The FIELD Command option manipulates one or more specified fields in the Current Mesh Object
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/
compose the field value with the specified composition function for all points in the specified point set. 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))
mfedraw 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.
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.
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.
## EXAMPLES
field/compose/asinh/1,0,0/field/scale/normalize/4.field/volavg/voronoi/4/1