Question

当尝试在条件中绘制多个d3heatmaps时，生成的HTML仅绘制最终的热图。下面是RMD重现错误的代码。

---
title: "test"
output: html_document
---

This is an R Markdown document. 

```{r}
require(d3heatmap)
myVar = TRUE
if (myVar == TRUE) {
  d3heatmap(mtcars, col = "Spectral")
  d3heatmap(mtcars, col = "Blues")
}
```

如果热图超出条件，则多个将出现在编织的HTML文件中。还有其他人遇到过这个吗？

sessionInfo()
R version 3.2.3 (2015-12-10)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: OS X 10.11.3 (El Capitan)

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] d3heatmap_0.6.1.1

loaded via a namespace (and not attached):
 [1] htmlwidgets_0.6 magrittr_1.5    htmltools_0.3   tools_3.2.3     base64enc_0.1-3
 [6] yaml_2.1.13     stringi_1.0-1   rmarkdown_0.9.5 knitr_1.12.3    stringr_1.0.0  
[11] digest_0.6.9    evaluate_0.8.3  png_0.1-7

Answer 1

this answer by Yihui中解释了基本问题：HTML小部件“仅在从顶级 R表达式生成时才起作用”。这解释了为什么将图包装在if语句中不起作用。不过第二个图是可见的，因为if返回最后一个表达式的值，从而将最后一个图“提升”到顶层。

作为解决方案，可以按照建议here通过htmltools::tagList将列表收集到列表中并打印：

```{r}
require(d3heatmap)
myVar = TRUE
res <- list()
if (myVar == TRUE) {
  res[[1]] <- d3heatmap(mtcars, col = "Spectral")
  res[[2]] <- d3heatmap(mtcars, col = "Blues")
}

htmltools::tagList(res)
```

发布使用knitr绘制多个d3heatmaps的条件

1 个答案: