List of Projections for Use with WorldMap - Maple Programming Help

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List of Projections for Use with WorldMap

 

Description

Geographic

Cassini

Mercator

TransverseMercator

MillerCylindrical

CylindricalEqualArea

LambertAzimuthalEqualArea

AzimuthalEquidistant

VanderGrinten

Bonne

Bottomley

Werner

Sinusoidal

Robinson

WinkelTripel

Globe

Description

• 

The Display command of the WorldMap object can display maps of the world using various projections by specifying the projection=proj keyword option.

• 

Some projections accept additional parameters for the central meridian (λ0) and/or the standard parallel (φ1).

• 

Examples in all sections below use the WorldMap object with no point stored:

m:=DataSets:-Builtin:-WorldMap();

mPLOT...A map of the worldprojection: MillerCylindrical

(1)

Geographic

• 

The Geographic projection directly maps longitude and latitude pairs to x and y coordinates in the map.

• 

It is a special case of the Equirectangular projection with the standard parallel (φ1) equal to 0 degrees.

Display(m,projection=Geographic);

Cassini

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The Cassini projection is the transverse aspect of the Geographic projection.

• 

The Cassini projection can accept an additional parameter for the central meridian (λ0).

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If no parameter is specified, the resulting projection is equivalent to Cassini(0).

Display(m,projection=Cassini);

Mercator

• 

The Mercator projection is a conformal cylindrical map projection which is widely used for nautical purposes.

• 

It greatly exaggerates areas far from the equator, and the poles are projected to infinity, so the map must be truncated near the poles.

Display(m,projection=Mercator);

TransverseMercator

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The TransverseMercator projection is the transverse aspect of the Mercator projection.

• 

It delivers accurate scales near the central meridian.

Display(m,projection=TransverseMercator);

MillerCylindrical

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The MillerCylindrical projection is a compromise cylindrical map projection that is intended to look similar to the Mercator projection while displaying the poles.

• 

The MillerCylindrical projection is the default projection used by the Display command.

Display(m,projection=MillerCylindrical);

CylindricalEqualArea

• 

The CylindricalEqualArea projection is a family of cylindrical and equal area projections.

• 

The general CylindricalEqualArea projection can accept an additional parameter for the standard parallel (φ1).

• 

If no parameter is specified, the resulting projection is the HoboDyer projection.

• 

Supported special cases include LambertCylindricalEqualArea, Behrmann, SmythEqualSurface, TrystanEdwards, HoboDyer, GallPeters, and Balthasart. The value of the standard parallel for these projections is listed in the table below.

Projections

φ1

LambertCylindricalEqualArea

0

Behrmann

30

SmythEqualSurface

37 + 4 / 60 + 17 / 3600 (that is, 37° 4' 17")

TrystanEdwards

37.4

HoboDyer

37.5

GallPeters

45

Balthasart

50

Display(m,projection=CylindricalEqualArea(37.5));

LambertAzimuthalEqualArea

• 

The LambertAzimuthalEqualArea projection maps the earth onto a disk, and it preserves areas of all regions.

• 

The LambertAzimuthalEqualArea projection can accept two parameters for the central meridian (λ0) and the standard parallel (φ1).

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If no parameter is specified, the resulting projection is the equatorial aspect of the LambertAzimuthalEqualArea projection.

• 

The point (λ0,φ1) becomes the center of the projected map.

Display(m,projection=LambertAzimuthalEqualArea(20.4, -15));

AzimuthalEquidistant

• 

The AzimuthalEquidistant projection can accept two parameters for the central meridian (λ0) and the standard parallel (φ1).

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If no parameter is specified, the resulting projection is the north pole aspect of the AzimuthalEquidistant projection.

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The point (λ0,φ1) becomes the center of the projected map.

• 

Distances from the center to all other points are preserved.

Display(m,projection=AzimuthalEquidistant(0,90));

VanderGrinten

• 

The VanderGrinten projection is a compromise projection that maps the earth onto a circle. The polar regions exhibit great distortions.

• 

It was used by the National Geographic Society from 1922 to 1988.

Display(m,projection=VanderGrinten);

Bonne

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The Bonne projection is a pseudoconical equal area projection which is an intermediate between the Werner projection and the Sinusoidal projection.

• 

The Bonne projection can accept two parameters for the central meridian (λ0) and the standard parallel (φ1).

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If no parameter is specified, the resulting projection is equivalent to Bonne(0,45).

Display(m,projection=Bonne(0,45));

Bottomley

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The Bottomley projection is a pseudoconical equal area projection that is designed as a better looking alternative to the Bonne projection.

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The Bottomley projection can also be seen as an intermediate between the Werner projection and the Sinusoidal projection.

• 

The Bottomley projection can accept an additional parameter for the standard parallel (φ1).

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If no parameter is specified, the resulting projection is equivalent to Bottomley(45).

Display(m,projection=Bottomley(45));

Werner

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The Werner projection is a limiting case of both the Bonne and the Bottomley projection.

• 

It is equivalent to Bonne(0,90) and Bottomley(90).

Display(m,projection=Werner);

Sinusoidal

• 

The Sinusoidal projection is also a limiting case of both the Bonne and the Bottomley projection.

• 

The Sinusoidal projection can accept an additional parameter for the central meridian (λ0).

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The Sinusoidal(0) projection is equivalent to Bottomley(0). The Sinusoidal(λ0) projection is equivalent to Bonne(λ0, 0).

• 

If no parameter is specified, the resulting projection is equivalent to Sinusoidal(0).

Display(m,projection=Sinusoidal(-12));

Robinson

• 

The Robinson projection is a pseudocylindrical compromise projection that is designed to produce a nice looking map for the entire world.

• 

It was used by the National Geographic Society from 1988 to 1998.

Display(m,projection=Robinson);

WinkelTripel

• 

The WinkelTripel projection is a pseudoazimuthal compromise projection that tries to minimize area, direction, and distance distortions all at the same time.

• 

It has been used by the National Geographic Society since 1998.

Display(m,projection=WinkelTripel);

Globe

• 

The Globe projection displays a 3-D plot of the earth as a sphere.

Display(m,projection=Globe);