R/plot_explainBART.R

Defines functions plot.ExplainBART

Documented in plot.ExplainBART

#' A Function for Visualizing the Shapley Values of BART Models
#'
#' The \code{plot.ExplainBART} function provides various visualization methods for Shapley values. 
#' It is designed to visualize \code{ExplainBART} class objects, which contain Shapley values computed from models estimated using the \code{bart} function from the \pkg{dbarts} or the \code{wbart}/\code{gbart} functions from \pkg{BART}.
#' The values and format used in the graph are determined based on the input parameters.
#'
#' @param x An \code{ExplainBART} class object containing the Shapley values of the BART model.
#' @param average  Input the reference value for calculating the mean of the object's \code{phi} list.
#' \code{"obs"} represents abind the average based on observations (#post by #variable),
#' while \code{"post"} represents the average based on posterior samples (#obs by #variable).
#' If \code{"both"} is entered, calculations are performed based on both observation and posterior sample criteria.
#' If no value is specified, "both" is used as the default.
#' @param title The title of the plot, with a default value of \code{NULL}.
#' @param type \code{"bar"} represents a bar chart that includes the average contribution of each variable,
#'  while \code{"bee"} represents a summary plot, allowing you to determine the graph's format.
#' @param num_post To check the contribution of variables for a single posterior sample,
#'  enter a value within the number of posterior samples.
#' @param adjust The default value is \code{FALSE}.
#' Enter \code{TRUE} to check the Shapley values adjusted based on the model's average contribution.
#' @param plot.flag If \code{average = "obs"}, the quantile interval of each variable's is provided by default.
#' @param probs Enter the probability for the quantile interval. The default value is \code{0.95}.
#' @param ... Additional arguments to be passed
#' @return The plot is returned based on the specified option.: 
#' \item{out}{If average is \code{"obs"} or \code{"post"}, a bar plot or summary plot is generated based on the selected averaging criterion. If average is `"both"`, a boxplot is displayed to
#'show the distribution of Shapley values computed using both criteria. If adjust is \code{TRUE}, the adjusted Shapley values are displayed.
#' If \code{num_post} is specified, a bar plot or summary plot for the selected posterior sample is generated.}
#' @examples
#' \donttest{
#' ## Friedman data
#' set.seed(2025)
#' n <- 200
#' p <- 5
#' X <- data.frame(matrix(runif(n * p), ncol = p))
#' y <- 10 * sin(pi* X[ ,1] * X[,2]) +20 * (X[,3] -.5)^2 + 10 * X[ ,4] + 5 * X[,5] + rnorm(n)
#' 
#'## Using dbarts 
#'model <- dbarts::bart (X,y, keeptrees = TRUE, ndpost = 200)
#'
#'# prediction wrapper function
#'pfun <- function (object, newdata) {
#'predict(object, newdata)
#'}
#'
#'# Calculate shapley values
#'model_exp <-  Explain  ( model, X = X,  pred_wrapper =  pfun )
#'
#'# Distribution of Shapley values (boxplot) 
#'# computed based on observation and posterior sample criteria
#'plot(model_exp,average = "both" ) 
#'
#'# Barplot based on observation criteria
#'plot(model_exp,average = "obs",type ="bar",probs = 0.95)
#'
#'# Barplot based on posterior sample
#'plot(model_exp,average = "post",type ="bar" )
#'
#'# Summary plot based on posterior sample
#'plot(model_exp,average = "post",type ="bees" )
#'
#'# Summary plot of the 100th posterior sample
#'plot(model_exp,average = "post",type ="bees",num_post = 100) 
#'
#'# Barplot of the adjusted baseline
#'plot(model_exp, type ="bar",  adjust= TRUE )
#'}
#' @aliases plot
#' @importFrom dplyr n
#' @importFrom dplyr mutate
#' @export

plot.ExplainBART <- function(x, average=NULL, type=NULL, num_post=NULL,
                             plot.flag=TRUE, adjust=FALSE, probs=0.95, title=NULL,...){
 
