4 deleted 17 characters in body edited Oct 26 '12 at 11:02 Ajasja 9,86422 gold badges3838 silver badges9797 bronze badges I'm using ParallelTable[] to calculate a function over a range of my parameters , ($$\omega,\ell$$). This seems to be working well (in terms of speed increase) except for some strange Precision issues. I set the $MinPrecision=40 at the start of the notebook as well as my working precision, precision goal and accuracy goal for some computations later in the notebook as  wp=$$MinPrecision; ac=$$MinPrecision-8; pg=wp/2;  The rest of my code basically defines some helper functions before going on to the main function (that I feed into ParallelTablParallelTable). This main function uses the helper functions along with NDSolve and NIntegrate to do some computations, and it's in these that I feed the Working Precision->wp ,AccuracyGoal->ac, PrecisionGoal->pg. I have used DistrubuteDefinitionsDistributeDefinitions on all my variables, helper functions, and the main function, and even on $MinPrecision, also all my initial conditions for NDSolve have N[...,wp] wrapped around them, but still when I use ParallelTable[...] I get errors:  Precision::precsm. Requested precision 39.153977328439204 is smaller than $MinPrecision.  I don't get any such error when I simply use Do[...] or Table[..] on my main function, and indeed the results differ at the 33rd decimal place, which is the decimal the above number is precision too. I have no idea what this number is unfortunately, it doesn't look like any of my outputs or inputs. I just don't understand how this could not crop up with the non-parallelized forms, but crop up with parallelized? Minimal Example This is much simpler than my code, but I think it still captures it and the problem: Definitions: M = 1; $$MinPrecision = 40; wp =$$MinPrecision; ac =$MinPrecision - 8; pg = wp/2; rinf = 15000;  The main function to be parallelized: dGenBessE[\[Omega]_?NumericQ, l_?IntegerQ] := Block[{\[CapitalPhi]out, init, dinit}, init = 0.00006630728036817007679447778124486601253323 + 6.913102762021489976135937610105907096265*10^-6 I; dinit = -6.958226432502243329110910813935678705519*10^-7 + 6.631148430876236565520382557577187147081*10^-6 I; \[CapitalPhi]out[\[Omega], l] = \[CapitalPhi] /. Block[{$$MaxExtraPrecision = 100}, NDSolve[{\[CapitalPhi]''[r] + (2 (r - M))/( r (r - 2 M)) \[CapitalPhi]'[ r] + ((\[Omega]^2 r^2)/(r - 2 M)^2 - (l (l + 1))/( r (r - 2 M))) \[CapitalPhi][r] == 0, \[CapitalPhi][rinf] == N[init, wp], \[CapitalPhi]'[rinf] == N[dinit, wp]}, \[CapitalPhi], {r, 30, 40}, WorkingPrecision -> wp, AccuracyGoal -> ac, PrecisionGoal -> pg, MaxSteps -> \[Infinity]]][[1]]; Print["For \[Omega]=", \[Omega], " and l=", l, ": "]; Print["Kernel ID: ",$$KernelID]; Print["Precision of init: ", Precision[init]]; Print["Precision of dinit: ", Precision[dinit]]; Print["\[CapitalPhi]out at 35=" , N[\[CapitalPhi]out[\[Omega], l][35], wp] ]; Print["Precision of \[CapitalPhi]out: ", Precision[\[CapitalPhi]out[\[Omega], l][35]]]; ]  ] Do Paralleization prereqs: LaunchKernels[4] DistributeDefinitions[M, rinf, wp, ac, pg, $MinPrecision,dGenBessE];  Attempt to run it with Paralleize for two different values: Parallelize[{dGenBessE[1/10, 0], dGenBessE[1/10, 1]}] // AbsoluteTiming  Result For me this leads to a Precision::precsm: Requested precision 38.95475956978393 is smaller than $$MinPrecision. Using$$MinPrecision instead.  