The bivar module will resample 1d scatter data in 3 variables. A
typical use for this module is to take a field of 3-coordinate,
scalar values, and resample over a "regular" grid.
The algorithm used is one in which, for each output grid location,
all input points are scanned to determine if they lie within the
specified search radius. If so, that input point's contribution
is weighted as a function of distance from the output grid point
and scaled by 1./distance**weightfunction. As such, this module
is best suited for use on input data which doesn't necessarily
fit a diffentiable function. For such data, refer to the scat3d
module.
INPUTS
Data Field (required; field 1D irregular 3-coordinate scalar)
The input field consists of a 1D field (scatter data) which
has scalar floating point data, and associated x,y,z
coordinate information.
PARAMETERS
Xmin,Xmax,Ymin,Ymax,Zmin,Zmax
The values of these variables define the coordinate range of
the grid over which the input data will be resampled. These
values may be adjusted, for example, to form a bounding box
around all the input data, or to look at a box enclosing
some volume within the input data.
Xsamples, Ysamples, Zsamples
These values define the resolution of the resampling grid.
Increasing these values will result in a "finer" grid,
decreasing these values will result in a "coarser" grid
(over the same coordinate range defined by Xmin,Xmax, etc.).
Search Radius
This floating point value sets the limit over which input
scatter points will influence the value at a given output
point. Increasing this value will allow more points to
influence the value at a given output grid point, while
decreasing this value will cause fewer points to be
considered.
Weight Function
This floating point value is used to "weight" the contribution
of a given input point to a given output value. Increasing this
value will lessen the contribution of input points "further
away" than "closer" points at a given grid location. In other
words, points which are "closer" to a given grid location have
significantly more influence than those further away. Decreasing
this value will increase the influence of points closer to the
limits of the Search Radius.
Undef Value
This value is placed at those output grid locations in which no
input values lie within the Search Radius.
OUTPUTS
Field 2D irregular 3-coordinate scalar float
The output field is an "irregular" field consisting of
three data dimensions and two coordinate dimensions.
The data is a scalar floating point value.