n[0-9]+

integer[+-]?{n}

real[+-]?({n}\.{n}?)|(\.{n})

real[+-]?({n}\.{n}?|\.{n})

FLOAT({integer}|{real})([eE]{integer})?

O_BRACKET\[

C_BRACKET\]

PRECISION

=========

Values are stored internally as32-bit floating point numbers. This means that

numbers with more than7 significant digits will be truncated.

Values are stored internally as64-bit floating point numbers. This means that

numbers with more thanabout 16 significant digits will be truncated.

USAGE

reasonably good sorting in most cases, which is useful if

you want to use ORDER BY with this type

The following functions are available:

cube_distance(cube, cube) returns double

cube_distance returns the distance between two cubes. If both cubes are

points, this is the normal distance function.

cube(text) returns cube

cube takes text input and returns a cube. This is useful for making cubes

from computed strings.

cube_dim(cube) returns int

cube_dim returns the number of dimensions stored in the the data structure

for a cube. This is useful for constraints on the dimensions of a cube.

cube_ll_coord(cube, int) returns double

cube_ll_coord returns the nth coordinate value for the lower left corner

of a cube. This is useful for doing coordinate transformations.

cube_ur_coord(cube, int) returns double

cube_ur_coord returns the nth coordinate value for the upper right corner

of a cube. This is useful for doing coordinate transformations.

cube_is_point(cube) returns bool

cube_is_point returns true if a cube is also a point. This is true when the

two defining corners are the same.

cube_enlarge(cube, double, int) returns cube

cube_enlarge increases the size of a cube by a specified radius in at least

n dimensions. If the radius is negative the box is shrunk instead. This

is useful for creating bounding boxes around a point for searching for

nearby points. All defined dimensions are changed by the radius. If n

is greater than the number of defined dimensions and the cube is being

increased (r >= 0) then 0 is used as the base for the extra coordinates.

LL coordinates are decreased by r and UR coordinates are increased by r. If

a LL coordinate is increased to larger than the corresponding UR coordinate

(this can only happen when r < 0) than both coordinates are set to their

average.

There are a few other potentially useful functions defined in cube.c

that vanished from the schema because I stopped using them. Some of

these were meant to support type casting. Let me know if I was wrong:

Argonne, IL 60439-4844

selkovjr@mcs.anl.gov

------------------------------------------------------------------------

Minor updates to this package were made by Bruno Wolff III <bruno@wolff.to>

in August of 2002.

These include changing the precision from single precision to double

precision and adding some new functions.