vec2dtransf (version 1.1.3)

calculateParameters: Calculate parameters

Description

Calculates transformation parameters from control points

Usage

calculateParameters(object)

Value

Modifies the original object

Arguments

object

Object of the class SimilarityTransformation or AffineTransformation

Author

German Carrillo

Details

If control points are provided, the 'calculateParameters' method must be used in order to calculate the transformation parameters. If there are more control points than required (2 for similarity and 3 for affine) Least Squares is applied and therefore residuals as well as Root Mean Square Error (RMSE) are available via 'getResiduals' and 'getRMSE' methods. Parameters can always be accessed via 'getParameters' method.

References

Iliffe, J. and Lott, R. Datums and map projections: For remote sensing, GIS and surveying. Section 4.5. pp.109-117, 2008.

UC Davis Soil Resource Laboratory. Case Study: Fixing Bad TIGER Line data with R and PostGIS. <URL: http://casoilresource.lawr.ucdavis.edu/drupal/node/433>

See Also

SimilarityTransformation, AffineTransformation, getResiduals, getRMSE, getParameters

Examples

data(control.points)
at <- AffineTransformation(control.points[2:5])
getParameters(at) # Still unknown 
calculateParameters(at)
getParameters(at) # Now there are parameters!