Check the documentation!

How do we do this?

?par
??plot

(Remember, you can spend 2 hours searching the web in order to save 15 minutes of reading the documentation).

No really, read the docs

2 main aspects of documentation:

1. Function reference
2. Vignettes

CRAN can be a good place to start.

tidyr example

Read your error messages

They are often telling you something important.

Informative error message I ignored

Still, error messages can be confusing

Other help options

RStudio Community

Other help options

R4DS community

Other help options

Stack overflow

Read the source code

(this will help improve your coding, too)

How to find source code

• Type the function name in the console without parentheses:

lm

[suppressed output because it is long]

• Sometimes this is not informative

c

## function (...)  .Primitive("c")

subset

## function (x, ...) 
## UseMethod("subset")
## <bytecode: 0x55f9840d3de0>
## <environment: namespace:base>

`[`

## .Primitive("[")

Use 'lookup' to find what you need

(Prior to 'lookup', finding source code was a real bugger

lookup checks CRAN, Bioconductor and GitHub!

lookup::lookup(`[`)

Miscellaneous R tip

How to find other methods associated with an R object

All R objects have a class assigned to them:

y <- rnorm(20); x <- y + rnorm(20)
m <- lm(y ~ x)
class(m)

## [1] "lm"

Once you know the object class, you can search on methods written for that class.

methods(class = "lm")

##  [1] add1           alias          anova          case.names     coerce        
##  [6] confint        cooks.distance deviance       dfbeta         dfbetas       
## [11] drop1          dummy.coef     effects        extractAIC     family        
## [16] formula        hatvalues      influence      initialize     kappa         
## [21] labels         logLik         model.frame    model.matrix   nobs          
## [26] plot           predict        print          proj           qr            
## [31] residuals      rstandard      rstudent       show           simulate      
## [36] slotsFromS3    summary        variable.names vcov          
## see '?methods' for accessing help and source code