WY Posn Util🔗 i

Andrew Mauer-Oats

This package implements a stack of functions for working with "posn"s.

procedure
( posn=? pq)→boolean?
p:posn?
q:posn?

True when two posns have the same coordinates.

procedure
( posn-add pq)→posn?
p:posn?
q:posn?

Sum each coordinate separately.

procedure
( posn-subtract pq)→posn?
p:posn?
q:posn?

Coordinates of p minus the coordinates of q.

procedure
( posn-scale kp)→posn?
k:number?
p:posn?

Multiply each coordinate of p by the same number k.

procedure
( posn-distance pq)→nonnegative-real?
p:posn?
q:posn?

The Euclidean distance between the points specified by p and q.

procedure
( place-image/posn imgptbg)→image?
img:image?
pt:posn?
bg:image?

Place img at the coordinates specified by pt on the bg image.

procedure
( posn-length p)→nonnegative-real?
p:posn?

The length of the vector p.

procedure
( posn-length-squared p)→nonnegative-real?
p:posn?

The square of the length of the vector p. This will be an integer if the coordinates of p are integers.

procedure
( posn-within? pqeps)→boolean?
p:posn?
q:posn?
eps:real?

True if each of the corresponding components of p and q are within eps of each other.

procedure
( posn-unit p)→posn?
p:posn?

The posn p rescaled so it is of unit length.

procedure
( posn-dotpq)→real?
p:posn?
q:posn?

The dot product.

procedure
( posn-projection pq)→real?
p:posn?
q:posn?

The projection of p on q. This is the length of the shadow of p on q when the sun shines perpendicular to q.

procedure
( posn-angle-between-rad pq)→real?
p:posn?
q:posn?

The angle between the vectors, in radians. Uses acos .

procedure
( posn-angle-between-deg pq)→real?
p:posn?
q:posn?

The angle between the vectors, in degrees. Uses acos .

procedure
( xy->polar p)→posn?
p:posn?

Convert from rectangular to polar representation (radius, angle).

procedure
( polar->xy q)→posn?
q:posn?

Convert from polar representation (radius, angle) to rectangular (x,y).

top ← prev up next →