From 74854155dd48e9c507e2278f381e1d4ca84ea87f Mon Sep 17 00:00:00 2001 From: sjplimp Date: Wed, 20 Feb 2008 15:00:04 +0000 Subject: [PATCH] git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@1546 f3b2605a-c512-4ea7-a41b-209d697bcdaa --- doc/Section_commands.html | 2 +- doc/compute.html | 2 +- doc/compute_reduce.html | 106 ++++++++++++++++++++++++++++++++++++++ doc/compute_reduce.txt | 95 ++++++++++++++++++++++++++++++++++ 4 files changed, 203 insertions(+), 2 deletions(-) create mode 100644 doc/compute_reduce.html create mode 100644 doc/compute_reduce.txt diff --git a/doc/Section_commands.html b/doc/Section_commands.html index 759239baa5..1fa9522635 100644 --- a/doc/Section_commands.html +++ b/doc/Section_commands.html @@ -334,7 +334,7 @@ description:

- +
centro/atomcoord/atomdisplace/atomgroup/groupke/atompe
pe/atompressurerotate/dipolerotate/granstress/atomsum
pe/atompressurereducerotate/dipolerotate/granstress/atom
temptemp/aspheretemp/deformtemp/dipoletemp/partialtemp/ramp
temp/region
diff --git a/doc/compute.html b/doc/compute.html index db09256bce..8285934ce8 100644 --- a/doc/compute.html +++ b/doc/compute.html @@ -117,10 +117,10 @@ available in LAMMPS:
  • pe - potential energy
  • pe/atom - potential energy for each atom
  • pressure - total pressure and pressure tensor +
  • reduce - combine per-atom quantities into a single global value
  • rotate/dipole - rotational energy of dipolar atoms
  • rotate/gran - rotational energy of granular atoms
  • stress/atom - stress tensor for each atom -
  • sum - sum per-atom quantities to a global value
  • temp - temperature of group of atoms
  • temp/asphere - temperature of aspherical particles
  • temp/deform - temperature excluding box deformation velocity diff --git a/doc/compute_reduce.html b/doc/compute_reduce.html new file mode 100644 index 0000000000..a160b43b5c --- /dev/null +++ b/doc/compute_reduce.html @@ -0,0 +1,106 @@ + +
    LAMMPS WWW Site - LAMMPS Documentation - LAMMPS Commands +
    + + + + + + +
    + +

    compute reduce command +

    +

    Syntax: +

    +
    compute ID group-ID reduce mode input1 input2 ... 
+
    + +

    Examples: +

    +
    compute 1 all reduce sum c_force
+compute 2 all reduce min c_press2 f_ave v_myKE 
+
    +

    Description: +

    +

    Define a calculation that "reduces" one or more per-atom inputs across +all atoms in the group to yield a single global scalar for each listed +input. The resulting value(s) can be accessed by any command that +uses global computes, e.g. the thermo custom +command or fix ave/time command or by a +variable command. See this +section of the documentation for an overview +of output options. +

    +

    The reduction operation is specified by the mode setting. The sum +option adds the per-atom quantities into a global total. The min or +max options find the minimum or maximum value across all per-atom +quantities. +

    +

    Each listed input is operated on independently. The group specified +with the command means only atoms within the group contribute to the +result. Note that the input that produces the per-atom quantities may +define its own group which affects the quantities it returns. For +example, if a per-atom compute is used as an input, it will generate +values of 0.0 for atoms that are not in the group specified for that +compute. +

    +

    Each listed input can be an atom attribute (position, velocity, force +component) or can be the result of a compute or +fix or the evaluation of an atom-style +variable. In the latter cases, the compute, fix, or +variable must produce per-atom quantities, not a global quantity. +

    +

    Computes that produce per-atom quantities are those +which have the word atom in their style name. See the doc pages for +individual fixes to determine which ones produce per-atom +quantities. Variables of style atom are the only +ones that can be used with this compute since all other variable +styles produce global quantities. +

    +

    If a single input is specified this compute produces a global scalar +value. If multiple inputs are specified, this compute produces a +vector of global values, the length of which is equal to the number of +inputs specified. +

    +

    The value(s) produced by this compute are all "extensive", meaning +their value scales linearly with the number of atoms involved. If +normalized values are desired, this compute can be accessed by the +thermo_style custom command with thermo_modify +norm yes set as an option. Or it can be accessed +by a variable that divides by the appropriate atom +count. +

    +

    Output info: +

    +

    The scalar and vector values calculated by this compute are +"extensive", meaning they scale with the number of atoms in the +simulation. +

    +

    Restrictions: none +

    +

    Related commands: +

    +

    compute, fix, variable +

    +

    Default: none +

    + diff --git a/doc/compute_reduce.txt b/doc/compute_reduce.txt new file mode 100644 index 0000000000..769b33562e --- /dev/null +++ b/doc/compute_reduce.txt @@ -0,0 +1,95 @@ +"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c + +:link(lws,http://lammps.sandia.gov) +:link(ld,Manual.html) +:link(lc,Section_commands.html#comm) + +:line + +compute reduce command :h3 + +[Syntax:] + +compute ID group-ID reduce mode input1 input2 ... :pre + +ID, group-ID are documented in "compute"_compute.html command :ulb,l +reduce = style name of this compute command :l +mode = {sum} or {min} or {max} :l +one or more inputs can be listed :l +input = x, y, z, vx, vy, vz, fx, fy, fz, c_ID, c_ID\[N\], f_ID, f_ID\[N\], v_name :l + x,y,z,vx,vy,vz,fx,fy,fz = atom attribute (position, velocity, force component) + c_ID = per-atom scalar value calculated by a compute with ID + c_ID\[N\] = Nth component of per-atom vector calculated by a compute with ID + f_ID = per-atom scalar value calculated by a fix with ID + f_ID\[N\] = Nth component of per-atom vector calculated by a fix with ID + v_name = per-atom value calculated by an atom-style variable with name :pre +:ule + +[Examples:] + +compute 1 all reduce sum c_force +compute 2 all reduce min c_press[2] f_ave v_myKE :pre + +[Description:] + +Define a calculation that "reduces" one or more per-atom inputs across +all atoms in the group to yield a single global scalar for each listed +input. The resulting value(s) can be accessed by any command that +uses global computes, e.g. the "thermo custom"_therml_style.html +command or "fix ave/time"_fix_ave_time.html command or by a +"variable"_variable.html command. See "this +section"_Section_howto.html#4_15 of the documentation for an overview +of output options. + +The reduction operation is specified by the {mode} setting. The {sum} +option adds the per-atom quantities into a global total. The {min} or +{max} options find the minimum or maximum value across all per-atom +quantities. + +Each listed input is operated on independently. The group specified +with the command means only atoms within the group contribute to the +result. Note that the input that produces the per-atom quantities may +define its own group which affects the quantities it returns. For +example, if a per-atom compute is used as an input, it will generate +values of 0.0 for atoms that are not in the group specified for that +compute. + +Each listed input can be an atom attribute (position, velocity, force +component) or can be the result of a "compute"_compute.html or +"fix"_fix.html or the evaluation of an atom-style +"variable"_variable.html. In the latter cases, the compute, fix, or +variable must produce per-atom quantities, not a global quantity. + +"Computes"_compute.html that produce per-atom quantities are those +which have the word {atom} in their style name. See the doc pages for +individual "fixes"_fix.html to determine which ones produce per-atom +quantities. "Variables"_variable.html of style {atom} are the only +ones that can be used with this compute since all other variable +styles produce global quantities. + +If a single input is specified this compute produces a global scalar +value. If multiple inputs are specified, this compute produces a +vector of global values, the length of which is equal to the number of +inputs specified. + +The value(s) produced by this compute are all "extensive", meaning +their value scales linearly with the number of atoms involved. If +normalized values are desired, this compute can be accessed by the +"thermo_style custom"_thermo_style.html command with "thermo_modify +norm yes"_thermo_modify.html set as an option. Or it can be accessed +by a "variable"_variable.html that divides by the appropriate atom +count. + +[Output info:] + +The scalar and vector values calculated by this compute are +"extensive", meaning they scale with the number of atoms in the +simulation. + +[Restrictions:] none + +[Related commands:] + +"compute"_compute.html, "fix"_fix.html, "variable"_variable.html + +[Default:] none