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documentation/lagrit_manual/commands/field.txt

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+.. _field :
+
+&nbsp_place_holder;
+
+> **_FIELD_**
+
+>
+
+>> The FIELD Command option manipulates one or more specified fields in the
+Current Mesh Object
+
+>>
+
+>> *For all points in the specified point set, we compose the field value with
+the specified composition function. The composition functions allowed are
+currently **asinh** and **log**. So, for example, if 'i' is in the point set
+and **asinh** is the composition function, we have the assignment:
+
+>>
+
+>>> field(i) = asinh(field(i)).
+
+>>
+
+>> *The **field**/**mfedraw **command causes a binary dump of the specified
+fields to two files in the **mfedraw** input format. **mfedraw** is a graphics
+package for visualizing moving piecewise linear functions of two variables,
+such as those originally encountered in Moving Finite Elements. The files are
+named 'root1.bin' and 'root2.bin', where 'root' is the root file name
+argument. Because the graphics data are a function of two variables, you must
+supply two orthonormal vectors (x1,y1,z1) and (x2,y2,z2) which specify the
+graphics coordinate axes. More precisely, given 3D coordinates (x,y,z), the 2D
+graphic coordinates will then be (x*x1+y*y1+z*z1 , x*x2+y*y2+z*z2). So, for
+example, the choice:
+
+>>
+
+>>> /x1,y1,z1/x2,y2,z2/ = /1.,0.,0./0.,1.,0./
+
+>>
+
+>> causes the 'z' coordinate to be discarded while the 'x' and 'y' coordinates
+are unchanged.
+
+>>
+
+>> *The **field**/**scale** option scales the field values of the specified
+points. scale option can take on the values **normalize**, **multiply**, and
+**divide**. If **normalize **is specified, we multiply all the field values by
+**factor**/(fieldmax-fieldmin), where 'fieldmax' and 'fieldmin' are the
+maximum and minimum values taken over the point set. This has the effect of
+normalizing the field so that the new difference between the maximum and
+minimum values is equal to **factor**. If **multiply** is specified, we
+multiply all the field values in the point set by **factor**. If **divide **is
+specified, we divide all the field values in the point set by **factor.**
+
+>>
+
+>> *The **field**/**volavg** option, for all the members of the point set and
+for all specified fields, replaces the point field values with values that
+represent the average of the field(s) over the control volumes associated with
+the points. The averaging option specifies what kind of control volume is to
+be used; the choices are **voronoi** and** median**. iterations is an integer
+that specifies a repeat count for how many times this procedure is to be
+performed on the field(s). The affect of this process is to broaden and smooth
+the features of the field(s), similar to the effect of a diffusion process.
+The **voronoi **choice, unlike the **median**. choice, produces a diffusive
+effect independent of mesh connectivity. However, again unlike the **median**.
+choice, it _requires_ that the mesh be Delaunay, or incorrect results will
+occur.
+
+>
+
+> FORMAT:
+
+>
+
+>> **field**/**compose**/composition function/ifirst,ilast,istride/field list/
+
+**field**/**mfedraw**/root file name/x1,y1,z1/x2,y2,z2/field list/   
+**field/scale /**scale option/factor/ifirst,ilast,istride/ field list /   
+**field**/**volavg**/averaging option/iterations/ifirst,ilast,istride/filed list/
+>
+
+> EXAMPLES:
+
+>
+
+>> **field**/**compose**/**asinh**/1,0,0/**field**/**scale**/**normalize**/4.*
+*field**/**volavg**/**voronoi**/4/1,
+
+>
+
+> &nbsp_place_holder;
+
+&nbsp_place_holder;
+