methods-cmds {ordr}

Functionality for classical multidimensional scaling objects

Description

These methods extract data from, and attribute new data to, objects of class "cmds_ord". This is a class introduced in this package to identify objects returned by cmdscale_ord(), which wraps stats::cmdscale().

Usage

## S3 method for class 'cmds_ord'
as_tbl_ord(x)

## S3 method for class 'cmds_ord'
recover_rows(x)

## S3 method for class 'cmds_ord'
recover_cols(x)

## S3 method for class 'cmds_ord'
recover_inertia(x)

## S3 method for class 'cmds_ord'
recover_coord(x)

## S3 method for class 'cmds_ord'
recover_conference(x)

## S3 method for class 'cmds_ord'
recover_aug_rows(x)

## S3 method for class 'cmds_ord'
recover_aug_cols(x)

## S3 method for class 'cmds_ord'
recover_aug_coord(x)

Arguments

x

An ordination object.

Value

The recovery generics ⁠recover_*()⁠ return core model components, distribution of inertia, supplementary elements, and intrinsic metadata; but they require methods for each model class to tell them what these components are.

The generic as_tbl_ord() returns its input wrapped in the 'tbl_ord' class. Its methods determine what model classes it is allowed to wrap. It then provides 'tbl_ord' methods with access to the recoverers and hence to the model components.

See Also

Other methods for eigen-decomposition-based techniques: methods-eigen, methods-factanal

Other models from the stats package: methods-cancor, methods-factanal, methods-kmeans, methods-lm, methods-prcomp, methods-princomp

Examples

# 'dist' object (matrix of road distances) of large American cities
class(UScitiesD)
print(UScitiesD)

# use multidimensional scaling to infer artificial planar coordinates
UScitiesD %>%
  cmdscale_ord(k = 2) %>%
  as_tbl_ord() %>%
  print() -> usa_mds

# recover (equivalent) matrices of row and column artificial coordinates
get_rows(usa_mds)
get_cols(usa_mds)

# augment ordination with point names
(usa_mds <- augment_ord(usa_mds))

# reorient biplot to conventional compass
usa_mds %>%
  negate_ord(c(1, 2)) %>%
  ggbiplot() +
  geom_cols_text(aes(label = name), size = 3) +
  ggtitle("MDS biplot of distances between U.S. cities")