Memory profiling in R - tools for summarizing

profvis looks like the the solution to this question.

It generates an interactive .html file (using htmlwidgets) showing the profiling of your code.

The introduction vignette is a good guide on its capability.

Taking directly from the introduction, you would use it like this:

devtools::install_github("rstudio/profvis")
library(profvis)

# Generate data
times <- 4e5
cols <- 150
data <- as.data.frame(x = matrix(rnorm(times * cols, mean = 5), ncol = cols))
data <- cbind(id = paste0("g", seq_len(times)), data)
profvis({
    data1 <- data   # Store in another variable for this run

    # Get column means
    means <- apply(data1[, names(data1) != "id"], 2, mean)

    # Subtract mean from each column
    for (i in seq_along(means)) {
        data1[, names(data1) != "id"][, i] <- data1[, names(data1) != "id"][, i] - means[i]
    }
}, height = "400px")

Which gives

Check out profr -- it seems like exactly what you're looking for.