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projectmap(map, height [, hdist=hdist,
angle=angle, mag=mag, xmap=xmap, ymap=ymap,
size=size])
Returns a projected version of the two-dimensional map
,
which must be a numerical array. The eye is height
units
above the map, measured in units of one map element (as are all linear
measurements in the argument list). The returned array has the same
data type as map
. By default, the returned array has 512
by 512 elements and shows the central height
by
height
elements of map
.
hdist
, which defaults to 0, indicates the horizontal
distance of the eye from the chosen center of the projection.
angle
, which defaults to 0, indicates the direction of the
horizontal displacement of the eye, such that an angle of zero yields
the same orientation as tv,map
, and an increase of the
angle leads to a clockwise rotation of the projection.
mag
, which defaults to 1, indicates the linear
magnification factor. A greater mag
leads to a smaller
fraction of the map being visible in the result. xmap
and
ymap
indicate the map coordinates of the chosen center of
the projection. This location defaults to the center of the map, i.e.,
to dimen(map)/2
. size
, which defaults to 512,
indicates the linear size of the array that is returned. If
size
is a scalar, then its value is taken for both
dimensions. If it is an array, then the first two of its elements are
taken for the dimensions. If hdist
is zero, then the
greatest dimension of the output array spans
height/mag
elements of the map.