Struct EquidistantCylindricalProjection 

pub struct EquidistantCylindricalProjection { /* private fields */ }

Equidistant Cylindrical (Plate Carrée)

Classification: Conformal cylindrical

Available forms: Forward and inverse

Defined area: Global, but best used near the equator

Alias: eqc, plate_carrée, simple_cylindrical

Domain: 2D

Input type: Geodetic coordinates

Output type: Projected coordinates

Projection String

+proj=eqc

Usage

Because of the distortions introduced by this projection, it has little use in navigation or cadastral mapping and finds its main use in thematic mapping. In particular, the Plate Carrée has become a standard for global raster datasets, such as Celestia and NASA World Wind, because of the particularly simple relationship between the position of an image pixel on the map and its corresponding geographic location on Earth.

Special Cases of Cylindrical Equidistant Projection:

• Plain/Plane Chart: $0°$
• Simple Cylindrical: $0°$
• Plate Carrée: $0°$
• Ronald Miller—minimum overall scale distortion: $37°30’$
• E. Grafarend and A. Niermann: $42°$
• Ronald Miller—minimum continental scale distortion: $43°30’$
• Gall Isographic: $45°$
• Ronald Miller Equirectangular: $50°30’$
• E. Grafarend and A. Niermann minimum linear distortion: $61°7’$

Example

Example using EPSG 32662 (WGS84 Plate Carrée):

echo 2 47 | proj +proj=eqc +ellps=WGS84

Output: 222638.98 5232016.07

Example using Plate Carrée projection with true scale at latitude 30° and central meridian 90°W:

echo -88 30 | proj +proj=eqc +lat_ts=30 +lon_0=90w

Output: 192811.01 3339584.72

Parameters

• +lon_0 (Central meridian)
• +lat_0 (Latitude of origin)
• +lat_ts (Latitude of true scale)
• +x_0 (False easting)
• +y_0 (False northing)
• +ellps (Ellipsoid name)
• +R (Radius of the sphere)

Mathematical Definition

Forward projection:

$$x = \lambda \cos(\phi_{ts})$$ $$y = \phi - \phi_0$$

Inverse projection:

$$\lambda = x / \cos(\phi_{ts})$$ $$\phi = y + \phi_0$$

Further Reading

• Wikipedia
• Wolfram Mathworld

Trait Implementations

impl Clone for EquidistantCylindricalProjection

fn clone(&self) -> EquidistantCylindricalProjection

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl CoordinateStep for EquidistantCylindricalProjection

fn new(proj: Rc<RefCell<Proj>>) -> Self

Create a new Converter

fn forward<P: TransformCoordinates>(&self, p: &mut P)

forward conversion

fn inverse<P: TransformCoordinates>(&self, p: &mut P)

inverse conversion

impl Debug for EquidistantCylindricalProjection

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for EquidistantCylindricalProjection

fn eq(&self, other: &EquidistantCylindricalProjection) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl ProjectCoordinates for EquidistantCylindricalProjection

fn code(&self) -> i64

ESPG code for this projection

fn name(&self) -> &'static str

Projection name

fn names() -> &'static [&'static str]

Returns the list of canonical names for this projection. This is an associated function, similar to a static method.

fn datum_type() -> u8

get the datum type. Defaults to no datum

impl StructuralPartialEq for EquidistantCylindricalProjection