Returns a new array [x, y] (typically in pixels) representing the projected point of the given point. The point must be specified as a two-element array [longitude, latitude] in degrees. May return null if the specified point has no defined projected position, such as when the point is outside the clipping bounds of the projection.
A point specified as a two-dimensional array [longitude, latitude] in degrees.
Returns the projection’s current angle, which defaults to 0°.
Sets the projection’s post-projection planar rotation angle to the specified angle in degrees and returns the projection.
The new rotation angle of the projection.
Returns the current center of the projection, which defaults to ⟨0°,0°⟩.
Sets the projection’s center to the specified center, a two-element array of longitude and latitude in degrees and returns the projection. The default is ⟨0°,0°⟩.
A point specified as a two-dimensional array [longitude, latitude] in degrees.
Returns the current clip angle which defaults to null.
null switches to antimeridian cutting rather than small-circle clipping.
Sets the projection’s clipping circle radius to the specified angle in degrees and returns the projection. If angle is null, switches to antimeridian cutting rather than small-circle clipping.
Returns the current viewport clip extent which defaults to null.
Sets the projection’s viewport clip extent to the specified bounds in pixels and returns the projection. The extent bounds are specified as an array [[x₀, y₀], [x₁, y₁]], where x₀ is the left-side of the viewport, y₀ is the top, x₁ is the right and y₁ is the bottom. If extent is null, no viewport clipping is performed.
Sets the projection’s scale and translate to fit the specified GeoJSON object in the center of the given extent. The extent is specified as an array [[x₀, y₀], [x₁, y₁]], where x₀ is the left side of the bounding box, y₀ is the top, x₁ is the right and y₁ is the bottom. Returns the projection.
A convenience method for projection.fitSize where the width is automatically chosen from the aspect ratio of object and the given constraint on height.
A convenience method for projection.fitExtent where the top-left corner of the extent is [0, 0].
A convenience method for projection.fitSize where the height is automatically chosen from the aspect ratio of object and the given constraint on width.
Optional invertReturns a new array [longitude, latitude] in degrees representing the unprojected point of the given projected point. May return null if the specified point has no defined projected position, such as when the point is outside the clipping bounds of the projection.
The projected point, specified as a two-element array [x, y] (typically in pixels).
Returns the current cartesian clipping function. Post-clipping occurs on the plane, when a projection is bounded to a certain extent such as a rectangle.
Sets the projection’s cartesian clipping to the specified function and returns the projection.
Returns the projection’s current resampling precision which defaults to square root of 0.5. This value corresponds to the Douglas–Peucker distance.
Sets the threshold for the projection’s adaptive resampling to the specified value in pixels and returns the projection. This value corresponds to the Douglas–Peucker distance.
A numeric value in pixels to use as the threshold for the projection’s adaptive resampling.
Returns the current spherical clipping function. Pre-clipping occurs in geographic coordinates. Cutting along the antimeridian line, or clipping along a small circle are the most common strategies.
Sets the projection’s spherical clipping to the specified function and returns the projection. Pre-clipping occurs in geographic coordinates. Cutting along the antimeridian line, or clipping along a small circle are the most common strategies.
Returns true if x-reflection is enabled, which defaults to false.
Sets whether or not the x-dimension is reflected (negated) in the output.
Whether or not the x-dimension is reflected (negated) in the output.
Returns true if y-reflection is enabled, which defaults to false.
Sets whether or not the y-dimension is reflected (negated) in the output.
Whether or not the y-dimension is reflected (negated) in the output.
Returns the current rotation [lambda, phi, gamma] specifying the rotation angles in degrees about each spherical axis. (These correspond to yaw, pitch and roll.) which defaults [0, 0, 0].
Sets the projection’s three-axis rotation to the specified angles, which must be a two- or three-element array of numbers.
A two- or three-element array of numbers [lambda, phi, gamma] specifying the rotation angles in degrees about each spherical axis. (These correspond to yaw, pitch and roll.) If the rotation angle gamma is omitted, it defaults to 0.
Returns the current scale factor; the default scale is projection-specific.
The scale factor corresponds linearly to the distance between projected points; however, absolute scale factors are not equivalent across projections.
Sets the projection’s scale factor to the specified value and returns the projection. The scale factor corresponds linearly to the distance between projected points; however, absolute scale factors are not equivalent across projections.
Scale factor to be used for the projection; the default scale is projection-specific.
Returns a projection stream for the specified output stream. Any input geometry is projected before being streamed to the output stream. A typical projection involves several geometry transformations: the input geometry is first converted to radians, rotated on three axes, clipped to the small circle or cut along the antimeridian, and lastly projected to the plane with adaptive resampling, scale and translation.
An input stream
Returns the current translation offset which defaults to [480, 250] and places ⟨0°,0°⟩ at the center of a 960×500 area. The translation offset determines the pixel coordinates of the projection’s center.
Sets the projection’s translation offset to the specified two-element array [tx, ty] and returns the projection. The translation offset determines the pixel coordinates of the projection’s center. The default translation offset places ⟨0°,0°⟩ at the center of a 960×500 area.
A two-element array [tx, ty] specifying the translation offset. The default translation offset of defaults to [480, 250] places ⟨0°,0°⟩ at the center of a 960×500 area.
A Geographic Projection to transform spherical polygonal geometry to planar polygonal geometry. D3 provides implementations of several classes of standard projections:
For many more projections, see d3-geo-projection. You can implement custom projections using d3.geoProjection or d3.geoProjectionMutator.