Rope (data structure)

In computer programming, a rope, or cord, is a data structure composed of smaller strings that is used for efficiently storing and manipulating a very long string. For example, a text editing program may use a rope to represent the text being edited, so that operations such as insertion, deletion, and random access can be done efficiently.

Description

A rope is a binary tree having leaf nodes that contain a short string. Each node has a weight value equal to the length of its string plus the sum of all leaf nodes' weight in its left subtree, namely the weight of a node is the total string length in its left subtree for a non-leaf node, or the string length of itself for a leaf node. Thus a node with two children divides the whole string into two parts: the left subtree stores the first part of the string. The right subtree stores the second part and its weight is the sum of the left child's weight and the length of its contained string.

The binary tree can be seen as several levels of nodes. The bottom level contains all the nodes that contain a string. Higher levels have fewer and fewer nodes. The top level consists of a single "root" node. The rope is built by putting the nodes with short strings in the bottom level, then attaching a random half of the nodes to parent nodes in the next level.

Rope (unit)

A rope may refer to any of several units of measurement initially determined or formed by ropes or knotted cords.

Length

The Greco-Roman schoenus, supposedly based on an Egyptian unit derived from a wound reed measuring rope, may also be given in translation as a "rope". According to Strabo, it varied in length between 30 to 120 stadia (roughly 5 to 20 km) depending on local custom.

The Byzantine equivalent, the schoinion or "little rope", varied between 60 to 72 Greek feet depending upon the location.

The Thai sen of 20 Thai fathoms or 40 m also means and is translated "rope".

The Somerset rope was a former English unit used in drainage and hedging. It was 20 feet (now precisely 6.096 m).

Area

The Romans used the schoenus as an alternate name for the half-jugerum formed by a square with sides of 120 Roman feet.

In Somerset, the rope could also double as a measure of area equivalent to 20 feet by 1 foot. Walls in Somerset were formerly sold "per rope" of 20 sq ft.

Garlic

In medieval English units, the rope of garlic was a set unit of 15 heads of garlic. 15 such ropes made up the "hundred" of garlic.

Rope (rhythmic gymnastics)

Rope (rhythmic gymnastics) may be made of hemp or a synthetic material which retains the qualities of lightness and suppleness. Its length is in proportion to the size of the gymnast. The rope should, when held down by the feet, reach both of the gymnasts' armpits. One or two knots at each end are for keeping hold of the rope while doing the routine. At the ends (to the exclusion of all other parts of the rope) an anti-slip material, either coloured or neutral may cover a maximum of 10 cm (3.94 in). The rope must be coloured, either all or partially. It may be either of a uniform diameter or be progressively thicker in the center provided that this thickening is of the same material as the rope.

The fundamental requirements of a rope routine include leaps and skipping. Other elements include swings, throws, circles, rotations and figures of eight.

Dial

Dial may refer to:

Mechanical device

DIAL

Other

Dial (band)

Dial is a progressive rock band based in the Netherlands.

History

Dial was founded in late 2003 by Liselotte Hegt, Rommert van der Meer and Kristoffer Gildenlöw. Early on, the band was pure a hobby but after Kristoffer's departure from Swedish prog metal band Pain of Salvation in early 2006, the band headed towards a more serious destiny.

In summer 2006, the band went to Austria to record their debut album Synchronized together with producer Devon Graves (of Deadsoul Tribe and Psychotic Waltz). This album was released in May 2007 through Prog Rock Records (US).

Line-up

External links

Rotary dial

A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing. It is used when initiating a telephone call to transmit the destination telephone number to a telephone exchange.

On the rotary dial, the digits are arranged in a circular layout so that a finger wheel may be rotated with one finger from the position of each digit to a fixed stop position, implemented by the finger stop, which is a mechanical barrier to prevent further rotation. When released at the finger stop, the wheel returns to its home position by spring action at a speed regulated by a governor device. During this return rotation, the dial interrupts the direct electrical current of the telephone line (local loop) a specific number of times for each digit and thereby generates electrical pulses which the telephone exchange decodes into each dialed digit. Each of the ten digits are encoded in sequences of up to ten pulses. For this reason, the method is sometimes called decadic dialling.