Class: QgsProjectionFactors

Contains various cartographic properties, such as scale factors, angular distortion and meridian convergence.

Added in version 3.20.

Methods

angularDistortion

Angular distortion at coordinate (λ,ϕ).

arealScale

Areal scale factor at coordinate (λ,ϕ).

dxDlam

Partial derivative ∂x/∂λ of coordinate (λ,ϕ).

dxDphi

Partial derivative ∂x/∂ϕ of coordinate (λ,ϕ).

dyDlam

Partial derivative ∂y/∂λ of coordinate (λ,ϕ).

dyDphi

Partial derivative ∂y/∂ϕ of coordinate (λ,ϕ).

isValid

Returns True if the factors are valid, or False if they could not be calculated.

meridianConvergence

Meridian convergence (in degrees) at coordinate (λ,ϕ).

meridianParallelAngle

Meridian/parallel angle (in degrees), θ′, at coordinate (λ,ϕ).

meridionalScale

Meridional scale at coordinate (λ,ϕ).

parallelScale

Parallel scale at coordinate (λ,ϕ).

tissotSemimajor

Maximum scale factor.

tissotSemiminor

Minimum scale factor.

class qgis.core.QgsProjectionFactors[source]

Bases: object

angularDistortion(self) float[source]

Angular distortion at coordinate (λ,ϕ).

Return type:

float

arealScale(self) float[source]

Areal scale factor at coordinate (λ,ϕ).

Return type:

float

dxDlam(self) float[source]

Partial derivative ∂x/∂λ of coordinate (λ,ϕ).

Return type:

float

dxDphi(self) float[source]

Partial derivative ∂x/∂ϕ of coordinate (λ,ϕ).

Return type:

float

dyDlam(self) float[source]

Partial derivative ∂y/∂λ of coordinate (λ,ϕ).

Return type:

float

dyDphi(self) float[source]

Partial derivative ∂y/∂ϕ of coordinate (λ,ϕ).

Return type:

float

isValid(self) bool[source]

Returns True if the factors are valid, or False if they could not be calculated.

Return type:

bool

meridianConvergence(self) float[source]

Meridian convergence (in degrees) at coordinate (λ,ϕ). Sometimes also described as grid declination.

Return type:

float

meridianParallelAngle(self) float[source]

Meridian/parallel angle (in degrees), θ′, at coordinate (λ,ϕ).

Return type:

float

meridionalScale(self) float[source]

Meridional scale at coordinate (λ,ϕ).

Return type:

float

parallelScale(self) float[source]

Parallel scale at coordinate (λ,ϕ).

Return type:

float

tissotSemimajor(self) float[source]

Maximum scale factor.

Return type:

float

tissotSemiminor(self) float[source]

Minimum scale factor.

Return type:

float