sv_force: SHAP Force Plot

In shapviz: SHAP Visualizations

SHAP Force Plot

Description

Creates a force plot of SHAP values of one observation. If multiple observations are selected, their SHAP values and predictions are averaged.

Usage

sv_force(object, ...)

## Default S3 method:
sv_force(object, ...)

## S3 method for class 'shapviz'
sv_force(
  object,
  row_id = 1L,
  max_display = 6L,
  fill_colors = c("#f7d13d", "#a52c60"),
  format_shap = getOption("shapviz.format_shap"),
  format_feat = getOption("shapviz.format_feat"),
  contrast = TRUE,
  bar_label_size = 3.2,
  show_annotation = TRUE,
  annotation_size = 3.2,
  ...
)

## S3 method for class 'mshapviz'
sv_force(
  object,
  row_id = 1L,
  max_display = 6L,
  fill_colors = c("#f7d13d", "#a52c60"),
  format_shap = getOption("shapviz.format_shap"),
  format_feat = getOption("shapviz.format_feat"),
  contrast = TRUE,
  bar_label_size = 3.2,
  show_annotation = TRUE,
  annotation_size = 3.2,
  ...
)

Arguments

object	An object of class "(m)shapviz".
...	Arguments passed to ggfittext::geom_fit_text(). For example, size = 9 will use fixed text size in the bars and size = 0 will altogether suppress adding text to the bars.
row_id	Subset of observations to plot, typically a single row number. If more than one row is selected, SHAP values are averaged, and feature values are shown only when they are unique.
max_display	Maximum number of features (with largest absolute SHAP values) should be plotted? If there are more features, they will be collapsed to one feature. Set to Inf to show all features.
fill_colors	A vector of exactly two fill colors: the first for positive SHAP values, the other for negative ones.
format_shap	Function used to format SHAP values. The default uses the global option shapviz.format_shap, which equals to function(z) prettyNum(z, digits = 3, scientific = FALSE) by default.
format_feat	Function used to format numeric feature values. The default uses the global option shapviz.format_feat, which equals to function(z) prettyNum(z, digits = 3, scientific = FALSE) by default.
contrast	Logical flag that detemines whether to use white text in dark arrows. Default is TRUE.
bar_label_size	Size of text used to describe bars (via ggrepel::geom_text_repel()).
show_annotation	Should "f(x)" and "E(f(x))" be plotted? Default is TRUE.
annotation_size	Size of the annotation text (f(x)=... and E(f(x))=...).

Details

f(x) denotes the prediction on the SHAP scale, while E(f(x)) refers to the baseline SHAP value.

Value

An object of class "ggplot" (or "patchwork") representing a force plot.

Methods (by class)

• sv_force(default): Default method.

• sv_force(shapviz): SHAP force plot for object of class "shapviz".

• sv_force(mshapviz): SHAP force plot for object of class "mshapviz".

See Also

sv_waterfall()

Examples

dtrain <- xgboost::xgb.DMatrix(
  data.matrix(iris[, -1]), label = iris[, 1], nthread = 1
)
fit <- xgboost::xgb.train(data = dtrain, nrounds = 20, nthread = 1)
x <- shapviz(fit, X_pred = dtrain, X = iris[, -1])
sv_force(x)
sv_force(x, row_id = 65, max_display = 3, size = 9, fill_colors = 4:5)

# Aggregate over all observations with Petal.Length == 1.4
sv_force(x, row_id = x$X$Petal.Length == 1.4)

shapviz documentation built on Sept. 14, 2024, 5:07 p.m.