CullPyr

DESCRIPTION

CullPyr is used to select a portion of a pyramid datatype. The selection is performed in the data space and is accomplished by using the Data Min and Data Max dials.

CullPyr is useful for converting a lattice with illegal values into a dataset that can be manipulated within IRIS Explorer. The standard way to do this is create a pyramid from the input lattice (using LatToPyr), then wire that pyramid into CullPyr. By setting both dials to the single excluded value and setting range to "Keep exclusive," the output pyramid will reference only legal datavalues.

Culling is performed at the highest level of the pyramid. Elements at the highest level either are passed through or not, based on whether the data values of the lattice entries it references are within the culling range, respectively outside of it, depending on the value of the Range widget. The lattice used can either be the base lattice, or the top-level lattice if it exists. If the data value of any vertex/cell lies outside the range, respectively inside, the element will not be passed along.

The decision whether to cull a point is base on a single channel of the input base lattice, but all channels of the base lattice are preserved in the output pyramid.

CullPyr is an alternate executable module depending on the CropPyr executable.

INPUTS

Port: Input
Type: Pyramid
Constraints: 1..-layer
Constraints: 1..-baseLat
Constraints: n-D compression
Constraints: n-compression type
This is the input pyramid.

WIDGETS

Port: Data Min
Type: Dial
This is the minimum x value of the culling range.

Port: Data Max
Type: Dial
This is the maximum x value of the culling range.

Port: Channel
Type: Slider
The data variable channel to govern culling.

Port: Range
Type: Radio Box
Menu Item: Keep inclusive
Menu Item: Keep exclusive
The selection of whether to keep values inside the [DataMin, DataMax] range, or to keep values outside the range [DataMin, DataMax]. Here we use [] braces to mean an inclusive range.

Port: Level
Menu Item: Vertex Data
Menu Item: Top Level Data
This widget decides whether to perform culling on data defined on the base lattice, or data defined on the top-level lattice, if any.

OUTPUTS

Port: Output
Type: Pyramid
Constraints: 1..-layer
Constraints: 1..-baseLat
Constraints: n-D compression
Constraints: n-compression type
This is the culled output pyramid.

KNOWN PROBLEMS

Culling is performed at the highest level of the pyramid. This means that if the highest level contains a single entry that references everything, the output of this module will be everything or nothing.

SEE ALSO

CropPyr.
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© The Numerical Algorithms Group Ltd, Oxford UK. 2000