Графики R Markdown ggvis не отображаются

У меня возникли проблемы с отображением графиков в R Markdown.
Выполнение приведенного ниже кода в скрипте R работает нормально и создает диаграммы. Запуск того же кода в документе R Markdown не работает.

Спасибо @aosmith за этот пост. для группировки диаграмм.

---
title: "TestingIssue"
author: "John"
date: "August 18, 2015"
output: html_document
---

```{r, results='asis'}
# Load visualization & manipulation libraries
library(ggvis)
library(dplyr)
library(knitr) # added this per aosmith suggestion

# Build DF
dailyCaloriesDF <- structure(list(Name = c("Amy", "Amy", "Amy", "Amy", "Amy", "Amy", 
                        "Amy", "Amy", "Amy", "Sue", "Sue", "Sue", "Sue", "Sue", "Sue", 
                        "Sue", "Sue", "Sue", "Jim", "Jim", "Jim", "Jim", "Jim", "Jim", 
                        "Jim", "Jim", "Jim"), 
               Date = c("1/1/2015", "1/2/2015", "1/3/2015", 
                        "1/4/2015", "1/5/2015", "1/6/2015", "1/7/2015", "1/8/2015", "1/9/2015", 
                        "1/1/2015", "1/2/2015", "1/3/2015", "1/4/2015", "1/5/2015", "1/6/2015", 
                        "1/7/2015", "1/8/2015", "1/9/2015", "1/1/2015", "1/2/2015", "1/3/2015", 
                        "1/4/2015", "1/5/2015", "1/6/2015", "1/7/2015", "1/8/2015", "1/9/2015"), 
               Calories = c(1700L, 1650L, 1600L, 1550L, 1500L, 1450L, 1400L, 
                            1350L, 1300L, 2000L, 1950L, 1900L, 1850L, 1800L, 1750L, 1700L, 
                            1650L, 1600L, 1800L, 1750L, 1700L, 1650L, 1600L, 1550L, 1500L, 
                            1450L, 1400L)), 
          .Names = c("Name", "Date", "Calories"), 
          class = c("tbl_df", "tbl", "data.frame"), 
          row.names = c(NA, -27L))

# Build function
makeCharts = function(dat) {
  dat %>% ggvis(~Date, ~Calories)
}

# Execute for each group by name
allplots2 = dailyCaloriesDF %>%
  group_by(Name) %>%
  do(plots = makeCharts(.))

# Print plots - This won't work in markdown, but will work in script
allplots2$plots

# New code, per aosmith suggestion
data(mtcars)
plots <- lapply(1:5, function(x){
  ggvis(mtcars, ~cyl, ~mpg) %>% layer_points() %>% knit_print
})
html <- paste0(lapply(plots, unclass), collapse = "\n")
asis_output(html, ggvis_dependencies(absolute = TRUE, in_shiny = FALSE))

```

Когда я запускаю этот код в документе уценки, я просто получаю вывод консоли в сгенерированном документе.

[[1]]

[[2]]

[[3]]

...

Новый код дает это сообщение об ошибке:

Quitting from lines 9-53 (testOutput.Rmd) 
Error in structure(x, class = "knit_asis", knit_meta = meta, knit_cacheable = cacheable) : 
  could not find function "ggvis_dependencies"
Calls: <Anonymous> ... withVisible -> eval -> eval -> asis_output -> structure