R question. Using lappy on a data.frame and creating new variables w/ output.

Posted by Michael on Stack Overflow See other posts from Stack Overflow or by Michael
Published on 2010-05-09T16:36:25Z Indexed on 2010/05/09 16:38 UTC
Read the original article Hit count: 186

Filed under:

statistics

|

data.frame

|

lapply

|

r

Hello,

I have 13 quantitative variables in a data.frame (called 'UNCA').

The variables are named q01_a, q01_b, ...q01_m.

I want to create 13 new variables that have the same values but are coded as a factor.

I would like to name these 13 new variables q01_a.F, q01_b.F, ...q01_m.F.

Any help would be greatly appreciated!

© Stack Overflow or respective owner

Related posts about statistics

SQL SERVER – When are Statistics Updated – What triggers Statistics to Update

as seen on SQL Authority - Search for 'SQL Authority'
If you are an SQL Server Consultant/Trainer involved with Performance Tuning and Query Optimization, I am sure you have faced the following questions many times. When is statistics updated? What is the interval of Statistics update? What is the algorithm behind update statistics? These are the puzzling… >>> More
SQL SERVER When are Statistics Updated What triggers Statistics to Update

as seen on Dot net Slackers - Search for 'Dot net Slackers'
If you are an SQL Server Consultant/Trainer involved with Performance Tuning and Query Optimization, I am sure you have faced the following questions many times.When is statistics updated? What is the interval of Statistics update? What is the algorithm behind update statistics? These are the puzzling… >>> More
New Whitepaper: Best Practices for Gathering EBS Database Statistics

as seen on Oracle Blogs - Search for 'Oracle Blogs'
Most Oracle Applications DBAs and E-Business Suite users understand the importance of accurate database statistics. Missing, stale or skewed statistics can adversely affect performance. Oracle E-Business Suite statistics should only be gathered using FND_STATS or the Gather Statistics… >>> More
Incremental Statistics Maintenance – what statistics will be gathered after DML occurs on the table?

as seen on Oracle Blogs - Search for 'Oracle Blogs'
Incremental statistics maintenance was introduced in Oracle Database 11g to improve the performance of gathering statistics on large partitioned table. When incremental statistics maintenance is enabled for a partitioned table, oracle accurately generated global level statistics by aggregating… >>> More
Lies, damned lies, and statistics Part 2

as seen on Oracle Blogs - Search for 'Oracle Blogs'
There was huge interest in our OOW session last year on Managing Optimizer Statistics. It seems statistics and the maintenance of them continues to baffle people. In order to help dispel the mysteries surround statistics management we have created a two part white paper series on Optimizer statistics… >>> More

Related posts about data.frame

Subsetting a data frame in a function using another data frame as parameter

as seen on Stack Overflow - Search for 'Stack Overflow'
I would like to submit a data frame to a function and use it to subset another data frame. This is the basic data frame: foo <- data.frame(var1= c('1', '1', '1', '2', '2', '3'), var2=c('A', 'A', 'B', 'B', 'C', 'C')) I use the following function to find out the frequencies of var2 for specified… >>> More
Substitute values (for specific dates) from a second data frame to the first data frame

as seen on Stack Overflow - Search for 'Stack Overflow'
I have two time series data frames: The first one: head(df1) : GMT MSCI ACWI DJGlbl Russell 1000 Russell Dev S&P GSCI Industrial S&P GSCI Precious 1999-03-01 -0.7000000 0.2000000 -0.1000000 -1.5000000 -1.0000000 -0.4000000 1999-03-02 -0.5035247 0.0998004… >>> More
Convert ddply {plyr} to Oracle R Enterprise, or use with Embedded R Execution

as seen on Oracle Blogs - Search for 'Oracle Blogs'
The plyr package contains a set of tools for partitioning a problem into smaller sub-problems that can be more easily processed. One function within {plyr} is ddply, which allows you to specify subsets of a data.frame and then apply a function to each subset. The result is gathered into a single data… >>> More
Subset a data.frame by list and apply function on each part, by rows

as seen on Stack Overflow - Search for 'Stack Overflow'
This may seem as a typical plyr problem, but I have something different in mind. Here's the function that I want to optimize (skip the for loop). # dummy data set.seed(1985) lst <- list(a=1:10, b=11:15, c=16:20) m <- matrix(round(runif(200, 1, 7)), 10) m <- as.data.frame(m) dfsub <-… >>> More
Appending column to a data frame - R

as seen on Stack Overflow - Search for 'Stack Overflow'
Is it possible to append a column to data frame in the following scenario? dfWithData <- data.frame(start=c(1,2,3), end=c(11,22,33)) dfBlank <- data.frame() ..how to append column start from dfWithData to dfBlank? It looks like the data should be added when data frame is being initialized… >>> More