SyntaxFix

[r] Select subset of columns in data.table R

This seems an improvement:

> cols<-!(colnames(dt) %in% c("V1","V2","V3","V5"))
> new_dt<-subset(dt,,cols)
> cor(new_dt)
            V4          V6          V7          V8         V9         V10
V4   1.0000000  0.14141578 -0.44466832  0.23697216 -0.1020074  0.48171747
V6   0.1414158  1.00000000 -0.21356218 -0.08510977 -0.1884202 -0.22242274
V7  -0.4446683 -0.21356218  1.00000000 -0.02050846  0.3209454 -0.15021528
V8   0.2369722 -0.08510977 -0.02050846  1.00000000  0.4627034 -0.07020571
V9  -0.1020074 -0.18842023  0.32094540  0.46270335  1.0000000 -0.19224973
V10  0.4817175 -0.22242274 -0.15021528 -0.07020571 -0.1922497  1.00000000

This one is not quite as easy to grasp but might have use for situations there there were a need to specify columns by a numeric vector:

subset(dt, , !grepl(paste0("V", c(1:3,5),collapse="|"),colnames(dt) ))

Examples related to r

• How to get AIC from Conway–Maxwell-Poisson regression via COM-poisson package in R? • R : how to simply repeat a command? • session not created: This version of ChromeDriver only supports Chrome version 74 error with ChromeDriver Chrome using Selenium • How to show code but hide output in RMarkdown? • remove kernel on jupyter notebook • Function to calculate R2 (R-squared) in R • Center Plot title in ggplot2 • R ggplot2: stat_count() must not be used with a y aesthetic error in Bar graph • R multiple conditions in if statement • What does "The following object is masked from 'package:xxx'" mean?

Examples related to data.table

• Error: package or namespace load failed for ggplot2 and for data.table • Select subset of columns in data.table R • How to get week numbers from dates? • data.table vs dplyr: can one do something well the other can't or does poorly? • How to replace NA values in a table for selected columns • Select multiple columns in data.table by their numeric indices • Sort rows in data.table in decreasing order on string key `order(-x,v)` gives error on data.table 1.9.4 or earlier • Cleaning `Inf` values from an R dataframe • Aggregate / summarize multiple variables per group (e.g. sum, mean) • How do you delete a column by name in data.table?