An R Function Finder
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  Following is an alphabetical list of procedures you may wish to carry out, along with
  some of the associated functions that may be helpful in that respect. This should in
  NO WAY be considered a complete listing of R functions! Only functions in the base R
  default installation are included here (and even as such the list is far from com-
  plete). There are MANY more functions and procedures in the optional packages. To get
  more information on any of the functions, just request the help page, for example,
  help(mean). Or refer to the R Function Reference found at this site. This is a plain
  text document, so use the back button on your browser to return to the previous page.
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PROCEDURE                         FUNCTIONS
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absolute value                    abs()
addition                          sum(), +
analysis of covariance            aov(), lm()
analysis of variance              aov(), anova(), oneway.test(), lm(), manova(), summary()
antilogs                          exp()
array (creation of)               array()
array (naming of dimensions)      dimnames()
autocorrelation                   acf()

bar graph                         barplot()
binomial coefficients             choose()
binomial distribution             dbinom(), pbinom(), qbinom(), rbinom()
binomial test                     binom.test()
Bonferroni tests                  pairwise.t.test()
bootstrapping                     boot() (boot library)
Box-Cox transformations           boxcox() (MASS library)
box plots                         boxplot()

categorical variables             see factor
chi-square distribution           dchisq(), pchisq(), qchisq(), rchisq()
chi-square goodness of fit test   chisq.test()
chi-square independence test      chisq.test()
colors on a graph                 colors(), rainbow(), heat.colors(), topo.colors()
combinations                      choose()
confidence intervals              t.test(), confint()
contingency table (creating)      table(), xtabs(), array()
contingency table (naming dims)   colnames(), rownames(), dimnames()
contingency table (working with)  addmargins(), margin.table(), prop.table(), ftable()
contrasts (checking, setting)     contrasts()
Cook's distance                   cooks.distance()
correlation                       cor()
correlation matrix                cor()
correlation significance test     cor.test()
covariance matrix                 cor(), cov(), var(), cov2cor()
cross tabulation                  xtabs(), table()

data (entering)                   c(), scan(), read.table()
data (retrieving built in)        data()
data frame (access to variables)  with(), attach(), detach(), dfname$varname
data frame (coerce to)            as.data.frame(), as.data.frame.table()
data frame (creating)             data.frame()
data frame (descriptive stats)    summary()
data frame (info about)           dim(), names(), str(), head(), tail()
data frame (naming rows & cols)   rownames(), colnames()
data frame (sorting of)           order()
data frame (working with)         order(), select(), subset(), stack()
dates                             date(), difftime()
deciles                           quantile()
descriptive statistics (simple)   summary(), fivenum(), mean(), median(), var(), sd()
descriptive statistics by group   by(), tapply(), aggregate(), model.tables()
division			              /
draw on an existing graph         abline(), lines(), points(), text(), curve(), title()

exponentiation                    ^, exp()

F distribution                    df(), pf(), qf(), rf()
factor (creating)                 factor(), gl()
factor (info about)               summary(), levels()
factor (levels)                   levels(), relevel(), factor()
factor (value labels)             factor()
factorials                        factorial()
files (reading in)                load(), read.table(), read.csv(), source()
files (saving)                    save(), save.image(), write.table(), write.csv()
Fisher Exact test                 fisher.test()
Fisher LSD tests                  pairwise.t.test()
flat table                        ftable()
frequency distribution            table(), stem(), cut(), hist(), density()
Friedman Rank Sum test            friedman.test()
function (creating)               function()

generalized linear models         glm()
graphics window (opening)         plot.new(), quartz() (Mac only), windows() (Win only)
graphing                          plot(), barplot(), boxplot(), hist(), scatter.smooth(),
                                  interaction.plot(), stripchart(), lines(), points(),
                                  curve(), identify(), locator(), text()

help                              help(), help.search(), apropos(), args()
histogram                         hist()
homogeneity of variance test      bartlett.test(), fligner.test()

influence measures                cooks.distance(), influence.measures(), etc.
interaction line graph            interaction.plot()
interquartile range               IQR(), summary(), fivenum(), quantile()

kernel density smoothing          density(), plot(density())
Kolmogorov-Smirnov test           ks.test()
Kruskal-Wallis test               kruskal.test()

legend (adding to a graph)        legend()
lines (drawing on a graph)        abline(), lines(), curve()
list (creation of)                list()
log linear analysis               loglm() (MASS library), glm(), loglin()
logarithm                         log(), log10(), log2(), exp()
logical operations                all(), any(), which(), ifelse(), & (and), | (or)
logistic regression               glm()
looping                           for(), etc.

