bu2mm: Scale Blender data (Blender Units) into millimeter

In axzinker/blenderFace: Collection of functions to process blender measured facial movement data

Scale Blender data (Blender Units) into millimeter

Description

The function rescales specific columns of a data frame according to a scale factor. For example, the scale factor can be the diameter of a glue dot measured in Blender. The columns are rescaled accordingly to represent millimeter instead of Blender Units as measurement unit. For a detailed description of the rescaling procedure refere to the vignette.

Usage

bu2mm(data, colNames, colNameSubj, scaleFactor, rwMeasure = 8, verbose = FALSE)

Arguments

data	Data frame containig the columns which should be rescaled. Remaining colums will be returned untouched. The data frame may contain many subjects, e.g., as generated by the function concatBlenderFiles.
colNames	Character vector with names of the columns of the data data-frame for which the data should be rescaled.
colNameSubj	Character vector with a single value containig the name of the subject column of the data data-frame.
scaleFactor	This factor could be either given as a column name for a numeric column attached to the data dataframe, or as separate numeric vector. The column or vector should contain the values of an object with known size (e.g., a glue dot diameter) measured in blender for each subject in the data data-frame. The scaleFactor vector must contain a scale value for each subject in the data data-frame. The sorting of subjects in data data-frame and the sorting of the scaleFactor vector must be the same.
rwMeasure	Optional. Size of an object measured in the desired outcome measurement (e.g., in millimeter). This value is used to rescale the data columns. The default value for this parameter is the diameter of a glue dot (8 millimeter).
verbose	Logical value. If TRUE, the function provides verbose console output.

Value

Data frame with columns rescaled to millimeter.

Author(s)

Axel Zinkernagel [e-mail]

Examples

# Load the file "Blender_Scalingdata.csv"
scaledata <- read.csv(system.file("extdata", "Blender_Scalingdata.csv", 
                      package = "blenderFace"), header = TRUE, sep =",")
# Be sure to have the data sorted by subjects
scaledata <- scaledata[with(scaledata, order(scaledata$subject)), ]

# Determin the dataframe columns which should be scaled:
names(rawdata)
# -> Frame, Stimulustype and subject should not be scaled -> removed for variable colNames
colNames <- c("A7_x",  "A7_y",  "A7_z",  "A8_x",  "A8_y",  "A8_z",  
             "BL2_x", "BL2_y", "BL2_z", "BL4_x", "BL4_y", "BL4_z", 
             "BL5_x", "BL5_y", "BL5_z", "BL7_x", "BL7_y", "BL7_z",       
             "BR2_x", "BR2_y", "BR2_z", "BR4_x", "BR4_y", "BR4_z", 
             "BR5_x", "BR5_y", "BR5_z", "BR7_x", "BR7_y", "BR7_z", 
             "CL4_x", "CL4_y", "CL4_z", "CL7_x", "CL7_y", "CL7_z",       
             "CR4_x", "CR4_y", "CR4_z", "CR7_x", "CR7_y", "CR7_z", 
             "DL2_x", "DL2_y", "DL2_z", "DR2_x", "DR2_y", "DR2_z")

# To not overwrite existing data, use a new data frame 
# (dataSmm means data scaled in millimeter)
dataSmm <- bu2mm(data = rawdata, colNames = colNames, colNameSubj = "subject", 
                 scaleFactor = scaledata$GlueDotDiameter, rwMeasure = 8, 
                 verbose = TRUE)

axzinker/blenderFace documentation built on Feb. 27, 2024, 10:25 a.m.