# fixLMmirror: estimate missing landmarks from their bilateral counterparts In Morpho: Calculations and Visualisations Related to Geometric Morphometrics

 fixLMmirror R Documentation

## estimate missing landmarks from their bilateral counterparts

### Description

estimate missing landmarks from their bilateral counterparts

### Usage

``````fixLMmirror(x, pairedLM, ...)

## S3 method for class 'array'
fixLMmirror(x, pairedLM, ...)

## S3 method for class 'matrix'
fixLMmirror(x, pairedLM, ...)
``````

### Arguments

 `x` a matrix or an array containing landmarks (3D or 2D) `pairedLM` a k x 2 matrix containing the indices (rownumbers) of the paired LM. E.g. the left column contains the lefthand landmarks, while the right side contains the corresponding right hand landmarks. `...` additional arguments

### Details

the configurations are mirrored and the relabled version is matched onto the original using a thin-plate spline deformation. The missing landmark is now estimated using its bilateral counterpart. If one side is completely missing, the landmarks will be mirrored and aligned by the unilateral landmarks.

### Value

a matrix or array with fixed missing bilateral landmarks.

### Note

in case both landmarks of a bilateral pair are missing a message will be issued. As well if there are missing landmarks on the midsaggital plane are detected.

### Examples

``````data(boneData)
left <- c(4,6,8)
## determine corresponding Landmarks on the right side:
# important: keep same order
right <- c(3,5,7)
pairedLM <- cbind(left, right)
exampmat <- boneLM[,,1]
exampmat[4,] <- NA #set 4th landmark to be NA
fixed <- fixLMmirror(exampmat, pairedLM=pairedLM)
## Not run:
deformGrid3d(fixed, boneLM[,,1],ngrid=0)
## result is a bit off due to actual asymmetry

## End(Not run)
## example with one side completely missing
oneside <- boneLM[,,1]
oneside[pairedLM[,1],] <- NA
onesidefixed <- fixLMmirror(oneside,pairedLM)
## Not run:
deformGrid3d(onesidefixed, boneLM[,,1],ngrid=0)
## result is a bit off due to actual asymmetry

## End(Not run)
``````

Morpho documentation built on June 22, 2024, 7:19 p.m.