# makeTria: Reshapes an unordered covariance/correlation matrix into... In eatTools: Miscellaneous Functions for the Analysis of Educational Assessments

 makeTria R Documentation

## Reshapes an unordered covariance/correlation matrix into triangular shape

### Description

Function is mainly used for `eatAnalysis::wtdHetcor` function from the `eatAnalysis` package (https://github.com/beckerbenj/eatAnalysis/) and the `eatModel::q3FromRes` function in the `eatModel` package: Triangular covariance/correlation matrices are tidily reshaped.

### Usage

``makeTria (dfr)``

### Arguments

 `dfr` A data frame consisting of a row name column and a square matrix.

### Details

covariance/correlation matrices which are inherently symmetrical are often displayed in a space-saving manner by only showing the upper or lower triangular part, omitting the symmetrical counterpart. In R, covariance/correlation matrices tend to be displayed with their upper and lower halves. Whereas `lower.tri` and `upper.tri` allows to replace upper or lower half with `NA`s, the triangular shape could then be lost if the covariance/correlation matrix was provided in a long format and reshaped afterwards. `makeTria` sorts rows and colums appropriately to provide triangular shape if redundant entries are replaced by NA. Please note that the functions expects row names in the first column of the input data.frame.

data frame.

### Examples

``````dfr <- data.frame ( vars = paste0("var", 2:4), matrix(c(1:3, NA, NA, 5, 4,NA,6),
nrow=3, ncol=3, dimnames=list(NULL, paste0("var", 1:3))))
makeTria(dfr)
``````

eatTools documentation built on May 29, 2024, 6:03 a.m.