail-Apple-converted-space"> </span>0.1171875</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time:<span class="gmail-Apple-converted-space"> </span>0.1171875</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time:<span class="gmail-Apple-converted-space"> </span>0.1562500</span></p><p class="gmail-p1" style="margin:0px;font:11px Menlo;color:rgb(0,0,0);background-color:rgb(255,255,255)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">INFO (Spritz_DipoleAndAtmo): cctk_time:<span class="gmail-Apple-converted-space"> </span>0.1562500</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">
</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>2 <span class="gmail-Apple-converted-space"> </span>0.156 |<span class="gmail-Apple-converted-space"> </span>0.6698612<span class="gmail-Apple-converted-space"> </span>0.9603850 | 5.827829e-11<span class="gmail-Apple-converted-space"> </span>0.0012797 |<span class="gmail-Apple-converted-space"> </span>0.0000000<span class="gmail-Apple-converted-space"> </span>0.0001638 | 8.294994e-09<span class="gmail-Apple-converted-space"> </span>0.0000390</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures">..........</span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><br></span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><br></span></p><p class="gmail-p1" style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><br></span></p><div>The simulation is performed in uniform grid with dx=dy=dz=0.3125, time::dtfac = 0.25 and HydroBase::timelevels = 2. </div></div><div>As you may see from the output lines, in between iteration 0 which is at cctk_time=0.0 and iteration 1 which is at cctk_time=0.078125, there is an intermediate time step with 'cctk_time=0.0390625' when the subroutine is called. </div><div><br></div><div>I was hoping to understand better why this intermediate time step exists between two consecutive iterations, and if there is any documentation I could look at. </div><div>Any help would be much appreciated.</div><div><br></div><div>Thank you very much.</div><div>Sincerely,</div><div>Jay Kalinani</div></div>