  
  if (!inherits(x, "ExplainBART") ) {
    message("The input object must be of class 'ExplainBART'.")
    return(invisible(NULL))
  } else if (missing(x) ) {
    stop("The object containing the Shapley values of models obtained from the 'Explain' function is missing.")
    return(invisible(NULL))
  }
  
   object <- x 
  value <- variable <- n <- Average_re <-  0 
  feature_names <- names(object$newdata)
  factor_names <- object$factor_names
  
  
  if (is.null(average)){
    
    warning("By default, a plot of type 'both' is printed.\n",
            "If you want to calculate the average based on observations, enter 'obs'.\n",
            "If you want to calculate the average based on the posterior sample, enter 'post'.\n",
            "To compare the results based on observation and posterior sample, enter 'both'.",call. = FALSE)
    
    average <- "both"
  } 

  length_cate <- NULL
  
  for (i in factor_names){
     if(length(which(str_detect(feature_names,i))) >= 1 ){
       length_cate <- c(length_cate, feature_names[which(str_detect(feature_names,i))] )
     }
  }

  if(isTRUE(adjust)) {
    # Compute mean and variance of posterior samples
    acomb <- function(...) abind(..., along = 3)
    phis.stats <- foreach(i = feature_names, .combine = "acomb") %do% {
      cbind(rowMeans(object$phis[[i]]), apply( object$phis[[i]], MARGIN = 1, FUN = var))
    }
    for (i in seq_len(dim(phis.stats)[1L])) {  # loop through each observation
      err <- object$fx - sum(phis.stats[i, 1L, ]) - object$fnull
      if( max(phis.stats[i, 2L, ])==0) {  v <- 0  } else {
        v <- (phis.stats[i, 2L, ] / max(phis.stats[i, 2L, ])) * 1e6 }
      adj <- err[i] * (v - (v * sum(v)) / (1 + sum(v)))
      phis.stats[i, 1L, ] <- phis.stats[i, 1L, ] + adj  # adjust Shapley estimate
    }
    phis_adj <- phis.stats[, 1L, ]

    phis_adj <- as.data.frame(phis_adj)
    names (phis_adj) <- feature_names


    for ( i in length_cate){
      temp_i <- which ( object$newdata[,i] !=1)
      phis_adj[temp_i,i] <- NA
    }

    local_obs <- long_data (phis_adj, normalize = TRUE, absolute = TRUE)

    if (isTRUE(type =="bar")| is.null(type)){

      Local_mean <- as.data.frame(abs(phis_adj))
      # bar plot
      sample_summary <- local_obs$long %>% filter (is.na(value)==FALSE)%>%
        select(c("variable", "value")) %>% group_by(variable) %>% mutate (n=n()) %>%
        select(c("variable","n")) %>% distinct(.keep_all = TRUE)

      sample_zero <- local_obs$long %>% filter(is.na (value)==FALSE)%>%
        select(c("variable", "value"))%>% group_by(variable) %>% mutate (n=n())%>%
        filter(value==0) %>% mutate (zero =n()) %>% distinct(.keep_all = TRUE) %>% select(c("variable", "zero"))

      sample_summary <- left_join(sample_summary, sample_zero, by = "variable" )
      sample_summary [which(is.na(sample_summary$zero)), "zero"] = 0

      sample_summary$percent <- paste0(sprintf("%.1f", round(sample_summary$zero/sample_summary$n*100, 1)) ,"%")

      out <- bar_plot(Local_mean,probs = NULL, plot.flag = FALSE , title)

      ymin <- (- diff(range(out$coordinates$limits$y,na.rm = TRUE)) * 0.02)

      out <- out +
        annotate("text",x= sample_summary$variable, y =  ymin,
                 hjust = 1, label = sample_summary$percent , size = 3.5)
      print(out)

