# cootrans: Tool for transforming local metric coordinates In recexcavAAR: 3D Reconstruction of Archaeological Excavations

## Description

This function transforms local metric coordinates to absolute coordinates of referenced systems by use of a two dimensional four parameter Helmert transformation. This function does not cover the transformation of three dimensional points or transformation between two different datums.

## Usage

 ```1 2``` ```cootrans(pair_matrix, pm_column, data_matrix, dm_column, checking = FALSE, checkplot = TRUE) ```

## Arguments

 `pair_matrix` data.frame or matrix with pairs of local and corresponding absolute coordinates (Minimum two!) `pm_column` vector with numerical index of the columns in order: local x-value, local y-value, absolute x-value, absolute y-value `data_matrix` data.frame with local x- and y-values which schould be transformed. `dm_column` vector with numerical index of the columns in order: local x-value, local y-value. `checking` boolean switch to turn on the checking ability. Default: FALSE. If TRUE showes combined coordinate plots with indexed points and alters return of function. `checkplot` boolean switch to turn off the checking plot. Default: TRUE. Only matters if checking == TRUE.

## Value

Original data.frame with additional columns containing the absolute x- and y-coordinates. In case of 'checking = TRUE' returns pair_matrix data.frame with additional columns of scale and rotation arc in degrees.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16``` ```coord_data <- data.frame( loc_x = c(1,3,1,3), loc_y = c(1,1,3,3), abs_x = c(107.1,107,104.9,105), abs_y = c(105.1,107,105.1,106.9) ) data_table <- data.frame( x = c(1.5,1.2,1.6,2), y = c(1,5,2.1,2), type = c("flint","flint","pottery","bone") ) new_frame <- cootrans(coord_data, c(1,2,3,4), data_table, c(1,2)) check_data <- cootrans(coord_data, c(1,2,3,4), data_table, c(1,2), checking = TRUE) ```

recexcavAAR documentation built on May 1, 2019, 6:48 p.m.