Contour
A contour line (also level set, isopleth, isoline, isogram or isarithm) for a function of two variables is a curve connecting points where the function has a same particular value. A contour map is a map illustrated with contour lines. more...
 Home
AMC
Acura
Alfa Romeo
Aston Martin
Audi
Austin
Austin Healey
BMW
Bentley
Buick
Cadillac
Chevrolet
Chrysler
Citroen
Cord
Daewoo
Datsun
DeLorean
DeSoto
Dodge
Eagle
Edsel
Ferrari
Fiat
Ford
 Aerostar
Aspire
Bronco
Bronco II
Contour
Crown Victoria
E-Series Van
Escape
Escort
Excursion
Expedition
Explorer
Explorer Sport
Explorer Sport Trac
F-100
F-150
F-250
F-350
Fairlane
Fairmont
Falcon
Five Hundred
Focus
Ford GT
Freestar
FreeStyle
Fusion
Galaxie
Model A
Model T
Mustang
Other
Other Pickups
Probe
Ranchero
Ranger
Taurus
Tempo
Thunderbird
Torino
Windstar
GMC
Geo
Honda
Hummer
Hyundai
Infiniti
International Harvester
Isuzu
Jaguar
Jeep
Kia
Lamborghini
Lancia
Land Rover
Lexus
Lincoln
Lotus
MG
Maserati
Mazda
Mercedes-Benz
Mercury
Mini
Mitsubishi
Nash
Nissan
Oldsmobile
Opel
Other Makes
Packard
Peugeot
Plymouth
Pontiac
Porsche
Renault
Replica/Kit Makes
Rolls-Royce
Saab
Saturn
Scion
Shelby
Studebaker
Subaru
Suzuki
Toyota
Triumph
Volkswagen
Volvo
Willys
The prefix iso-, the Greek prefix for "equal", refers to maps with lines that join points of equal value.
The gradient of the function is always perpendicular to the contour lines. When the lines are close together the length of the gradient is large: the variation is steep. If adjacent contour lines are of the same line width, the direction of the gradient cannot be determined from the contour lines alone. However if contour lines rotate through three or more widths, or if the lines are numerically labelled, then the direction of the gradient can also be determined from the contour lines.
Contour lines are curved or straight lines on a map describing the intersection of a real or hypothetical surface with one or more horizontal planes. The configuration of these contours allows map readers to infer relative gradient of a parameter and estimate that parameter at specific places. Contour lines may be either traced on a visible three-dimensional model of the surface, as when a photogrammetrist viewing a stereo-model plots elevation contours, or interpolated form estimated surface elevations, as when a computer program threads contours through a network of observation points ot area centroids. In the latter case, the method of interpolation affects the reliability of individual isolines and their portrayal of slope, pits and peaks (see Davis, 1986, Statistics and data analysis in geology).
Types of contour lines
Various types of contour lines are given different names according to the nature of the variable being mapped:
acid precipitation: isoplat.;
air pollutant: contour line.;
atmospheric density: isostere.;
aurora equal occurrence: isochasm;
biological events occurring with coincidence such as plants flowering: isophene;
cloud cover: isoneph;
illuminance: isophote.;
depth of water with equal temperature: isobathytherm.;
dew point: isodrosotherm.;
economic production: isoquant.;
elevation: contour lines on a topographic map or isohypse.;
underwater depth: isobath.;
humidity: isohume.;
ice formation location each winter: isopectic.;
linguistic features: isogloss;
liquid precipitation amount: isohyet.;
magnetic declination: isogon.;
magnetic declination annual change: isopor.;
ocean salinity: isohaline;
presence of linguistic feature: isogloss.;
pressure: isobar.;
radiation intensity: isodose.;
rainfall: isohyet.;
solar radiation: isohel.;
sound level: contour line.;
summer temperature mean: isothere.;
temperature: isotherm.;
temperature mean: isogeotherm.;
transport costs from the source of a raw material: isotim.;
volume: isochor.;
wind direction: isogon.;
wind speed: isotach.;
winter temperature mean: isocheim;
drive time: isochrone.;
frequency of hail storms: isochalaz.;
time of thawing: isotac.;
cost of travel time: isodopane.;
Read more at Wikipedia.org
|
Contact
