fix 1 all ave/spatial 10000 1 10000 z lower 0.02 c_myCentro units reduced &
title1 "My output values"
fix 1 flow ave/spatial 100 10 1000 y 0.0 1.0 vx vz norm sample file vel.profile
-fix 1 flow ave/spatial 100 5 1000 z lower 1.0 y 0.0 2.5 density/mass ave running
+fix 1 flow ave/spatial 100 5 1000 z lower 1.0 y 0.0 2.5 density/mass ave running
+fix 1 flow ave/spatial 100 5 1000 z lower 1.0 y 0.0 2.5 density/mass bound y 5.0 20.0 discard yes ave running
Description:
@@ -405,6 +406,7 @@ simulation box size doesn't change or if the units keyword is set tocompute, fix ave/atom, fix ave/histo, fix ave/time, variable, fix ave/correlate, +fix ave/spatial/sphere
Default:
diff --git a/doc/fix_ave_spatial.txt b/doc/fix_ave_spatial.txt index c12713f65f..1487502e00 100644 --- a/doc/fix_ave_spatial.txt +++ b/doc/fix_ave_spatial.txt @@ -65,7 +65,8 @@ keyword = {region} or {discard} or {norm} or {ave} or {units} or {file} or {over fix 1 all ave/spatial 10000 1 10000 z lower 0.02 c_myCentro units reduced & title1 "My output values" fix 1 flow ave/spatial 100 10 1000 y 0.0 1.0 vx vz norm sample file vel.profile -fix 1 flow ave/spatial 100 5 1000 z lower 1.0 y 0.0 2.5 density/mass ave running :pre +fix 1 flow ave/spatial 100 5 1000 z lower 1.0 y 0.0 2.5 density/mass ave running +fix 1 flow ave/spatial 100 5 1000 z lower 1.0 y 0.0 2.5 density/mass bound y 5.0 20.0 discard yes ave running :pre [Description:] @@ -390,6 +391,7 @@ simulation box size doesn't change or if the {units} keyword is set to "compute"_compute.html, "fix ave/atom"_fix_ave_atom.html, "fix ave/histo"_fix_ave_histo.html, "fix ave/time"_fix_ave_time.html, "variable"_variable.html, "fix ave/correlate"_fix_ave_correlate.html, +"fix ave/spatial/sphere"_fix_ave_spatial_sphere.html [Default:] diff --git a/doc/fix_ave_spatial_sphere.html b/doc/fix_ave_spatial_sphere.html new file mode 100644 index 0000000000..d7d55d7257 --- /dev/null +++ b/doc/fix_ave_spatial_sphere.html @@ -0,0 +1,342 @@ + +Syntax: +
+fix ID group-ID ave/spatial/sphere Nevery Nrepeat Nfreq origin_x origin_y origin_z r_min r_max nbins value1 value2 ... keyword args ... ++
vx,vy,vz,fx,fy,fz = atom attribute (velocity, force component) + density/number, density/mass = number or mass density + c_ID = per-atom vector calculated by a compute with ID + c_ID[I] = Ith column of per-atom array calculated by a compute with ID + f_ID = per-atom vector calculated by a fix with ID + f_ID[I] = Ith column of per-atom array calculated by a fix with ID + v_name = per-atom vector calculated by an atom-style variable with name ++
region arg = region-ID + region-ID = ID of region atoms must be in to contribute to spatial averaging + norm arg = all or sample + units arg = box or lattice or reduced + ave args = one or running or window M + one = output new average value every Nfreq steps + running = output cumulative average of all previous Nfreq steps + window M = output average of M most recent Nfreq steps + file arg = filename + filename = file to write results to + overwrite arg = none = overwrite output file with only latest output + title1 arg = string + string = text to print as 1st line of output file + title2 arg = string + string = text to print as 2nd line of output file + title3 arg = string + string = text to print as 3rd line of output file ++ +
Examples: +
+fix 1 all ave/spatial/sphere 10000 1 10000 0.5 0.5 0.5 0.1 0.5 5 density/number vx vy vz units reduced title1 "My output values" +fix 1 flow ave/spatial/sphere 100 10 1000 20.0 20.0 20.0 0.0 20.0 20 vx vz norm sample file vel.profile ++
Description: +
+Use one or more per-atom vectors as inputs every few timesteps, bin +their values spatially into spherical shells based on current atom +coordinates, and average the bin values over longer timescales. The +resulting bin averages can be used by other output +commands such as thermo_style +custom, and can also be written to a file. +
+The group specified with the command means only atoms within the group +contribute to bin averages. If the region keyword is used, the atom +must be in both the group and the specified geometric +region in order to contribute to bin averages. +
+Each listed value can be an atom attribute (position, velocity, force +component), a mass or number density, or 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 a per-atom quantity, not a +global quantity. If you wish to time-average global quantities from a +compute, fix, or variable, then see the fix +ave/time command. +
+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 fix since all other styles of variable +produce global quantities. +
+The per-atom values of each input vector are binned and averaged +independently of the per-atom values in other input vectors. +
+Nbins specifies the number of spherical shells which will be created +between r_min and r_max centered at (origin_x, origin_y, origin_z). +
+IMPORTANT NOTE: This fix works by creating an array of size Nbins by +Nvalues on each processor. Nbins is the total number of bins; Nvalues +is the number of input values specified. Each processor loops over +its atoms, tallying its values to the appropriate bin. Then the +entire array is summed across all processors. This means that using a +large number of bins will incur an overhead in memory and computational +cost (summing across processors), so be careful to use reasonable numbers +of bins. +
+The Nevery, Nrepeat, and Nfreq arguments specify on what +timesteps the input values will be used to bin them and contribute to +the average. The final averaged quantities are generated on timesteps +that are a multiples of Nfreq. The average is over Nrepeat +quantities, computed in the preceding portion of the simulation every +Nevery timesteps. Nfreq must be a multiple of Nevery and +Nevery must be non-zero even if Nrepeat is 1. Also, the timesteps +contributing to the average value cannot overlap, i.e. Nfreq > +(Nrepeat-1)*Nevery is required. +
+For example, if Nevery=2, Nrepeat=6, and Nfreq=100, then values on +timesteps 90,92,94,96,98,100 will be used to compute the final average +on timestep 100. Similarly for timesteps 190,192,194,196,198,200 on +timestep 200, etc. If Nrepeat=1 and Nfreq = 100, then no time +averaging is done; values are simply generated on timesteps +100,200,etc. +
+The origin_x, origin_y, and origin_z parameters may be specified +by either a compute or a variable. This allows, for example, the +center of the spherical bins to be attached to the center of mass of a +group of atoms. If a variable origin is used and periodic boundary +conditions are in effect, then the origin will be wrapped across +periodic boundaries whenever it changes so that it is always inside +the simulation box. +
+The atom attribute values (vx,vy,vz,fx,fy,fz) are self-explanatory. +Note that other atom attributes (including atom postitions x,y,z) can +be used as inputs to this fix by using the compute +property/atom command and then specifying +an input value from that compute. +
+The density/number value means the number density is computed in +each bin, i.e. a weighting of 1 for each atom. The density/mass +value means the mass density is computed in each bin, i.e. each atom +is weighted by its mass. The resulting density is normalized by the +volume of the bin so that units of number/volume or density are +output. See the units command doc page for the +definition of density for each choice of units, e.g. gram/cm^3. +The bin volume will always be calculated in box units, independent +of the use of the units keyword in this command. +
+If a value begins with "c_", a compute ID must follow which has been +previously defined in the input script. If no bracketed integer is +appended, the per-atom vector calculated by the compute is used. If a +bracketed integer is appended, the Ith column of the per-atom array +calculated by the compute is used. Users can also write code for +their own compute styles and add them to LAMMPS. +
+If a value begins with "f_", a fix ID must follow which has been +previously defined in the input script. If no bracketed integer is +appended, the per-atom vector calculated by the fix is used. If a +bracketed integer is appended, the Ith column of the per-atom array +calculated by the fix is used. Note that some fixes only produce +their values on certain timesteps, which must be compatible with +Nevery, else an error results. Users can also write code for their +own fix styles and add them to LAMMPS. +
+If a value begins with "v_", a variable name must follow which has +been previously defined in the input script. Variables of style +atom can reference thermodynamic keywords and various per-atom +attributes, or invoke other computes, fixes, or variables when they +are evaluated, so this is a very general means of generating per-atom +quantities to spatially average. +
