Next: polate, Previous: pointer, Up: Internal Routines [Contents][Index]

`polartossfc(`

`coords` [, `level`])

Converts polar coordinates to SSFCs (SierpiÅski Surface-Filling Coordinates). An ssfc (http://ssfc.quae.nl) indicates a position on the surface of a sphere with just one coordinate rather than with the usual two coordinates.

The

must contain at least two elements in its
first dimension, which are taken to be the latitude and longitude of
the point, measured in radians. (Multiply by `coords``#deg`

to convert
from degrees to radians; #deg.)

If

is specified, then the returned value for each
point is the ssfc index at the indicated level. The ssfc index ranges
between 0 and `level``2^`

. The corresponding real number
is obtained by dividing the ssfc index by `level` - 1`2^`

. Each
next element of `level`

is used for each next data point
from `level`

. If `coords`

runs out of elements
before `level`

runs out of points, then the last element
of `coords`

is reused for the remaining points.
`level`

If

is not specified, then the returned value for
each point is the decimal ssfc index represented as a `level``double`

number between 0 and 1, to the highest precision that can be expressed
by a `double`

.

See also: ssfctopolar