Skip to main content

Creating a List in R

Practice Lists in R by using course material from DataCamp's Intro to R course.
Sep 27, 2018  · 3 min read

If you want to take our free Intro to R course, here is the link.

Creating a list

Let us create our first list! To construct a list you use the function list():

my_list <- list(comp1, comp2 ...)

The arguments to the list function are the list components. Remember, these components can be matrices, vectors, other lists, ...

Instructions

Construct a list, named my_list, that contains the variables my_vector, my_matrix and my_df as list components.

eyJsYW5ndWFnZSI6InIgIiwicHJlX2V4ZXJjaXNlX2NvZGUiOiJcbiIsInNh bXBsZSI6IlxuIyBWZWN0b3Igd2l0aCBudW1lcmljcyBmcm9tIDEgdXAgdG8g MTBcbiAgICAgICAgbXlfdmVjdG9yIDwtIDE6MTBcblxuICAgICAgICAjIE1h dHJpeCB3aXRoIG51bWVyaWNzIGZyb20gMSB1cCB0byA5XG4gICAgICAgIG15 X21hdHJpeCA8LSBtYXRyaXgoMTo5LCBuY29sID0gMylcblxuICAgICAgICAj IEZpcnN0IDEwIGVsZW1lbnRzIG9mIHRoZSBidWlsdC1pbiBkYXRhIGZyYW1l IG10Y2Fyc1xuICAgICAgICBteV9kZiA8LSBtdGNhcnNbMToxMCxdXG5cbiAg ICAgICAgIyBDb25zdHJ1Y3QgbGlzdCB3aXRoIHRoZXNlIGRpZmZlcmVudCBl bGVtZW50czpcbiAgICAgICAgbXlfbGlzdCA8LSIsInNvbHV0aW9uIjoiXG4j IFZlY3RvciB3aXRoIG51bWVyaWNzIGZyb20gMSB1cCB0byAxMFxuICAgICAg ICBteV92ZWN0b3IgPC0gMToxMFxuXG4gICAgICAgICMgTWF0cml4IHdpdGgg bnVtZXJpY3MgZnJvbSAxIHVwIHRvIDlcbiAgICAgICAgbXlfbWF0cml4IDwt IG1hdHJpeCgxOjksIG5jb2wgPSAzKVxuXG4gICAgICAgICMgRmlyc3QgMTAg ZWxlbWVudHMgb2YgdGhlIGJ1aWx0LWluIGRhdGEgZnJhbWUgbXRjYXJzXG4g ICAgICAgIG15X2RmIDwtIG10Y2Fyc1sxOjEwLF1cblxuICAgICAgICAjIENv bnN0cnVjdCBsaXN0IHdpdGggdGhlc2UgZGlmZmVyZW50IGVsZW1lbnRzOlxu ICAgICAgICBteV9saXN0IDwtIGxpc3QobXlfdmVjdG9yLCBteV9tYXRyaXgs IG15X2RmKSIsInNjdCI6IlxubXNnID0gXCJEbyBub3QgcmVtb3ZlIG9yIGNo YW5nZSB0aGUgZGVmaW5pdGlvbiBvZiB0aGUgdmFyaWFibGVzIGBteV92ZWN0 b3JgLCBgbXlfbWF0cml4YCBvciBgbXlfZGZgIVwiXG4gICAgICAgIHRlc3Rf b2JqZWN0KFwibXlfdmVjdG9yXCIsIHVuZGVmaW5lZF9tc2cgPSBtc2csIGlu Y29ycmVjdF9tc2cgPSBtc2cpXG4gICAgICAgIHRlc3Rfb2JqZWN0KFwibXlf bWF0cml4XCIsIHVuZGVmaW5lZF9tc2cgPSBtc2csIGluY29ycmVjdF9tc2cg PSBtc2cpXG4gICAgICAgIHRlc3Rfb2JqZWN0KFwibXlfZGZcIiwgdW5kZWZp bmVkX21zZyA9IG1zZywgaW5jb3JyZWN0X21zZyA9IG1zZylcbiAgICAgICAg dGVzdF9vYmplY3QoXCJteV9saXN0XCIsXG4gICAgICAgICAgICAgICAgICAg IGluY29ycmVjdF9tc2cgPSBcIkl0IGxvb2tzIGxpa2UgYG15X2xpc3RgIGRv ZXMgbm90IGNvbnRhaW4gdGhlIGNvcnJlY3QgZWxlbWVudHMuIE1ha2Ugc3Vy ZSB0byBwYXNzIHRoZSB2YXJpYWJsZXMgYG15X3ZlY3RvcmAsIGBteV9tYXRy aXhgIGFuZCBgbXlfZGZgIHRvIHRoZSBgbGlzdCgpYCBmdW5jdGlvbiwgc2Vw YXJhdGVkIGJ5IGNvbW1hcywgaW4gdGhpcyBvcmRlci5cIilcbiAgICAgICAg c3VjY2Vzc19tc2coXCJXb25kZXJmdWwhIEhlYWQgb3ZlciB0byB0aGUgbmV4 dCBleGVyY2lzZS5cIikiLCJoaW50IjoiXG4gIFVzZSB0aGUgYGxpc3QoKWAg ZnVuY3Rpb24gd2l0aCBgbXlfdmVjdG9yYCwgYG15X21hdHJpeGAgYW5kIGBt eV9kZmAgYXMgYXJndW1lbnRzIHNlcGFyYXRlZCBieSBhIGNvbW1hLiJ9

Creating a named list

Well done, you're on a roll!