Mann-Whitney test                 wilcox.test()
marginal sums (contingency table) addmargins()
matrix (coerce to)                as.matrix()
matrix (creation of)              matrix(), cbind(), rbind()
matrix (info about)               dim(), head(), colnames(), rownames()
matrix (naming rows & cols)       colnames(), rownames(), dimnames()
matrix operations                 colMeans(), rowMeans(), t(), %*%
maximum                           max(), range(), summary(), fivenum()
mean (arithmetic)                 mean(), summary()
mean (harmonic of vector)         1/mean(1/vector)
mean (weighted)                   weighted.mean()
median                            median(), summary()
median absolute deviation         mad()
minimum                           min(), range(), summary(), fivenum()
missing values                    NA, na.omit
mosaic plot                       mosaicplot()
multiple regression               lm(), update(), step(), summary()
multiplication                    prod(), *
multivariate anova                manova()

normal distribution               dnorm(), pnorm(), qnorm(), rnorm()
normal distribution (testing)     shapiro.test(), ks.test(), qqnorm()
normal probability (QQ) plot      qqplot(), qqnorm(), qqline()

objects (what kind are they?)     class()

package management                search(), install.packages(), installed.packages()
percentiles                       quantile()
pie chart                         pie()
points (plotting on a graph)      points()
Poisson distribution              dpois(), ppois(), qpois(), rpois()
post hoc tests                    TukeyHSD(), pairwise.t.test()
power calculations                power.prop.test(), power.t.test(), power.anova.test()
prediction from regression model  predict()
profile plot                      interaction.plot()
proportions                       prop.table()
proportion test                   prop.test(), binom.test()

quartiles                         quantile(), summary(), fivenum()
quantiles (arbitrary)             quantile()
quit R                            quit()

random numbers                    rnorm(), runif(), etc.
range                             range(), summary(), fivenum()
regression coefficients           coef(), coefficients(), confint()
regression confidence intervals   confint()
regression (simple, multiple)     lm(), coef(), fitted(), residuals(), summary()
regression diagnostic plots       plot(lm_model)
regression influence measures     cooks.distance(), influence.measures(), etc.
regression line (drawing)         abline()
regression model (updating)       update(), step()
regression (predicting from)      predict()
regression (stepwise)             step()
repeating values (create)         rep()
rounding                          round()

sample size                       length()
samples (simulation)              sample(), rnorm(), runif()
saving files (see files)          save(), save.image(), write.table(), write.csv()
scatterplot                       plot(), scatter.smooth()
scatterplot matrix                pairs(), plot()
scripts (reading in)              source()
search path                       search(), attach(), detach(), library(), require()
sequences (regular)               seq()
Shapiro-Wilk test                 shapiro.test()
smoothing                         density(), plot(density()), scatter.smooth(), lowess()
sorting                           sort(), order(), rank()
Spearman correlation              cor()
square root                       sqrt()
standard deviation                sd()
stem-and-leaf display             stem()
strip chart                       stripchart()
Student's t-test                  t.test()
square root                       sqrt()
subsetting data                   subset(), select()
subtraction                       diff(), -
sum                               sum()
sum of squares (of vector)        sum(vector^2)-sum(vector)^2/length(vector)

t distribution                    dt(), pt(), qt(), rt()
t-test				              t.test(), pairwise.t.test()
tables (creating)                 table(), array(), (see also matrix, contingency table)
tables (working with)             prop.table(), ftable(), (see also contingency table)
test (adding to a graph)          text()
titles and labels on a graph      title()
trig functions                    sin(), cos(), tan(), asin(), etc.
Tukey's HSD test                  TukeyHSD()

uniform distribution              dunif(), punif(), qunif(), runif()

variance                          var()
variance significance test        var.test() (see also homogeneity tests)
vector (creation of)              c(), seq(), rep(), scan(), numeric()
vector (info about)               summary(), length(), head(), class()

weighted mean                     weighted.mean()
Wilcoxin tests                    wilcox.test()
working directory                 dir(), getwd(), setwd()
workspace functions               ls(), rm()