    } else if (isTRUE( type == "bees")){
      #  summary plot
      out <- summary_plot (local_obs,title )
      print(out)
}


} else{
  
   if (isTRUE(average =="obs")){

      for( i in length_cate) {
        temp_i <- which(object$newdata[,i] !=1)
        object$phis [[i]][temp_i,] <- NA
      }


      # Average based on observation= #post by #variable
      obs_mean_shap <- foreach(i = 1:length(object$ phis), .combine = 'cbind') %do% {
        apply(object$phis[[i]], 2, function(x) {mean(abs(x),na.rm = TRUE)})
      }
      colnames(obs_mean_shap) <- names(object$phis)


      out <- bar_plot (obs_mean_shap, probs, plot.flag= T,title )

      if ( isTRUE(type =="bees") ) {
        message("In Average based on observation,\n a barplot is also provided by entering type='bees'.")
      }

      print (out)


  } else if ( isTRUE( average =="post") ){

    if (is.null(num_post)){


          # Average based on posterior sample = #obs by #variable
          post_mean_shap <- foreach(i = 1:length(object$phis), .combine = 'cbind') %do% {
            apply(object$phis[[i]], 1, function(x) {mean(x)})
            }
          colnames(post_mean_shap) <- names(object$phis)

          for (i in length_cate){
            temp_i <- which (object$newdata[,i] !=1)
            post_mean_shap[temp_i,i] <- NA
          }

      # Change data format & mean values => local_total is List
      local_total <- long_data(post_mean_shap, normalize = TRUE, absolute = TRUE)

      if (isTRUE(type =="bar")| is.null (type)){
        # bar plot
        Local_mean <- as.data.frame(abs(post_mean_shap))

        sample_summary <- local_total$long %>% filter(is.na(value)==FALSE)%>%
          select(c("variable", "value")) %>% group_by(variable) %>% mutate (n=n()) %>%
          select (c("variable","n")) %>% distinct(.keep_all = TRUE)

        sample_zero <- local_total$ long %>% filter(is.na(value)==FALSE)%>%
          select(c("variable", "value"))%>% group_by(variable) %>% mutate (n=n())%>%
          filter(value==0) %>% mutate (zero = n()) %>% distinct(.keep_all = TRUE) %>% select(c("variable", "zero"))

        sample_summary <- left_join(sample_summary, sample_zero, by = "variable")
        sample_summary[which(is.na(sample_summary$zero)), "zero"] <- 0


        sample_summary$percent <- paste0(sprintf("%.1f", round(sample_summary$zero/sample_summary$n*100, 1)) ,"%")

        out <- bar_plot (Local_mean, probs = NULL, plot.flag = FALSE,title)
        ymin <- (- diff(range(out$coordinates$limits$y,na.rm = TRUE)) * 0.02)

        out <- out +
         annotate("text",x= sample_summary$variable, y =  ymin,
                   hjust = 1, label = sample_summary$percent , size = 3.5)

        print (out)

      } else if (isTRUE(type == "bees")){
        #  summary plot
         out <- summary_plot (local_total,title)
        print (out)

      }
      }


      else if (isFALSE (is.null(num_post))){

      # num_post th posterior sample = #obs by #variable
      obs <- foreach(i = 1: length(object $ phis), .combine = 'cbind' ) %do% {
        object$phis[[i]] [,num_post]
      }
      colnames(obs) <- names(object$phis)

      for (i in length_cate){
        temp_i <- which (object$newdata [,i] !=1)
        obs[temp_i,i] <- NA
      }

      local_obs <- long_data (obs, normalize = TRUE, absolute = TRUE)

      if (isTRUE(type == "bees") | is.null (type)){
        # Local SHAP summary plot - i th posterior
        out <- summary_plot (local_obs ,title)
         annotate_figure(out, top = text_grob(paste0("Sample number = ", num_post),
                                                                     hjust = 1, x = 0.95,vjust = 1.05, size = 10 ))
      } else if (isTRUE(type == "bar")) {

