在RShiny报告的Rmd文件中无法并排显示两个ggplotly图表的技术求助

Hey there, I totally get why this is frustrating—you tried all the usual knitr figure parameters to get those two ggplotly charts side-by-side, but they just keep stacking vertically. The root issue here is that ggplotly generates interactive HTML widgets, not static ggplot images—so knitr's fig.show='hold', out.width, etc., don't affect them at all. These widgets are block-level elements by default, meaning they take up the full width of their container and stack on top of each other.

Let's walk through a couple of reliable fixes:

Solution 1: Use htmltools with Flexbox (Recommended) #

We can use the htmltools package to create a flex container that forces the two charts to sit next to each other. Here's how to adjust your code:

{r echo=FALSE}
library(htmltools)

# First, create your two ggplotly objects separately (cleaner code!)
plot1 <- ggplotly(
  qplot(params$sdr_v$Voltage_sensor, params$sdr_v$sdr, 
        xlab= "Voltage sensors", ylab = "SDR(mV/day)") +
    geom_point(aes(x = params$sdr_v$Voltage_sensor, y= params$sdr_v$sdr)) +
    theme(axis.text.x = element_text(angle = 45, vjust = 1.0, hjust = 1.0)) +
    theme(legend.position = "none", axis.text.x = element_blank())
)

plot2 <- ggplotly(
  qplot(params$sdr_s$Voltage_sensor, params$sdr_s$sdr_soc, 
        xlab= "Voltage sensors", ylab = "SDR (%SOC/day)") +
    geom_point(aes(x = params$sdr_s$Voltage_sensor, y= params$sdr_s$sdr_soc, 
                   colour = params$sdr_s$sdr_soc > 0.016)) +
    scale_colour_manual(values = c("black", "red")) +
    theme(axis.text.x = element_text(angle = 45, vjust = 1.0, hjust = 1.0)) +
    theme(legend.position = "none", axis.text.x = element_blank())
)

# Create a flex container to arrange them side-by-side
div(
  style = "display: flex; gap: 1.5rem; justify-content: center;",
  div(plot1, style = "width: 48%;"),
  div(plot2, style = "width: 48%;")
)

A quick breakdown of the CSS here:

• display: flex: Turns the outer div into a flex container, which lets its children (the charts) arrange horizontally
• gap: 1.5rem: Adds a small space between the two charts so they don't look cramped
• width: 48%: Makes each chart take up almost half the container width (leaving a little room for the gap)
• justify-content: center: Centers the pair of charts in the container

Solution 2: Use bslib's Grid Layout (Great for Bootstrap Themes) #

If your R Markdown document uses a Bootstrap theme (which is the default for html_document), the bslib package makes this even simpler with its layout_columns() function:

{r echo=FALSE}
library(bslib)

# Reuse plot1 and plot2 from Solution 1 above

layout_columns(
  col_widths = c(6, 6), # Split Bootstrap's 12-column grid evenly between the two charts
  plot1, plot2
)

This method avoids writing custom CSS entirely and works seamlessly with Bootstrap's responsive design—your charts will even stack on smaller screens automatically.

Why Your Original Code Didn't Work #

Just to clarify: Knitr's fig.* parameters (like fig.show='hold', out.width) are designed for static image outputs (PNGs, PDFs, etc.). Since ggplotly produces htmlwidgets (essentially chunks of HTML/JS), those knitr settings don't have any control over how they're laid out in the final HTML report. You need to use HTML/CSS-based layout tools instead.

内容的提问来源于stack exchange，提问作者cagla