+Additional optional keywords also affect the operation of this fix. +The region keyword was discussed above. +
+The norm keyword affects how averaging is done for the output +produced every Nfreq timesteps. For an all setting, a bin +quantity is summed over all atoms in all Nrepeat samples, as is the +count of atoms in the bin. The printed value for the bin is +Total-quantity / Total-count. In other words it is an average over +the entire Nfreq timescale. +
+For a sample setting, the bin quantity is summed over atoms for only +a single sample, as is the count, and a "average sample value" is +computed, i.e. Sample-quantity / Sample-count. The printed value for +the bin is the average of the Nrepeat "average sample values", In +other words it is an average of an average. +
+The ave keyword determines how the bin values produced every Nfreq +steps are averaged with bin values produced on previous steps that +were multiples of Nfreq, before they are accessed by another output +command or written to a file. +
+If the ave setting is one, then the bin values produced on +timesteps that are multiples of Nfreq are independent of each other; +they are output as-is without further averaging. +
+If the ave setting is running, then the bin values produced on +timesteps that are multiples of Nfreq are summed and averaged in a +cumulative sense before being output. Each output bin value is thus +the average of the bin value produced on that timestep with all +preceding values for the same bin. This running average begins when +the fix is defined; it can only be restarted by deleting the fix via +the unfix command, or re-defining the fix by +re-specifying it. +
+If the ave setting is window, then the bin values produced on +timesteps that are multiples of Nfreq are summed and averaged within +a moving "window" of time, so that the last M values for the same bin +are used to produce the output. E.g. if M = 3 and Nfreq = 1000, then +the output on step 10000 will be the average of the individual bin +values on steps 8000,9000,10000. Outputs on early steps will average +over less than M values if they are not available. +
+The units keyword determines the meaning of the distance units used +for the sphere origin and the two radial lengths. For orthogonal +simulation boxes, any of the 3 options may be used. For +non-orthogonal (triclinic) simulation boxes, only the reduced option +may be used. +
+A box value selects standard distance units as defined by the +units command, e.g. Angstroms for units = real or metal. +A lattice value means the distance units are in lattice spacings. +The lattice command must have been previously used to +define the lattice spacing. +
+IMPORTANT NOTE: The lattice style may only be used if the lattice +spacing is the same in each direction. +
+A reduced value means normalized unitless values between 0 and 1, +which represent the lower and upper faces of the simulation box +respectively. Thus an origin value of 0.5 means the center of the +box in any dimension. +
+The file keyword allows a filename to be specified. Every Nfreq +timesteps, a section of bin info will be written to a text file in the +following format. A line with the timestep and number of bin is +written. Then one line per bin is written, containing the bin ID +(1-N), the coordinate of the center of the bin, the number of atoms in +the bin, and one or more calculated values. The number of values in +each line corresponds to the number of values specified in the fix +ave/spatial command. The number of atoms and the value(s) are average +quantities. If the value of the units keyword is box or +lattice, the "coord" is printed in box units. If the value of the +units keyword is reduced, the "coord" is printed in reduced units +(0-1). +
+The overwrite keyword will continuously overwrite the output file +with the latest output, so that it only contains one timestep worth of +output. This option can only be used with the ave running setting. +
+The title1 and title2 and title3 keywords allow specification of +the strings that will be printed as the first 3 lines of the output +file, assuming the file keyword was used. LAMMPS uses default +values for each of these, so they do not need to be specified. +
+By default, these header lines are as follows: +
+# Spatial-averaged data for fix ID and group name +# Timestep Number-of-bins +# Bin r Count value1 value2 ... ++
