Set Edge Label Attributes of Selected Edges

Set the attributes of selected edges, such as the label position.

Usage

set_edge_label_position(
  semPaths_plot,
  position_list = NULL,
  check_direction = TRUE
)

set_edge_label(semPaths_plot, label_list = NULL, check_direction = TRUE)

set_edge_label_bg(semPaths_plot, label_bg_list = NULL, check_direction = TRUE)

set_edge_label_size(
  semPaths_plot,
  label_size_list = NULL,
  how = c("ratio", "value"),
  check_direction = TRUE
)

Arguments

semPaths_plot

A qgraph::qgraph object generated by semPlot::semPaths, or a similar qgraph object modified by other semptools functions. It can also be a list of qgraph::qgraph objects, probably though not necessarily from a multigroup model. If it is a list of qgraph::qgraph objects, then the function will be applied to all the objects.

position_list

The new position. See 'Details' on how to set this argument. If a list of named list is used, the element for new position should be named new_position.

check_direction

If FALSE, the direction of an edge is ignored. For example, both y ~ x and x ~ y will affect y ~ x, x ~ y, and y ~~ x. Useful when we want to change an edge regardless of its direction and whether it is directional.

label_list

The new label. See 'Details' on how to set this argument. If a list of named list is used, the element for new label should be named new_label.

label_bg_list

The new background color. See 'Details' on how to set this argument. If a list of named list is used, the element for new background color should be named new_label_bg.

label_size_list

How the label sizes are to be changed. See 'Details' on how to set this argument. If a list of named list is used, the element for new background color should be named new_label_size.

how

How the width will be changed. If "ratio", then the new width is the original width multiplied by the supplied value. If "value", then the new width is set to the supplied value.

Details

Modify a qgraph::qgraph object generated by semPlot::semPaths and change the attributes of the edge label of selected edges.

Currently, the following attributes are supported:

• Edge label position.

• Edge label content.

• Edge label background color.

• Edge label size.

How to specify the values

There are three approach to specify the value.

First, the values can be a named vector of the values, the recommended approach. The name of an element should be the path as specified by lavaan::model.syntax or as appeared in lavaan::parameterEstimates(). For example, to change position of the edge label of the path regressing y on x, the name should be "y ~ x".

Second, the values can be specified by a list of named lists, each named list should have three named values: from, to, and the new value (name depends on the attribute). The value of the edge label of the edge from from to to will be set to this new value. For example, for set_edge_label_position(), list(list(from = "x1", to = "y", new_position = .2), list(from = "x2", to = "y", new_position = .7)) is equivalent to the named vector above.

The second approach is no longer recommended. It was supported for backward compatibility.

Third, the value can be a single value, which will be used to set the attribute of all edges.

Setting Edge Position

When setting the edge position, the value is the position. The mid-point of the edge is 0.5. The closer the value to 1, the closer the label to the left-hand-side node (y in this example). The closer the value to 0, the close the label to the right-hand-side node (x in this example). For example, c("y ~ x1" = .2, "y ~ x2" = .7) moves the path coefficient from x1 to y closer to x, and the path coefficient from x2 to y closer to y.

Setting Label Size

The function set_edge_label_size() works in two modes. With how = "ratio", the new label size is the original size multiplied by the supplied value. For example, if the value is 2, the size of a label is doubled. With how = "value", the new size is set to be equal to the supplied value. For example, if the value is 2, the size of a label is set to 2.

label positions for selected edges changed. If semPaths_plot is a list of qgraph::qgraph objects, then a list of processed qgraph::qgraph objects will be returned.

Examples

mod_pa <-
  'x1 ~~ x2
   x3 ~  x1 + x2
   x4 ~  x1 + x3
  '
fit_pa <- lavaan::sem(mod_pa, pa_example)
lavaan::parameterEstimates(fit_pa)[, c("lhs", "op", "rhs", "est", "pvalue")]
#>   lhs op rhs   est pvalue
#> 1  x1 ~~  x2 0.005  0.957
#> 2  x3  ~  x1 0.537  0.000
#> 3  x3  ~  x2 0.376  0.000
#> 4  x4  ~  x1 0.111  0.382
#> 5  x4  ~  x3 0.629  0.000
#> 6  x3 ~~  x3 0.874  0.000
#> 7  x4 ~~  x4 1.194  0.000
#> 8  x1 ~~  x1 0.933  0.000
#> 9  x2 ~~  x2 1.017  0.000
m <- matrix(c("x1",   NA,   NA,
                NA, "x3", "x4",
              "x2",   NA,   NA), byrow = TRUE, 3, 3)
p_pa <- semPlot::semPaths(fit_pa, whatLabels="est",
            style = "ram",
            nCharNodes = 0, nCharEdges = 0,
            layout = m)


# ==== set_edge_label_position ====

my_position_vector <- c(
  "x3 ~ x2" = .25,
  "x4 ~ x1" = .75
)
p_pa2v <- set_edge_label_position(
             p_pa,
             my_position_vector
           )
plot(p_pa2v)


# This approach is no longer recommended
my_position_list <- list(
                     list(
                       from = "x2",
                       to = "x3",
                       new_position = .25
                      ),
                     list(
                       from = "x1",
                       to = "x4",
                       new_position = .75)
                     )
p_pa2l <- set_edge_label_position(
             p_pa,
             my_position_list
           )
plot(p_pa2l)


# ==== set_edge_label ====

my_label_vector <- c(
  "x3 ~ x2" = "a",
  "x4 ~ x1" = "b"
)
p_pa3v <- set_edge_label(
             p_pa,
             my_label_vector
           )
plot(p_pa3v)


# This approach is no longer recommended
my_label_list <- list(
                     list(
                       from = "x2",
                       to = "x3",
                       new_label = "a"
                      ),
                     list(
                       from = "x1",
                       to = "x4",
                       new_position = "a")
                     )
p_pa3l <- set_edge_label(
             p_pa,
             my_label_list
           )
plot(p_pa3l)



# ==== set_edge_label_bg ====

my_label_bg_vector <- c(
  "x3 ~ x2" = "red",
  "x4 ~ x1" = "#00FF00"
)
p_pa4v <- set_edge_label_bg(
             p_pa,
             my_label_bg_vector
           )
plot(p_pa4v)


# This approach is no longer recommended
my_label_bg_list <- list(
                     list(
                       from = "x2",
                       to = "x3",
                       new_label_bg = "red"
                      ),
                     list(
                       from = "x1",
                       to = "x4",
                       new_label_bg = "#00FF00")
                     )
p_pa4l <- set_edge_label_bg(
             p_pa,
             my_label_bg_list
           )
plot(p_pa4l)



# ==== set_edge_label_size ====

my_label_size_vector <- c(
  "x3 ~ x2" = 2,
  "x4 ~ x1" = 3
)
p_pa5v <- set_edge_label_size(
             p_pa,
             my_label_size_vector
           )
plot(p_pa5v)


# This approach is no longer recommended
my_label_size_list <- list(
                     list(
                       from = "x2",
                       to = "x3",
                       new_label_size = 2
                      ),
                     list(
                       from = "x1",
                       to = "x4",
                       new_label_size = 3)
                     )
p_pa5l <- set_edge_label_size(
             p_pa,
             my_label_size_list
           )
plot(p_pa5l)