I'm using ParallelTable[] to calculate a function over a range of my parameters , ($$\omega,\ell$$). This seems to be working well (in terms of speed increase) except for some strange Precision issues. I set the $MinPrecision=40 at the start of the notebook as well as my working precision, precision goal and accuracy goal for some computations later in the notebook as  wp=$$MinPrecision; ac=$$MinPrecision-8; pg=wp/2;  The rest of my code basically defines some helper functions before going on to the main function (that I feed into ParallelTabl). This main function uses the helper functions along with NDSolve and NIntegrate to do some computations, and it's in these that I feed the Working Precision->wp ,AccuracyGoal->ac, PrecisionGoal->pg. I have used DistrubuteDefinitions on all my variables, helper functions, and the main function, and even on $MinPrecision, also all my initial conditions for NDSolve have N[...,wp] wrapped around them, but still when I use ParallelTable[...] I get errors:  Precision::precsm. Requested precision 39.153977328439204 is smaller than$MinPrecision.  I don't get any such error when I simply use Do[...] or Table[..] on my main function, and indeed the results differ at the 33rd decimal place, which is the decimal the above number is precision too. I have no idea what this number is unfortunately, it doesn't look like any of my outputs or inputs. I just don't understand how this could not crop up with the non-parallelized forms, but crop up with parallelized? Minimal Example This is much simpler than my code, but I think it still captures it and the problem: Definitions: M = 1; $$MinPrecision = 40; wp =$$MinPrecision; ac = $MinPrecision - 8; pg = wp/2; rinf = 15000;  The main function to be parallelized: dGenBessE[\[Omega]_?NumericQ, l_?IntegerQ] := Block[{\[CapitalPhi]out, init, dinit}, init = 0.00006630728036817007679447778124486601253323 + 6.913102762021489976135937610105907096265*10^-6 I; dinit = -6.958226432502243329110910813935678705519*10^-7 + 6.631148430876236565520382557577187147081*10^-6 I; \[CapitalPhi]out[\[Omega], l] = \[CapitalPhi] /. Block[{$$MaxExtraPrecision = 100}, NDSolve[{\[CapitalPhi]''[r] + (2 (r - M))/( r (r - 2 M)) \[CapitalPhi]'[ r] + ((\[Omega]^2 r^2)/(r - 2 M)^2 - (l (l + 1))/( r (r - 2 M))) \[CapitalPhi][r] == 0, \[CapitalPhi][rinf] == N[init, wp], \[CapitalPhi]'[rinf] == N[dinit, wp]}, \[CapitalPhi], {r, 30, 40}, WorkingPrecision -> wp, AccuracyGoal -> ac, PrecisionGoal -> pg, MaxSteps -> \[Infinity]]][[1]]; Print["For \[Omega]=", \[Omega], " and l=", l, ": "]; Print["Kernel ID: ",$$KernelID]; Print["Precision of init: ", Precision[init]]; Print["Precision of dinit: ", Precision[dinit]]; Print["\[CapitalPhi]out at 35=" , N[\[CapitalPhi]out[\[Omega], l][35], wp] ]; Print["Precision of \[CapitalPhi]out: ", Precision[\[CapitalPhi]out[\[Omega], l][35]]];  ] Do Paralleization prereqs: LaunchKernels[4] DistributeDefinitions[M, rinf, wp, ac, pg,$MinPrecision,dGenBessE];  Attempt to run it with Paralleize for two different values: Parallelize[{dGenBessE[1/10, 0], dGenBessE[1/10, 1]}] // AbsoluteTiming  Result For me this leads to a Precision::precsm: Requested precision 38.95475956978393 is smaller than $$MinPrecision. Using$$MinPrecision instead.  I'm using ParallelTable[] to calculate a function over a range of my parameters , ($$\omega,\ell$$). This seems to be working well (in terms of speed increase) except for some strange Precision issues. I set the $MinPrecision=40 at the start of the notebook as well as my working precision, precision goal and accuracy goal for some computations later in the notebook as  wp=$$MinPrecision; ac=$$MinPrecision-8; pg=wp/2;  The rest of my code basically defines some helper functions before going on to the main function (that I feed into ParallelTable). This main function uses the helper functions along with NDSolve and NIntegrate to do some computations, and it's in these that I feed the Working Precision->wp ,AccuracyGoal->ac, PrecisionGoal->pg. I have used DistributeDefinitions on all my variables, helper functions, and the main function, and even on $MinPrecision, also all my initial conditions for NDSolve have N[...,wp] wrapped around them, but still when I use ParallelTable[...] I get errors:  Precision::precsm. Requested precision 39.153977328439204 is smaller than $MinPrecision.  