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).

arealScale(self) → float[source]¶

Areal scale factor at coordinate (λ,ϕ).

dxDlam(self) → float[source]¶

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

dxDphi(self) → float[source]¶

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

dyDlam(self) → float[source]¶

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

dyDphi(self) → float[source]¶

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

isValid(self) → bool[source]¶

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

meridianConvergence(self) → float[source]¶

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

meridianParallelAngle(self) → float[source]¶

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

meridionalScale(self) → float[source]¶

Meridional scale at coordinate (λ,ϕ).

parallelScale(self) → float[source]¶

Parallel scale at coordinate (λ,ϕ).

tissotSemimajor(self) → float[source]¶

Maximum scale factor.

tissotSemiminor(self) → float[source]¶

Minimum scale factor.