For more information on individual commands, see the appropriate Appendix for usage, and refer to the help pages available from within R (see Getting Help with R). Commands below indicated as [local] are not a regular part of R, but can be created by you with a local call to the function command as shown in the corresponding document.
| Command | Comment | Document(s) |
| Descriptive Statistics | ||
| IQR | inter-quartile range | 2 |
| length | length of data | 2,5,7,10,11 |
| max | maximum of data | 5 |
| mean | mean of data | I,6,7,12 |
| median | median of data | 10,11 |
| range | range of data | 2,7 |
| sd | SD of data | I,2,6,7 |
| stem | stem-leaf diagram | I,2 |
| summary | summary of object | 2,14 |
| var | variance of data | 2,5,6,7,10 |
| Modify Data | ||
| abs | absolute value | 6,10,11 |
| diff | difference of values | 2 |
| log10 | log base 10 of values | 2 |
| sqrt | square root of values | 6,7,9,10 |
| sum | sum of values | 6,7 |
| Plots | ||
| abline | draw y=a+bx line | 7,9 |
| hist | histogram | I,2,5,9 |
| lines | draw lines on plot | 5,7 |
| par | set plot parameters | A |
| plot | plot a data object | 7,9,11,14 |
| qqnorm | normal quantile-quantile plot | 8 |
| Probability Distributions | ||
| dbinom | binomial distribution | 4 |
| dchisq | chi-square distribution | 5 |
| dpois | Poisson distribution | 4 |
| pbinom | binomial probability | 4 |
| pchisq | chi-square probability | 5,6 |
| pnorm | normal probability | 4,6,9 |
| pt | T probability | 6 |
| rnorm | draw normal samples | 5,6,7,9 |
| qchisq | chi-square probability | 5,7 |
| qnorm | normal quantiles | 4,7,9 |
| qt | T quantiles | 6 |
| sample | draw samples from distribution | 5 |
| Inference: Testing & C.I.s | ||
| anova | show anova table | 11,14 |
| chisq.test | chi-square test | 13 |
| cor.test | correlation test | 15 |
| kruskal.test | non-parametric analysis of variance | 11 |
| levene.test [local] | Levene's test of variance | 10,11 |
| lm | fit a linear model | 11,14 |
| norm.interval [local] | C.I. for mean with known variance | 7 |
| oneway.test | one-way analysis of variance | 11 |
| pairwise.t.test | All pairs T-tests of mean | 11,12 |
| predict | predicted values | 14 |
| prop.test | test of proportion | 6,7,10 |
| p.table [local] | table p-values from pairwise tests | 12 |
| t.test | T-test of mean | 6,7,9,10 |
| var.interval [local] | C.I. for variance | 7 |
| wilcox.test | non-parametric two-sample test | 10 |
| Read & Print Data | ||
| cat | catenate (print) an object | 11 |
| print an object | 11 | |
| read.table | read data table from file | I,11,12,14,15 |
| Arrange Data | ||
| apply | apply command to matrix | 5,6,7,9 |
| c | combine data together | I,2,5,6,7,8,9,10,11,13,14 |
| cbind | bind columns of data | 9,12 |
| data.frame | create data frame | 8,11,12,14 |
| dimnames | dimension names of matrix | 12 |
| duplicated | find duplicated values | 10,11 |
| factor | create a factor | 11 |
| is.na | is data missing (NA)? | 12 |
| lapply | apply command to list | 11 |
| list | create a list object | 12 |
| matrix | create matrix of values | 5,6,7,9,13 |
| order | show order of sort | 12 |
| rep | repeat values | 11 |
| seq | create sequence of values | 5,9,11 |
| sort | sort data | 10,11,12 |
| rbind | bind rows of data | 12 |
| split | split up list | 11 |
| t | transpose matrix | 12 |
| tapply | apply command by factor levels | 11,12 |
| unsplit | unsplit to list | 11 |
| Using R: Help, Quit, etc. | ||
| for | for looping command | 7,11 |
| function | create a function | 6,7,9,10,11,12 |
| help | help on command | I |
| help.search | help on topic | I |
| help.start | start HTML help | I |
| if | if conditional command | 10,11 |
| source | source commands from file | A |
| q | quit | I |