        out <- bar_plot (abs(obs), probs =NULL, plot.flag = FALSE,title )

        sample_summary <- local_obs$long %>% filter (is.na (value)==FALSE)%>%
          select(c("variable", "value"))%>% group_by(variable) %>% mutate (n=n()) %>%
          select (c("variable","n")) %>% distinct(.keep_all = TRUE)

        sample_zero <-  local_obs$long  %>% filter (is.na (value)==FALSE)%>%
          select(c("variable", "value"))%>% group_by(variable) %>% mutate (n=n())%>%
          filter(value==0) %>% mutate (zero =n()) %>% distinct(.keep_all = TRUE) %>% select(c("variable", "zero"))

        sample_summary <- left_join(sample_summary, sample_zero, by = "variable" )
        sample_summary [which( is.na(sample_summary$zero)), "zero"] <- 0

        sample_summary$ percent <- paste0(sprintf("%.1f", round( sample_summary$zero/sample_summary$n*100, 1)) ,"%")

         ymin <- (- diff(range(out$coordinates$limits$y,na.rm = TRUE)) * 0.02)


         annotate_figure(out + annotate("text",x= sample_summary$variable, y =  ymin,
                                            hjust = 1, label = sample_summary$percent , size = 3.5),
                                 top =  text_grob(paste0("Sample number = ", num_post),
                                                               hjust = 1, x = 0.95,vjust = 1.05, size = 10 ))

      }
    }



  } else if(isTRUE(average=="both")) {

    for( i in length_cate) {
      temp_i <- which(object$newdata[,i] !=1)
      object$phis[[i]][temp_i,] <- NA
    }

    # Average based on observation= #post by #variable
    obs_mean_shap <- as.data.frame(foreach(i = 1 : length(object$phis), .combine = 'cbind' ) %do% {
      apply(object$phis[[i]], 2, function(x) {mean(abs(x), na.rm= T)})
    })
    colnames(obs_mean_shap) <- names(object$phis)


    mean_obs <- colMeans(obs_mean_shap) [order(colMeans(obs_mean_shap), decreasing = TRUE) ]
    mean_obs <- as.data.frame(mean_obs)
    names (mean_obs) <- "mean"
    mean_obs$Average <- "Observation"
    mean_obs$variable <- obs_variable <- rownames (mean_obs)

    obs_mean_shap$Average <- "Observation"
    obs_mean_shap$ID <- rownames(obs_mean_shap)



    # Average based on posterior sample = #obs by #variable

    post_mean_shap <- as.data.frame(foreach(i = 1:length(object$phis), .combine = 'cbind' ) %do% {
      apply(object$phis[[i]], 1, function(x) {abs(mean(x))})
    })
    colnames(post_mean_shap) <- names(object$phis)

    for (i in length_cate){
      temp_i <- which (object$newdata[,i] !=1)
      post_mean_shap[temp_i,i] <- NA
    }

    mean_post <- colMeans(post_mean_shap, na.rm = TRUE) [order(colMeans(post_mean_shap,na.rm = TRUE), decreasing = TRUE) ]
    mean_post <- as.data.frame(mean_post)
    names (mean_post) <- "mean"
    mean_post$Average <- "Samples"
    mean_post$variable <- rownames (mean_post)

    post_mean_shap$Average <- "Samples"
    post_mean_shap$ID <- rownames(post_mean_shap)


    total_mean_shap <- rbind (obs_mean_shap, post_mean_shap )

    total_long <- melt(total_mean_shap, id =c('ID',"Average"))
    total_long$Average_re <- fct_rev(total_long$Average)

    mean_data <- rbind (mean_obs, mean_post)
    mean_data$Average_re <- fct_rev( mean_data$Average)

    data_list <- list(total_long = total_long, mean_data = mean_data)


