A cylindrical coordinate system is a three-dimensional coordinate system that specifies point positions by the distance from a chosen reference axis, the direction from the axis relative to a chosen reference direction, and the distance from a chosen reference plane perpendicular to the axis. The latter distance is given as a positive or negative number depending on which side of the reference plane faces the point.
The origin of the system is the point where all three coordinates can be given as zero. This is the intersection between the reference plane and the axis. The axis is variously called the cylindrical or longitudinal axis, to differentiate it from the polar axis, which is the ray that lies in the reference plane, starting at the origin and pointing in the reference direction. The distance from the axis may be called the radial distance or radius, while the angular coordinate is sometimes referred to as the angular position or as the azimuth. The radius and the azimuth are together called the polar coordinates, as they correspond to a two-dimensional polar coordinate system in the plane through the point, parallel to the reference plane. The third coordinate may be called the height or altitude (if the reference plane is considered horizontal), longitudinal position, or axial position.

Use of Cylindrical Coordinates in Tensegrity Mathematics

Cylindrical coordinates are useful in connection with tensegrity structures because many of them feature rotational symmetry about a longitudinal axis.
See also, Twist Angle theorem.

## Cylindrical Coordinates

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cylindrical coordinate systemis a three-dimensional coordinate system that specifies point positions by the distance from a chosen reference axis, the direction from the axis relative to a chosen reference direction, and the distance from a chosen reference plane perpendicular to the axis. The latter distance is given as a positive or negative number depending on which side of the reference plane faces the point.The

originof the system is the point where all three coordinates can be given as zero. This is the intersection between the reference plane and the axis. The axis is variously called thecylindricalorlongitudinalaxis, to differentiate it from thepolar axis, which is the ray that lies in the reference plane, starting at the origin and pointing in the reference direction. The distance from the axis may be called theradial distanceorradius, while the angular coordinate is sometimes referred to as theangular positionor as theazimuth. The radius and the azimuth are together called thepolar coordinates, as they correspond to a two-dimensional polar coordinate system in the plane through the point, parallel to the reference plane. The third coordinate may be called theheightoraltitude(if the reference plane is considered horizontal),longitudinal position, oraxial position.## Use of Cylindrical Coordinates in Tensegrity Mathematics

Cylindrical coordinates are useful in connection with tensegrity structures because many of them feature rotational symmetry about a longitudinal axis.See also, Twist Angle theorem.

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