I don't get any such error when I simply use Do[...] or Table[..] on my main function, and indeed the results differ at the 33rd decimal place, which is the decimal the above number is precision too. I have no idea what this number is unfortunately, it doesn't look like any of my outputs or inputs. I just don't understand how this could not crop up with the non-parallelized forms, but crop up with parallelized? Minimal Example This is much simpler than my code, but I think it still captures it and the problem: Definitions: M = 1; $$MinPrecision = 40; wp =$$MinPrecision; ac =$MinPrecision - 8; pg = wp/2; rinf = 15000;  The main function to be parallelized: dGenBessE[\[Omega]_?NumericQ, l_?IntegerQ] := Block[{\[CapitalPhi]out, init, dinit}, init = 0.00006630728036817007679447778124486601253323 + 6.913102762021489976135937610105907096265*10^-6 I; dinit = -6.958226432502243329110910813935678705519*10^-7 + 6.631148430876236565520382557577187147081*10^-6 I; \[CapitalPhi]out[\[Omega], l] = \[CapitalPhi] /. Block[{$$MaxExtraPrecision = 100}, NDSolve[{\[CapitalPhi]''[r] + (2 (r - M))/( r (r - 2 M)) \[CapitalPhi]'[ r] + ((\[Omega]^2 r^2)/(r - 2 M)^2 - (l (l + 1))/( r (r - 2 M))) \[CapitalPhi][r] == 0, \[CapitalPhi][rinf] == N[init, wp], \[CapitalPhi]'[rinf] == N[dinit, wp]}, \[CapitalPhi], {r, 30, 40}, WorkingPrecision -> wp, AccuracyGoal -> ac, PrecisionGoal -> pg, MaxSteps -> \[Infinity]]][[1]]; Print["For \[Omega]=", \[Omega], " and l=", l, ": "]; Print["Kernel ID: ",$$KernelID]; Print["Precision of init: ", Precision[init]]; Print["Precision of dinit: ", Precision[dinit]]; Print["\[CapitalPhi]out at 35=" , N[\[CapitalPhi]out[\[Omega], l][35], wp] ]; Print["Precision of \[CapitalPhi]out: ", Precision[\[CapitalPhi]out[\[Omega], l][35]]]; ]  Do Paralleization prereqs: LaunchKernels[4] DistributeDefinitions[M, rinf, wp, ac, pg, $MinPrecision,dGenBessE];  Attempt to run it with Paralleize for two different values: Parallelize[{dGenBessE[1/10, 0], dGenBessE[1/10, 1]}] // AbsoluteTiming  Result For me this leads to a Precision::precsm: Requested precision 38.95475956978393 is smaller than $$MinPrecision. Using$$MinPrecision instead.  3 added 2045 characters in body edited Oct 26 '12 at 9:59 fpghost 91511 gold badge1111 silver badges2121 bronze badges I'm using ParallelTable[] to calculate a function over a range of my parameters , ($$\omega,\ell$$). This seems to be working well (in terms of speed increase) except for some strange Precision issues. I set the $MinPrecision=40 at the start of the notebook as well as my working precision, precision goal and accuracy goal for some computations later in the notebook as  wp=$$MinPrecision; ac=$$MinPrecision-8; pg=wp/2;  The rest of my code basically defines some helper functions before going on to the main function (that I feed into ParallelTabl). This main function uses the helper functions along with NDSolve and NIntegrate to do some computations, and it's in these that I feed the Working Precision->wp ,AccuracyGoal->ac, PrecisionGoal->pg. I have used DistrubuteDefinitions on all my variables, helper functions, and the main function, and even on $MinPrecision, also all my initial conditions for NDSolve have N[...,wp] wrapped around them, but still when I use ParallelTable[...] I get errors:  Precision::precsm. Requested precision 39.153977328439204 is smaller than$MinPrecision.  