In the first line, ID and name are replaced with the fix-ID and group +name. The second line describes the two values that are printed at +the first of each section of output. In the third line the values are +replaced with the appropriate fields from the fix ave/spatial command. +The Coord2 and Coord3 entries in the third line only appear for 2d and +3d bins respectively. For 1d bins, the word Coord1 is replaced by +just Coord. +
+Restart, fix_modify, output, run start/stop, minimize info: +
+No information about this fix is written to binary restart +files. None of the fix_modify options +are relevant to this fix. +
+This fix computes a global array of values which can be accessed by +various output commands. The values can +only be accessed on timesteps that are multiples of Nfreq since that +is when averaging is performed. The global array has # of rows = +Nbins and # of columns = 2+Nvalues. The first column contains the +radius at the center of the shell. For units reduced, this is in +reduced units, while for units box and lattice this is in box +units. The next column has the count of atoms in that bin, and the +remaining columns are the Nvalue quantities. When the array is +accessed with an I that exceeds the current number of bins, than a 0.0 +is returned by the fix instead of an error. The array values +calculated by this fix are "intensive", since they are already +normalized by the count of atoms in each bin. +
+No parameter of this fix can be used with the start/stop keywords of +the run command. This fix is not invoked during energy +minimization. +
+Restrictions: +
+When the ave keyword is set to running or window then the number +of bins must remain the same during the simulation, so that the +appropriate averaging can be done. This will be the case if the +simulation box size doesn't change or if the units keyword is set to +reduced. +
+This style is part of the USER-MISC package. It is only enabled if +LAMMPS is build with that package. See the Making of +LAMMPS section for more info. +
+Related commands: +
+compute, fix ave/atom, fix +ave/histo, fix ave/time, +variable, fix ave/correlate, +fix ave/spatial, +
+Default: +
+The option defaults are norm = all, ave = one, units = lattice, no +file output, and title 1,2,3 = strings as described above. +
+ diff --git a/doc/fix_ave_spatial_sphere.txt b/doc/fix_ave_spatial_sphere.txt new file mode 100644 index 0000000000..65d078b8bf --- /dev/null +++ b/doc/fix_ave_spatial_sphere.txt @@ -0,0 +1,323 @@ +"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 + +fix ave/spatial/sphere command :h3 + +[Syntax:] + +fix ID group-ID ave/spatial/sphere Nevery Nrepeat Nfreq origin_x origin_y origin_z r_min r_max nbins value1 value2 ... keyword args ... :pre + +ID, group-ID are documented in "fix"_fix.html command :ulb,l +ave/spatial = style name of this fix command :l +Nevery = use input values every this many timesteps :l +Nrepeat = # of times to use input values for calculating averages :l +Nfreq = calculate averages every this many timesteps :l +origin_x, origin_y, origin_z = center of the sphere. can be the result of variables or computes (see below) :l +r_min = radial distance at which binning begins :l +r_max = radial distance at which binning ends :l +nbins = number of spherical shells to create between r_min and r_max :l +one or more input values can be listed :l +value = vx, vy, vz, fx, fy, fz, density/mass, density/number, c_ID, c_ID\[I\], f_ID, f_ID\[I\], v_name :l + vx,vy,vz,fx,fy,fz = atom attribute (velocity, force component) + density/number, density/mass = number or mass density + c_ID = per-atom vector calculated by a compute with ID + c_ID\[I\] = Ith column of per-atom array calculated by a compute with ID + f_ID = per-atom vector calculated by a fix with ID + f_ID\[I\] = Ith column of per-atom array calculated by a fix with ID + v_name = per-atom vector calculated by an atom-style variable with name :pre + +zero or more keyword/arg pairs may be appended :l +keyword = {region} or {norm} or {units} or {ave} or {file} or {overwrite} or {title1} or {title2} or {title3} :l + {region} arg = region-ID + region-ID = ID of region atoms must be in to contribute to spatial averaging + {norm} arg = {all} or {sample} + {units} arg = {box} or {lattice} or {reduced} + {ave} args = {one} or {running} or {window M} + one = output new average value every Nfreq steps + running = output cumulative average of all previous Nfreq steps + window M = output average of M most recent Nfreq steps + {file} arg = filename + filename = file to write results to + {overwrite} arg = none = overwrite output file with only latest output + {title1} arg = string + string = text to print as 1st line of output file + {title2} arg = string + string = text to print as 2nd line of output file + {title3} arg = string + string = text to print as 3rd line of output file :pre +:ule + +[Examples:] + +fix 1 all ave/spatial/sphere 10000 1 10000 0.5 0.5 0.5 0.1 0.5 5 density/number vx vy vz units reduced title1 "My output values" +fix 1 flow ave/spatial/sphere 100 10 1000 20.0 20.0 20.0 0.0 20.0 20 vx vz norm sample file vel.profile :pre + +[Description:] + +Use one or more per-atom vectors as inputs every few timesteps, bin +their values spatially into spherical shells based on current atom +coordinates, and average the bin values over longer timescales. The +resulting bin averages can be used by other "output +commands"_Section_howto.html#howto_15 such as "thermo_style +custom"_thermo_style.html, and can also be written to a file. + +The group specified with the command means only atoms within the group +contribute to bin averages. If the {region} keyword is used, the atom +must be in both the group and the specified geometric +"region"_region.html in order to contribute to bin averages. + +Each listed value can be an atom attribute (position, velocity, force +component), a mass or number density, or 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 a per-atom quantity, not a +global quantity. If you wish to time-average global quantities from a +compute, fix, or variable, then see the "fix +ave/time"_fix_ave_time.html command. + +"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 fix since all other styles of variable +produce global quantities. + +The per-atom values of each input vector are binned and averaged +independently of the per-atom values in other input vectors. + +{Nbins} specifies the number of spherical shells which will be created +between r_min and r_max centered at (origin_x, origin_y, origin_z). + +IMPORTANT NOTE: This fix works by creating an array of size Nbins by +Nvalues on each processor. Nbins is the total number of bins; Nvalues +is the number of input values specified. Each processor loops over +its atoms, tallying its values to the appropriate bin. Then the +entire array is summed across all processors. This means that using a +large number of bins will incur an overhead in memory and computational +cost (summing across processors), so be careful to use reasonable numbers +of bins. + +:line + +The {Nevery}, {Nrepeat}, and {Nfreq} arguments specify on what +timesteps the input values will be used to bin them and contribute to +the average. The final averaged quantities are generated on timesteps +that are a multiples of {Nfreq}. The average is over {Nrepeat} +quantities, computed in the preceding portion of the simulation every +{Nevery} timesteps. {Nfreq} must be a multiple of {Nevery} and +{Nevery} must be non-zero even if {Nrepeat} is 1. Also, the timesteps +contributing to the average value cannot overlap, i.e. Nfreq > +(Nrepeat-1)*Nevery is required. + +For example, if Nevery=2, Nrepeat=6, and Nfreq=100, then values on +timesteps 90,92,94,96,98,100 will be used to compute the final average +on timestep 100. Similarly for timesteps 190,192,194,196,198,200 on +timestep 200, etc. If Nrepeat=1 and Nfreq = 100, then no time +averaging is done; values are simply generated on timesteps +100,200,etc. + +:line + +The {origin_x}, {origin_y}, and {origin_z} parameters may be specified +by either a compute or a variable. This allows, for example, the +center of the spherical bins to be attached to the center of mass of a +group of atoms. If a variable origin is used and periodic boundary +conditions are in effect, then the origin will be wrapped across +periodic boundaries whenever it changes so that it is always inside +the simulation box. + +:line + +The atom attribute values (vx,vy,vz,fx,fy,fz) are self-explanatory. +Note that other atom attributes (including atom postitions x,y,z) can +be used as inputs to this fix by using the "compute +property/atom"_compute_property_atom.html command and then specifying +an input value from that compute. + +The {density/number} value means the number density is computed in +each bin, i.e. a weighting of 1 for each atom. The {density/mass} +value means the mass density is computed in