Top and Bottom plots seem to have less spacing when using `subplot` in `plotly`

Inizia eseguendo il reprex R fornito con subplot e 45 istogrammi per riprodurre il problema di spaziatura tra la riga superiore e quella inferiore. Traccia il comportamento del layout di subplot e verifica che gli istogrammi risultanti abbiano margini uguali con etichette visibili; il problema è risolto quando i grafici superiori e inferiori sono distanziati in modo coerente.

Description:

When attempting to display multiple histograms using subplot from the plotly package, the plots in the top row and bottom row appear with less spacing, making them difficult to analyze. This issue is primarily reproducible when there are large number of visualizations to plot together.

Here is a minimal reprex for the same:

# Load necessary libraries
library(ggplot2)
library(plotly)

# set seed for reproducibility
set.seed(123)

# simulate a dataset
simulateDataset <- function(numRows = 100, numCols = 40) {
  data <- data.frame(matrix(nrow = numRows, ncol = numCols))
  
  for (i in 1:numCols) {
    if (i %% 2 == 0) {
      data[[i]] <- rnorm(numRows, mean = 50, sd = 10)  # Normal distribution
    } else {
      data[[i]] <- rexp(numRows, rate = 0.1)           # Exponential distribution
    }
  }
  
  names(data) <- paste0("Var", 1:numCols)
  return(data)
}

# simulate the data
df <- simulateDataset(numRows = 100, numCols = 45)

# create histograms and convert to plotly
plotList <- lapply(names(df), function(colName) {
  if (is.numeric(df[[colName]])) {
    p <- ggplot(df, aes(x = .data[[colName]])) + 
      geom_histogram(binwidth = 0.5, fill = 'grey', color = 'black')
    
    ggplotly(p)
  }
})

# define number of rows based on number of plots in each row
numberOfRows <- ceiling(length(plotList) / 3)

# display all plots together using subplot
subplot(plotList, nrows = numberOfRows, margin = 0.05, titleX = TRUE, titleY = TRUE)

Expected Behavior:
Each histogram should have equal margins, with appropriate spacing and labels visible.

Screenshots