I don't get any such error when I simply use Do[...] or Table[..] on my main function, and indeed the results differ at the 33rd decimal place, which is the decimal the above number is precision too. I have no idea what this number is unfortunately, it doesn't look like any of my outputs or inputs. I just don't understand how this could not crop up with the non-parallelized forms, but crop up with parallelized? Minimal Example This is much simpler than my code, but I think it still captures it and the problem: Definitions: M = 1; $$MinPrecision = 40; wp =$$MinPrecision; ac = $MinPrecision - 8; pg = wp/2; rinf = 15000;  The main function to be parallelized: dGenBessE[\[Omega]_?NumericQ, l_?IntegerQ] := Block[{\[CapitalPhi]out, init, dinit}, init = 0.00006630728036817007679447778124486601253323 + 6.913102762021489976135937610105907096265*10^-6 I; dinit = -6.958226432502243329110910813935678705519*10^-7 + 6.631148430876236565520382557577187147081*10^-6 I; \[CapitalPhi]out[\[Omega], l] = \[CapitalPhi] /. Block[{$$MaxExtraPrecision = 100}, NDSolve[{\[CapitalPhi]''[r] + (2 (r - M))/( r (r - 2 M)) \[CapitalPhi]'[ r] + ((\[Omega]^2 r^2)/(r - 2 M)^2 - (l (l + 1))/( r (r - 2 M))) \[CapitalPhi][r] == 0, \[CapitalPhi][rinf] == N[init, wp], \[CapitalPhi]'[rinf] == N[dinit, wp]}, \[CapitalPhi], {r, 30, 40}, WorkingPrecision -> wp, AccuracyGoal -> ac, PrecisionGoal -> pg, MaxSteps -> \[Infinity]]][[1]]; Print["For \[Omega]=", \[Omega], " and l=", l, ": "]; Print["Kernel ID: ",$$KernelID]; Print["Precision of init: ", Precision[init]]; Print["Precision of dinit: ", Precision[dinit]]; Print["\[CapitalPhi]out at 35=" , N[\[CapitalPhi]out[\[Omega], l][35], wp] ]; Print["Precision of \[CapitalPhi]out: ", Precision[\[CapitalPhi]out[\[Omega], l][35]]];  ] Do Paralleization prereqs: LaunchKernels[4] DistributeDefinitions[M, rinf, wp, ac, pg,$MinPrecision,dGenBessE];  Attempt to run it with Paralleize for two different values: Parallelize[{dGenBessE[1/10, 0], dGenBessE[1/10, 1]}] // AbsoluteTiming  Result For me this leads to a Precision::precsm: Requested precision 38.95475956978393 is smaller than $$MinPrecision. Using$$MinPrecision instead.  I'm using ParallelTable[] to calculate a function over a range of my parameters , ($$\omega,\ell$$). This seems to be working well (in terms of speed increase) except for some strange Precision issues. I set the $MinPrecision=40 at the start of the notebook as well as my working precision, precision goal and accuracy goal for some computations later in the notebook as  wp=$$MinPrecision; ac=$$MinPrecision-8; pg=wp/2;  The rest of my code basically defines some helper functions before going on to the main function (that I feed into ParallelTabl). This main function uses the helper functions along with NDSolve and NIntegrate to do some computations, and it's in these that I feed the Working Precision->wp ,AccuracyGoal->ac, PrecisionGoal->pg. I have used DistrubuteDefinitions on all my variables, helper functions, and the main function, and even on $MinPrecision, also all my initial conditions for NDSolve have N[...,wp] wrapped around them, but still when I use ParallelTable[...] I get errors:  Precision::precsm. Requested precision 39.153977328439204 is smaller than $MinPrecision.  I don't get any such error when I simply use Do[...] or Table[..] on my main function, and indeed the results differ at the 33rd decimal place, which is the decimal the above number is precision too. I have no idea what this number is unfortunately, it doesn't look like any of my outputs or inputs. I just don't understand how this could not crop up with the non-parallelized forms, but crop up with parallelized? I'm using ParallelTable[] to calculate a function over a range of my parameters , ($$\omega,\ell$$). This seems to be working well (in terms of speed increase) except for some strange Precision issues. I set the $MinPrecision=40 at the start of the notebook as well as my working precision, precision goal and accuracy goal for some computations later in the notebook as  wp=$$MinPrecision; ac=$$MinPrecision-8; pg=wp/2;  The rest of my code basically defines some helper functions before going on to the main function (that I feed into ParallelTabl). This main function uses the helper functions along with NDSolve and NIntegrate to do some computations, and it's in these that I feed the Working Precision->wp ,AccuracyGoal->ac, PrecisionGoal->pg. I have used DistrubuteDefinitions on all my variables, helper functions, and the main function, and even on $MinPrecision, also all my initial conditions for NDSolve have N[...,wp] wrapped around them, but still when I use ParallelTable[...] I get errors:  Precision::precsm. Requested precision 39.153977328439204 is smaller than$MinPrecision.  I don't get any such error when I simply use Do[...] or Table[..] on my main function, and indeed the results differ at the 33rd decimal place, which is the decimal the above number is precision too. I have no idea what this number is unfortunately, it doesn't look like any of my outputs or inputs. I just don't understand how this could not crop up with the non-parallelized forms, but crop up with parallelized? Minimal Example This is much simpler than my code, but I think it still captures it and the problem: Definitions: M = 1; $$MinPrecision = 40; wp =$$MinPrecision; ac = $MinPrecision - 8; pg = wp/2; rinf = 15000;  The main function to be parallelized: dGenBessE[\[Omega]_?NumericQ, l_?IntegerQ] := Block[{\[CapitalPhi]out, init, dinit}, init = 0.00006630728036817007679447778124486601253323 + 6.913102762021489976135937610105907096265*10^-6 I; dinit = -6.958226432502243329110910813935678705519*10^-7 + 6.631148430876236565520382557577187147081*10^-6 I; \[CapitalPhi]out[\[Omega], l] = \[CapitalPhi] /. Block[{$$MaxExtraPrecision = 100}, NDSolve[{\[CapitalPhi]''[r] + (2 (r - M))/( r (r - 2 M)) \[CapitalPhi]'[ r] + ((\[Omega]^2 r^2)/(r - 2 M)^2 - (l (l + 1))/( r (r - 2 M))) \[CapitalPhi][r] == 0, \[CapitalPhi][rinf] == N[init, wp], \[CapitalPhi]'[rinf] == N[dinit, wp]}, \[CapitalPhi], {r, 30, 40}, WorkingPrecision -> wp, AccuracyGoal -> ac, PrecisionGoal -> pg, MaxSteps -> \[Infinity]]][[1]]; Print["For \[Omega]=", \[Omega], " and l=", l, ": "]; Print["Kernel ID: ",$$KernelID]; Print["Precision of init: ", Precision[init]]; Print["Precision of dinit: ", Precision[dinit]]; Print["\[CapitalPhi]out at 35=" , N[\[CapitalPhi]out[\[Omega], l][35], wp] ]; Print["Precision of \[CapitalPhi]out: ", Precision[\[CapitalPhi]out[\[Omega], l][35]]];  ] Do Paralleization prereqs: LaunchKernels[4] DistributeDefinitions[M, rinf, wp, ac, pg,$MinPrecision,dGenBessE];  Attempt to run it with Paralleize for two different values: Parallelize[{dGenBessE[1/10, 0], dGenBessE[1/10, 1]}] // AbsoluteTiming  Result For me this leads to a Precision::precsm: Requested precision 38.95475956978393 is smaller than $$MinPrecision. Using$$MinPrecision instead.  2 added 11 characters in body edited Oct 26 '12 at 9:08 fpghost 91511 gold badge1111 silver badges2121 bronze badges I'm using ParallelTableParallelTable[] to calculate a function over a range of my parameters , ($$\omega,\ell$$). This seems to be working well (in terms of speed increase) except for some strange Precision issues. I set the $MinPrecision=40$MinPrecision=40 at the start of the notebook as well as my working precision, precision goal and accuracy goal for some computations later in the notebook as  wp=$$MinPrecision; ac=$$$$MinPrecision; ac=$$MinPrecision-8; pg=wp/2;  The rest of my code basically defines some helper functions before going on to the main function (that I feed into ParallelTableParallelTabl). This main function uses the helper functions along with NDSolveNDSolve and NIntegrateNIntegrate to do some computations, and it's in these that I feed the Working Precision->wp ,AccuracyGoal->ac, PrecisionGoal->pg. I have used DistrubuteDefinitions on all my variables, helper functions, and the main function, and even on $MinPrecision, also all my initial conditions for NDSolve have N[...,wp] wrapped around them, but still when I use ParallelTable[...] I get errors:  Precision::precsm. Requested precision 39.153977328439204 is smaller than$MinPrecision.  