# Questions for r

7711

### How to add a 2nd y-axis for a density plot superimposed on a histogram in R?

I have a histogram shown below, and I have added 2 density plots on top of that. It corresponds to the 2 classes that make up the data.5009

### How to write coercion methods

I'm having a bunch of custom-made Reference Classes and would like to write coercion methods for some of them. It'd be nice if a function call would look like this:5564

### How to get started with Big Data Analysis

I've been a long time user of R and have recently started working with Python. Using conventional RDBMS systems for data warehousing, and R/Python for number-crunching, I feel the need now to get my8769

### How to manually set coefficients for variables in linear model?

In R, how can I set weights for particular variables and not observations in lm() function?4883

### R - How to sum objects in a column between an interval defined by conditions on another column

This comes as an application to this question:Sum object in a column between an interval defined by another column4475

### Create a table for N, Min/Max, SD, Mean, and Median in R

I'm very new to R, so please bear with me on this basic question.5779

### How can an line be overlaid on a a bar plot using ggplot2?

I'm looking for a way to plot a bar chart containing two different series, hide the bars for one of the series and instead have a line (smooth if possible) go through the top of where bars for the ...7708

### R Cannot allocate memory though memory seems to be available

After running several models I need to run a system() command on my R script to shutdown my EC2 instance, but when I get to that point I get:4862

### ggplot2 plot fill page in landscape (pdf)

I'm trying to render a plot to a PDF using the following approach:9631

### Extracting Certain Data from a Data Set Using R

I have difficulties in extracting certain line from a data.7009

### Discarding non-decimal values in R

I've got the a data frame called "odds" in R containing a couple of odds I kept track of in several formats:5674

### how to specify the labels of vertices in R

I have an matrix as below:2720

### Sample with constraint, vectorized

What is the most efficient way to sample a data frame under a certain constraint?5466

### Using `geom_line()` with X axis being factors

Suppose I have a dataframe:2237

### SQL querying dataframes inside list

Given the dataframes2021

### How do I set values to a Tk combobox in R

I sometimes have a dropdown box with only one item to choose from, but this item might be a string with spaces. How can I do this in R? Here is the problem:779

### How can I color the ocean blue in a map of the US?

I would like to draw a map of the US over an image, but then fill in the oceans.1108

### Figure numbers generated by Sweave/R and why only (PDF)LaTeX

I am continuing my earlier post here:3093

### R: format the output of `warning()` for a list of options over more than one line

I'm writing error handling steps for an R function that fails to find the right match to a query, so presents users with a list of options. I have the output of potential matches in a list, and I'...6964

### Beginner's questions (figures, bibliography) with Sweave/R/LaTeX---my first document

I am just starting with Sweave and with R. Here I am using R to output some data and I am also trying to include a plot. The code does not sweave. I have one Sweave example from the web that compiles6334

### Plot only diagonal entries with data.frame of many time-series in R

I have several time series, which when I plot using,1728

### R as a general purpose programming language

I liked Python before because Python has rich built-in types like sets, dicts, lists, tuples. These structures help write short scripts to process data.9466

### What's the fastest way to merge/join data.frames in R?

For example (not sure if most representative example though):8276

### Why I obtain wrong answer when using “==”

Something I do not understand is happening on two of my computers. I wonder why this is happening:6490

### R incrementing by decimal value does not return expected value

I am writing a function in R that requires me to increment a counter by 0.05. When I condition on the value of the counter I am getting told that the value is not what it appears.437

### How to add layers with new data to a ggplot with a POSIX axis?

I'm used to this if I want to add a point to a ggplot, it works just fine:5682

### using stringr to split vectors, unexpected result length

Something simple I'm messing up in using stringr to manipulate character vectors. I have a data frame of the following sort1890

### Save graph from R as editable graphic in Excel

I am writing a GUI in R, and one of the functions I must implement is a button to save graphical output to an Excel sheet, ideally the graphic should be editable in Excel. I am trying to do this the6561

### big.matrix as data.frame in R

I've recently started using R for data analysis. Now I've got a problem in ranking a big query dataset (~1 GB in ASCII mode, over my laptop's 4GB RAM in binary mode). Using bigmemory::big.matrix fo...9625

### R 2.14 byte compilation - how much performance increase

I saw that the latest R version supports byte compilation. What is the performance gain I can expect? And are specific tasks more positively impacted that others?6368

### R: Plotting 4x4 plot with for -loop and png, why getting 1x1 plot instead of 4x4?

I can get the 4x4 plot working when I try it on command line but not with for -loop and png element in the code below. I am frustrated what the heck the problem is, I have tried to understand this ...4727

### Change dots of a ggplot to text labels

Recently i asked a question about getting multiple graphs within 1 picture. I got some pretty good answers but 1 question still remains.1919

### Group rows by attributes

I have a data frame containing data about student lateness to various classes. Each row contains data about a late student and his class: date and time of the class, name of the class, class size, ...793

### My R has memory leaks?

I'm using R 2.15.3 on Ubuntu 12.04 (precise) 64-bit.6062

### Subset data using non-sequential row numbers

I have a data frame with 30 rows and 100 columns (X).6227

### R - How to do Python's Try Except

I'm starting to work with R. Although I'm more used to python.9238

### Predicted Probabilities with Predict.Plot

I'm running the following logistic regression model in R and one of the important predictors is our_bid, which is a numeric and continuous variable that ranges from 0.30 to 0.80. When I attempt to...4171

### R lapply statement with index

Is there a way I can make an lapply statement also show the index? More specifically, consider the following example:642

### Regular expression in R

I am having some troubles with the regular expression in R. I use str_extract from the library stringr and my problem is :7915

### creating factors in R with differing number of replicates

The following command7441

### Solving quadratic programming using R

I would like to solve the following quadratic programming equation using ipop function from kernlab :5202

### Cross-difference between arrays without using for loop

Using the following code:3041

### Apply function on each cell in a column and add the result to a new column

I have a data.table as shown below. What I want is to apply a function to each of the elements in column C. The function will take in a vector(since Col C contains vector elements) and return another7179

### R and ggplot- Changing x axis to Date removes position dodge

I've been using ggplot to create plots, and I always like to offset my data points horizontally so the error bars don't overlap. I've found that when I used Date data for my x axis, I loose the abi...6406

### Efficient way to define a class with multiple, optionally-empty slots in S4 of R?

I am building a package to handle data that arrives with up to 4 different types. Each of these types is a legitimate class in the form of a matrix, data.frame or tree. Depending on the way the dat...1710

### How do I call a namespaced function without evaluating the parameters you are giving it?

In R, the idiomatic way to call another function without evaluating the parameters you give it is apparently as follows:1009

### Trouble reading a data set into R

I am new to R and I am trying to read in a data set. The data set is here:2500

7368

### Plotting multiple columns with ggplot2

I need to plot the following dataset in the same graph.2886

### How to install 2 different R versions on Debian?

On our server, R 2.12.1 is installed following the instructions on http://cran.r-project.org/bin/linux/debian/ , using apt-get install etc etc.7807