Ggplot2: Difference between revisions

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apt-get install ghostscript -y
apt-get install ghostscript -y
</pre>
</pre>
===Legends===
[https://ggplot2.tidyverse.org/articles/articles/faq-customising.html?q=legend#legends Customizing FAQ]<br>
[https://ggplot2.tidyverse.org/reference/guide_legend.html guide_legend]
<syntaxhighlight lang="R">
# Move legend to the bottom
plot <- plot +  theme(legend.position = "bottom")
# Set color legend to have two rows
plot <- plot +  guides(color=guide_legend(nrow=2, byrow=TRUE))
</syntaxhighlight>

Latest revision as of 20:05, 12 January 2022

ggplot2 is a plotting tool for R

Usage

Resources

Bar Chart

Example bar graph:

data(mtcars)
library(ggplot2)
ggplot(mtcars, aes(x=cyl, y=wt)) + 
  geom_bar(stat="identity", fill="steelblue") +
  xlab("Cylinders") + 
  ylab("Weight (1000 lbs)") + 
  ggtitle("Car Weight vs Cylinders") +
  theme_gray() + 
  theme(plot.title = element_text(hjust = 0.5))

Line Graph

Pie Chart

Saving Images

ggsave documentation

# Save as PDF
ggsave("barchart_example.pdf", plot=plt, width=6, height=4, device="pdf")
embedFonts(path.expand("barchart_example.pdf"))

# Save as PNG
ggsave("barchart_example.png", plot=plt, width=6, height=4, dpi=300)

For embedding in a latex file, I recommend exporting as PDF. This allows exporting as a vector format with text.
If you must export as a raster image (jpeg, png), set the dpi flag to get a high-resolution image.

Note that embed fonts requires ghostscript:

apt-get install ghostscript -y

Legends

Customizing FAQ
guide_legend

# Move legend to the bottom
plot <- plot +  theme(legend.position = "bottom")

# Set color legend to have two rows
plot <- plot +  guides(color=guide_legend(nrow=2, byrow=TRUE))