I don't get any such error when I simply use Do[...] or Talbe[Table[..] on my main function, and indeed the results differ at the 33rd decimal place, which is the decimal the above number is precision too. I have no idea what this number is unfortunately, it doesn't look like any of my outputs or inputs. I just don't understand how this could not crop up with the non-parallelized forms, but crop up with parallelized? I'm using ParallelTable to calculate a function over a range of my parameters , ($$\omega,\ell$$). This seems to be working well (in terms of speed increase) except for some strange Precision issues. I set the $MinPrecision=40 at the start of the notebook as well as my working precision, precision goal and accuracy goal for some computations later in the notebook as  wp=$$MinPrecision; ac=$$MinPrecision-8; pg=wp/2;  The rest of my code basically defines some helper functions before going on to the main function (that I feed into ParallelTable). This main function uses the helper functions along with NDSolve and NIntegrate to do some computations, and it's in these that I feed the Working Precision->wp ,AccuracyGoal->ac, PrecisionGoal->pg. I have used DistrubuteDefinitions on all my variables, helper functions, and the main function, and even on $MinPrecision, also all my initial conditions for NDSolve have N[...,wp] wrapped around them, but still when I use ParallelTable[...] I get errors:  Precision::precsm. Requested precision 39.153977328439204 is smaller than $MinPrecision.  I don't get any such error when I simply use Do[...] or Talbe[..] on my main function, and indeed the results differ at the 33rd decimal place, which is the decimal the above number is precision too. I have no idea what this number is unfortunately, it doesn't look like any of my outputs or inputs. I just don't understand how this could not crop up with the non-parallelized forms, but crop up with parallelized? I'm using ParallelTable[] to calculate a function over a range of my parameters , ($$\omega,\ell$$). This seems to be working well (in terms of speed increase) except for some strange Precision issues. I set the $MinPrecision=40 at the start of the notebook as well as my working precision, precision goal and accuracy goal for some computations later in the notebook as  wp=$$MinPrecision; ac=$$MinPrecision-8; pg=wp/2;  The rest of my code basically defines some helper functions before going on to the main function (that I feed into ParallelTabl). This main function uses the helper functions along with NDSolve and NIntegrate to do some computations, and it's in these that I feed the Working Precision->wp ,AccuracyGoal->ac, PrecisionGoal->pg. I have used DistrubuteDefinitions on all my variables, helper functions, and the main function, and even on $MinPrecision, also all my initial conditions for NDSolve have N[...,wp] wrapped around them, but still when I use ParallelTable[...] I get errors:  Precision::precsm. Requested precision 39.153977328439204 is smaller than$MinPrecision.  I don't get any such error when I simply use Do[...] or Table[..] on my main function, and indeed the results differ at the 33rd decimal place, which is the decimal the above number is precision too. I have no idea what this number is unfortunately, it doesn't look like any of my outputs or inputs. I just don't understand how this could not crop up with the non-parallelized forms, but crop up with parallelized? 1 asked Oct 26 '12 at 8:47 fpghost 91511 gold badge1111 silver badges2121 bronze badges