在R markdown中嵌入使用函数生成的googleVis图表

Question

I have a function that creates the same type of googleVis plot for different data frames. These plots are to be embedded in a Markdown file. Embedding a single plot with the result='asis' option fails to achieve my objective when the chart object is created by my function. Following is a dummy code for the same:

Embedded googleVis plots
=====================

Some text here

```{r}
library(googleVis)
op <- options(gvis.plot.tag="chart")
```

And now the plot

```{r result='asis', tidy=TRUE}
mark_func <- function(data) {
    data$Mean=mean(data$Popularity)
    CC <- gvisComboChart(data, xvar='City',
          yvar=c('Mean', 'Popularity'),
          options=list(seriesType='bars',
                       width=450, height=300,
                       title='City Popularity',
                       series='{0: {type:"line"}}'))
    return(CC)
}
```

```{r result='asis', tidy=TRUE}
plt <- mark_func(CityPopularity)
plot(plt)`
```  

I am converting this Markdown file to a HTML using knit2html from the knitr package and viewing this HTML in Firefox. Instead of seeing a plot, I see a long HTML code.

What is it that I am missing? Thanks for your help.

Answer 1

It is just typos. You are forgetting to escape your quotemarks at the end and the code chunk option should be results , not result .

Working code:

%\VignetteEngine{knitr::knitr}

```{r}
library(googleVis)
op <- options(gvis.plot.tag="chart")
```

```{r results='asis', tidy=TRUE}
mark_func <- function(d) {
    d$Mean=mean(d$Popularity)
    CC <- gvisComboChart(d, xvar='City',
          yvar=c('Mean', 'Popularity'),
          options=list(seriesType='bars',
                       width=450, height=300,
                       title='City Popularity',
                       series='{0: {type:\"line\"}}'))
    return(CC)
}
```

```{r results='asis', tidy=TRUE}
plt <- mark_func(CityPopularity)
plot(plt)
```