git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@4030 f3b2605a-c512-4ea7-a41b-209d697bcdaa

doc/fix_addforce.html

@@ -68,6 +68,8 @@ field with optional time-dependence as well.
 specified geometric <A HREF = "region.html">region</A> in order to have force added
 to it.
 </P>
+<HR>
+
 <P>Adding a force to atoms implies a change in their potential energy as
 they move due to the applied force field.  For dynamics via the "run"
 command, this energy can be optionally added to the system's potential
@@ -98,8 +100,10 @@ atom as function of its position.  Unlike variables used for <I>fx</I>,
 <P>Note that when the <I>energy</I> keyword is used during an energy
 minimization, you must insure that the formula defined for the
 atom-style <A HREF = "variable.html">variable</A> is consistent with the force
-variable formulas, i.e. that -Grad(E) = F.  If you don't, the
-minimization will not converge properly.
+variable formulas, i.e. that -Grad(E) = F.  For example, if the force
+were a spring-like F = kx, then the energy formula should be E =
+-0.5kx^2.  If you don't do this correctly, the minimization will not
+converge properly.
 </P>
 <P><B>Restart, fix_modify, output, run start/stop, minimize info:</B>
 </P>

doc/fix_addforce.txt

@@ -58,6 +58,8 @@ If the {region} keyword is used, the atom must also be in the
 specified geometric "region"_region.html in order to have force added
 to it.
 
+:line
+
 Adding a force to atoms implies a change in their potential energy as
 they move due to the applied force field.  For dynamics via the "run"
 command, this energy can be optionally added to the system's potential

doc/fix_setforce.html

@@ -15,10 +15,22 @@
 </P>
 <PRE>fix ID group-ID setforce fx fy fz 
 </PRE>
-<UL><LI>ID, group-ID are documented in <A HREF = "fix.html">fix</A> command
-<LI>setforce = style name of this fix command
-<LI>fx,fy,fz = force component values
+<UL><LI>ID, group-ID are documented in <A HREF = "fix.html">fix</A> command 
+
+<LI>setforce = style name of this fix command 
+
+<LI>fx,fy,fz = force component values 
+
 <LI>any of fx,fy,fz can be a variable (see below) 
+
+<LI>zero or more keyword/value pairs may be appended to args 
+
+<LI>keyword = <I>region</I>  
+
+<PRE>  <I>region</I> value = region-ID
+    region-ID = ID of region atoms must be in to have added force 
+</PRE>
+
 </UL>
 <P><B>Examples:</B>
 </P>
@@ -54,6 +66,10 @@ variables but can also include per-atom values, such as atom
 coordinates.  Thus it is easy to specify a spatially-dependent force
 field with optional time-dependence as well.
 </P>
+<P>If the <I>region</I> keyword is used, the atom must also be in the
+specified geometric <A HREF = "region.html">region</A> in order to have force added
+to it.
+</P>
 <P><B>Restart, fix_modify, output, run start/stop, minimize info:</B>
 </P>
 <P>No information about this fix is written to <A HREF = "restart.html">binary restart

doc/fix_setforce.txt

@@ -12,10 +12,15 @@ fix setforce command :h3
 
 fix ID group-ID setforce fx fy fz :pre
 
-ID, group-ID are documented in "fix"_fix.html command
-setforce = style name of this fix command
-fx,fy,fz = force component values
-any of fx,fy,fz can be a variable (see below) :ul
+ID, group-ID are documented in "fix"_fix.html command :ulb,l
+setforce = style name of this fix command :l
+fx,fy,fz = force component values :l
+any of fx,fy,fz can be a variable (see below) :l
+zero or more keyword/value pairs may be appended to args :l
+keyword = {region}  :l
+  {region} value = region-ID
+    region-ID = ID of region atoms must be in to have added force :pre
+:ule
 
 [Examples:]
 
@@ -51,6 +56,10 @@ variables but can also include per-atom values, such as atom
 coordinates.  Thus it is easy to specify a spatially-dependent force
 field with optional time-dependence as well.
 
+If the {region} keyword is used, the atom must also be in the
+specified geometric "region"_region.html in order to have force added
+to it.
+
 [Restart, fix_modify, output, run start/stop, minimize info:]
 
 No information about this fix is written to "binary restart