r Archives - Page 14 of 17

How to change legend title in ggplot

I have the following plot like below. It was created with this command: library(ggplot2) df <- data.frame(cond = factor(rep(c("A", "B"), each = 200)), ...

May 6, 2022
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Why is `[` better than `subset`?

When I need to filter a data.frame, i.e., extract rows that meet certain conditions, I prefer to use the subset function: subset(airquality, Month ...

May 6, 2022
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Extracting specific columns from a data frame

I have an R data frame with 6 columns, and I want to create a new dataframe that only has three of the ...

May 6, 2022
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How to add leading zeros?

I have a set of data which looks something like this: anim <- c(25499,25500,25501,25502,25503,25504) sex <- c(1,2,2,1,2,1) wt <- c(0.8,1.2,1.0,2.0,1.8,1.4) data <- data.frame(anim,sex,wt) ...

May 6, 2022
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How do I install an R package from source?

A friend sent me along this great tutorial on webscraping The New York Times with R. I would really love to try it. ...

May 6, 2022
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How can two strings be concatenated?

How can I concatenate (merge, combine) two values? For example I have: tmp = cbind("GAD", "AB") tmp # [,1] [,2] #...

May 6, 2022
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Cluster analysis in R: determine the optimal number of clusters

Being a newbie in R, I’m not very sure how to choose the best number of clusters to do a k-means analysis. After ...

May 5, 2022
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How to sum a variable by group

I have a data frame with two columns. First column contains categories such as “First”, “Second”, “Third”, and the second column has numbers ...

May 5, 2022
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I want to write trycatch code to deal with error in downloading from the web. url <- c( "http://stat.ethz.ch/R-manual/R-devel/library/base/html/connections.html", "http://en.wikipedia.org/wiki/Xz") y <- mapply(readLines, ...

May 5, 2022
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