each bin, i.e. each atom +is weighted by its mass. The resulting density is normalized by the +volume of the bin so that units of number/volume or density are +output. See the "units"_units.html command doc page for the +definition of density for each choice of units, e.g. gram/cm^3. +The bin volume will always be calculated in box units, independent +of the use of the {units} keyword in this command. + +If a value begins with "c_", a compute ID must follow which has been +previously defined in the input script. If no bracketed integer is +appended, the per-atom vector calculated by the compute is used. If a +bracketed integer is appended, the Ith column of the per-atom array +calculated by the compute is used. Users can also write code for +their own compute styles and "add them to LAMMPS"_Section_modify.html. + +If a value begins with "f_", a fix ID must follow which has been +previously defined in the input script. If no bracketed integer is +appended, the per-atom vector calculated by the fix is used. If a +bracketed integer is appended, the Ith column of the per-atom array +calculated by the fix is used. Note that some fixes only produce +their values on certain timesteps, which must be compatible with +{Nevery}, else an error results. Users can also write code for their +own fix styles and "add them to LAMMPS"_Section_modify.html. + +If a value begins with "v_", a variable name must follow which has +been previously defined in the input script. Variables of style +{atom} can reference thermodynamic keywords and various per-atom +attributes, or invoke other computes, fixes, or variables when they +are evaluated, so this is a very general means of generating per-atom +quantities to spatially average. + +:line + +Additional optional keywords also affect the operation of this fix. +The {region} keyword was discussed above. + +The {norm} keyword affects how averaging is done for the output +produced every {Nfreq} timesteps. For an {all} setting, a bin +quantity is summed over all atoms in all {Nrepeat} samples, as is the +count of atoms in the bin. The printed value for the bin is +Total-quantity / Total-count. In other words it is an average over +the entire {Nfreq} timescale. + +For a {sample} setting, the bin quantity is summed over atoms for only +a single sample, as is the count, and a "average sample value" is +computed, i.e. Sample-quantity / Sample-count. The printed value for +the bin is the average of the {Nrepeat} "average sample values", In +other words it is an average of an average. + +The {ave} keyword determines how the bin values produced every {Nfreq} +steps are averaged with bin values produced on previous steps that +were multiples of {Nfreq}, before they are accessed by another output +command or written to a file. + +If the {ave} setting is {one}, then the bin values produced on +timesteps that are multiples of {Nfreq} are independent of each other; +they are output as-is without further averaging. + +If the {ave} setting is {running}, then the bin values produced on +timesteps that are multiples of {Nfreq} are summed and averaged in a +cumulative sense before being output. Each output bin value is thus +the average of the bin value produced on that timestep with all +preceding values for the same bin. This running average begins when +the fix is defined; it can only be restarted by deleting the fix via +the "unfix"_unfix.html command, or re-defining the fix by +re-specifying it. + +If the {ave} setting is {window}, then the bin values produced on +timesteps that are multiples of {Nfreq} are summed and averaged within +a moving "window" of time, so that the last M values for the same bin +are used to produce the output. E.g. if M = 3 and Nfreq = 1000, then +the output on step 10000 will be the average of the individual bin +values on steps 8000,9000,10000. Outputs on early steps will average +over less than M values if they are not available. + +The {units} keyword determines the meaning of the distance units used +for the sphere origin and the two radial lengths. For orthogonal +simulation boxes, any of the 3 options may be used. For +non-orthogonal (triclinic) simulation boxes, only the {reduced} option +may be used. + +A {box} value selects standard distance units as defined by the +"units"_units.html command, e.g. Angstroms for units = real or metal. +A {lattice} value means the distance units are in lattice spacings. +The "lattice"_lattice.html command must have been previously used to +define the lattice spacing. + +IMPORTANT NOTE: The {lattice} style may only be used if the lattice +spacing is the same in each direction. + +A {reduced} value means normalized unitless values between 0 and 1, +which represent the lower and upper faces of the simulation box +respectively. Thus an {origin} value of 0.5 means the center of the +box in any dimension. + +The {file} keyword allows a filename to be specified. Every {Nfreq} +timesteps, a section of bin info will be written to a text file in the +following format. A line with the timestep and number of bin is +written. Then one line per bin is written, containing the bin ID +(1-N), the coordinate of the center of the bin, the number of atoms in +the bin, and one or more calculated values. The number of values in +each line corresponds to the number of values specified in the fix +ave/spatial command. The number of atoms and the value(s) are average +quantities. If the value of the {units} keyword is {box} or +{lattice}, the "coord" is printed in box units. If the value of the +{units} keyword is {reduced}, the "coord" is printed in reduced units +(0-1). + +The {overwrite} keyword will continuously overwrite the output file +with the latest output, so that it only contains one timestep worth of +output. This option can only be used with the {ave running} setting. + +The {title1} and {title2} and {title3} keywords allow specification of +the strings that will be printed as the first 3 lines of the output +file, assuming the {file} keyword was used. LAMMPS uses default +values for each of these, so they do not need to be specified. + +By default, these header lines are as follows: + +# Spatial-averaged data for fix ID and group name +# Timestep Number-of-bins +# Bin r Count value1 value2 ... :pre + +In the first line, ID and name are replaced with the fix-ID and group +name. The second line describes the two values that are printed at +the first of each section of output. In the third line the values are +replaced with the appropriate fields from the fix ave/spatial command. +The Coord2 and Coord3 entries in the third line only appear for 2d and +3d bins respectively. For 1d bins, the word Coord1 is replaced by +just Coord. + +:line + +[Restart, fix_modify, output, run start/stop, minimize info:] + +No information about this fix is written to "binary restart +files"_restart.html. None of the "fix_modify"_fix_modify.html options +are relevant to this fix. + +This fix computes a global array of values which can be accessed by +various "output commands"_Section_howto.html#howto_15. The values can +only be accessed on timesteps that are multiples of {Nfreq} since that +is when averaging is performed. The global array has # of rows = +Nbins and # of columns = 2+Nvalues. The first column contains the +radius at the center of the shell. For units {reduced}, this is in +reduced units, while for units {box} and {lattice} this is in box +units. The next column has the count of atoms in that bin, and the +remaining columns are the Nvalue quantities. When the array is +accessed with an I that exceeds the current number of bins, than a 0.0 +is returned by the fix instead of an error. The array values +calculated by this fix are "intensive", since they are already +normalized by the count of atoms in each bin. + +No parameter of this fix can be used with the {start/stop} keywords of +the "run"_run.html command. This fix is not invoked during "energy +minimization"_minimize.html. + +[Restrictions:] + +When the {ave} keyword is set to {running} or {window} then the number +of bins must remain the same during the simulation, so that the +appropriate averaging can be done. This will be the case if the +simulation box size doesn't change or if the {units} keyword is set to +{reduced}. + +This style is part of the USER-MISC package. It is only enabled if +LAMMPS is build with that package. See the "Making of +LAMMPS"_Section_start.html#3 section for more info. + +[Related commands:] + +"compute"_compute.html, "fix ave/atom"_fix_ave_atom.html, "fix +ave/histo"_fix_ave_histo.html, "fix ave/time"_fix_ave_time.html, +"variable"_variable.html, "fix ave/correlate"_fix_ave_correlate.html, +"fix ave/spatial"_fix_ave_spatial.html, + +[Default:] + +The option defaults are norm = all, ave = one, units = lattice, no +file output, and title 1,2,3 = strings as described above.