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From: |
Axel Kohlmeyer <akohlmey@...24...> |

Date: |
Thu, 27 Jul 2017 15:51:50 -0400 |

>> variable displace equal "v_L0 + (0.5*v_L0)*(1 + >> (2/PI)*asin(sin((2*PI*(1/v_Tp)*step*dt) - (PI/2))))" >> variable rate equal "(2*v_L0*(1/v_Tp))*(-1)^floor(2*(1/v_Tp)*step*dt)" >> fix 4 all deform 1 x variable v_displace v_rate remap v >> >> >> However, I obtained an error statement: ERROR: Power by 0 in variable >> formula (../variable.cpp:1718) >> >> Even when I looked at the LAMMPS error manual, I am not understanding this >> error since my variable formula does not have a zero powered to a number. I > > that is not what the error message says. it says that you have a > number raised to the power of 0. that said, LAMMPS should not stop with an error here. x^0 should always result in 1.0 for any value of x, even for x == NaN. instead 0^y with y < 0.0 should be disallowed, as this is equivalent to 1.0/0^-y and thus would cause a division by zero. so the current behavior of LAMMPS is actually a bug. axel > > axel. > -- Dr. Axel Kohlmeyer akohlmey@...24... http://goo.gl/1wk0 College of Science & Technology, Temple University, Philadelphia PA, USA International Centre for Theoretical Physics, Trieste. Italy.

**Follow-Ups**:**Re: [lammps-users] Inquiry on LAMMPS fix_deform and variable formula"***From:*MASATO KOIZUMI <mkoizumi@...3709...>

**References**:**Re: [lammps-users] Inquiry on LAMMPS fix_deform and variable formula"***From:*MASATO KOIZUMI <mkoizumi@...3709...>

**Re: [lammps-users] Inquiry on LAMMPS fix_deform and variable formula"***From:*Axel Kohlmeyer <akohlmey@...24...>

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