    if ( is.null(type) | isTRUE(type == "bees")) {

      ymax <- max (data_list$total_long$value, na.rm = TRUE) * (1+0.001)
      ymin <- (- diff(range(data_list$total_long$value, na.rm = TRUE))*0.05)

      left_p <-  data_list$total_long %>% filter (is.na(value)==FALSE & Average_re=="Observation")%>%
        ggplot( aes(x= variable, y=value, fill= Average_re )) +
        geom_boxplot() +coord_flip() + theme_bw(base_size = 11) +
        labs(fill = "", x="",y="Mean(|SHAP|)") +
        scale_x_discrete(limits = rev(obs_variable),
                         labels = rev(obs_variable))+
        scale_fill_manual(values=c("#F8766D"))+
        theme(legend.position = c(0.8, 0.2), legend.background=element_blank()) + ylim(ymin, ymax )

      sample_summary <- data_list$total_long %>% filter (is.na (value)==FALSE & Average_re=="Samples")%>%
        select(c("variable", "value")) %>% group_by(variable) %>% mutate (n=n()) %>%
        select (c("variable","n")) %>% distinct(.keep_all = TRUE)

      sample_zero <- data_list$total_long %>% filter (is.na (value)== FALSE & Average_re=="Samples")%>%
        select(c("variable", "value"))%>% group_by(variable) %>% mutate (n=n())%>%
        filter(value==0) %>% mutate (zero=n()) %>% distinct(.keep_all = T) %>% select(c("variable", "zero"))

      sample_summary <- left_join(sample_summary, sample_zero, by = "variable" )
      sample_summary [which( is.na(sample_summary$zero)), "zero"] <- 0

      sample_summary$percent <- paste0(sprintf("%.1f", round(sample_summary$zero/sample_summary$n*100, 1)),"%")

      right_p <-  data_list$total_long %>% filter (is.na(value)==FALSE & Average_re=="Samples")%>%
        ggplot( aes(x = variable, y = value, fill = Average_re)) +
        geom_boxplot() + coord_flip() + theme_bw(base_size = 11) +
        labs(fill = "", x="",y="Mean(|SHAP|)") +
        scale_x_discrete(limits = rev(obs_variable),
                         labels = rev(obs_variable))+
        scale_fill_manual(values=c( "#00BFC4"))+
        theme(legend.position = c(0.8, 0.2), legend.background=element_blank()) + ylim(ymin, ymax)

      right_p <- right_p + annotate("text",x= sample_summary$variable,
                                  y = - diff(range(data_list$total_long$value,na.rm = TRUE))*0.02 ,
                                  hjust = 1, label = sample_summary$percent, size = 2.5)


      grid.arrange(left_p, right_p, ncol= 1, top= textGrob(title, x = 0.2, hjust = 0)  )

      if (isTRUE(type =="bees")) {
        message("In Average = 'both',\n a baxplot is also provided by entering type='bees'.")
      }

    } else if (isTRUE(type == "bar")){
      out <- ggplot( data_list$mean_data, aes(x= variable, y= mean, fill = Average_re )) +
        geom_bar( stat = "identity" , position="dodge") +coord_flip() + theme_bw(base_size = 11) +
        scale_fill_manual(values=c( "#00BFC4","#F8766D"))+
        labs(fill = "Criteria for average ", x="",y="Mean(|SHAP|)") +
        scale_x_discrete(limits = rev(obs_variable), labels = rev(obs_variable)) +
        ylim(c(0,max(data_list$mean_data$mean)))+
        geom_text(aes(label = sprintf("%.3f",round(mean,3))),
                  hjust ="inward", size= 3.5, position = position_dodge(width=0.9))+
        theme(legend.position = "bottom")

        if(!is.null(title)) {
         out <- out + ggtitle(title)
       }
       print(out)

    }

  }
}
}

Try the bartXViz package in your browser

Any scripts or data that you put into this service are public.

bartXViz documentation built on Aug. 8, 2025, 6:23 p.m.