Just like on your to-do list, you want to avoid not knowing or remembering what the components of your list stand for. That is why you should give names to them:

my_list <- list(name1 = your_comp1,
                name2 = your_comp2)

This creates a list with components that are named name1, name2, and so on. If you want to name your lists after you've created them, you can use the names() function as you did with vectors. The following commands are fully equivalent to the assignment above:

my_list <- list(your_comp1, your_comp2)
names(my_list) <- c("name1", "name2")

Instructions

  • Change the code of the previous exercise (see editor) by adding names to the components. Use for my_vector the name vec, for my_matrix the name mat and for my_df the name df.
  • Print out my_list so you can inspect the output.
eyJsYW5ndWFnZSI6InIgIiwicHJlX2V4ZXJjaXNlX2NvZGUiOiJcbiIsInNh bXBsZSI6IlxuIyBWZWN0b3Igd2l0aCBudW1lcmljcyBmcm9tIDEgdXAgdG8g MTBcbiAgICAgICAgbXlfdmVjdG9yIDwtIDE6MTBcblxuICAgICAgICAjIE1h dHJpeCB3aXRoIG51bWVyaWNzIGZyb20gMSB1cCB0byA5XG4gICAgICAgIG15 X21hdHJpeCA8LSBtYXRyaXgoMTo5LCBuY29sID0gMylcblxuICAgICAgICAj IEZpcnN0IDEwIGVsZW1lbnRzIG9mIHRoZSBidWlsdC1pbiBkYXRhIGZyYW1l IG10Y2Fyc1xuICAgICAgICBteV9kZiA8LSBtdGNhcnNbMToxMCxdXG5cbiAg ICAgICAgIyBBZGFwdCBsaXN0KCkgY2FsbCB0byBnaXZlIHRoZSBjb21wb25l bnRzIG5hbWVzXG4gICAgICAgIG15X2xpc3QgPC0gbGlzdChteV92ZWN0b3Is IG15X21hdHJpeCwgbXlfZGYpXG5cbiAgICAgICAgIyBQcmludCBvdXQgbXlf bGlzdCIsInNvbHV0aW9uIjoiXG4jIFZlY3RvciB3aXRoIG51bWVyaWNzIGZy b20gMSB1cCB0byAxMFxuICAgICAgICBteV92ZWN0b3IgPC0gMToxMFxuXG4g ICAgICAgICMgTWF0cml4IHdpdGggbnVtZXJpY3MgZnJvbSAxIHVwIHRvIDlc biAgICAgICAgbXlfbWF0cml4IDwtIG1hdHJpeCgxOjksIG5jb2wgPSAzKVxu XG4gICAgICAgICMgRmlyc3QgMTAgZWxlbWVudHMgb2YgdGhlIGJ1aWx0LWlu IGRhdGEgZnJhbWUgbXRjYXJzXG4gICAgICAgIG15X2RmIDwtIG10Y2Fyc1sx OjEwLF1cblxuICAgICAgICAjIEFkYXB0IGxpc3QoKSBjYWxsIHRvIGdpdmUg dGhlIGNvbXBvbmVudHMgbmFtZXNcbiAgICAgICAgbXlfbGlzdCA8LSBsaXN0 KHZlYyA9IG15X3ZlY3RvciwgbWF0ID0gbXlfbWF0cml4LCBkZiA9IG15X2Rm KVxuXG4gICAgICAgICMgUHJpbnQgb3V0IG15X2xpc3RcbiAgICAgICAgbXlf bGlzdCIsInNjdCI6IlxubXNnID0gXCJEbyBub3QgcmVtb3ZlIG9yIGNoYW5n ZSB0aGUgZGVmaW5pdG9uIG9mIHRoZSB2YXJpYWJsZXMgYG15X3ZlY3RvcmAs IGBteV9tYXRyaXhgIG9yIGBteV9kZmAhXCJcbiAgICAgICAgdGVzdF9vYmpl Y3QoXCJteV92ZWN0b3JcIiwgdW5kZWZpbmVkX21zZyA9IG1zZywgaW5jb3Jy ZWN0X21zZyA9IG1zZylcbiAgICAgICAgdGVzdF9vYmplY3QoXCJteV9tYXRy aXhcIiwgdW5kZWZpbmVkX21zZyA9IG1zZywgaW5jb3JyZWN0X21zZyA9IG1z ZylcbiAgICAgICAgdGVzdF9vYmplY3QoXCJteV9kZlwiLCB1bmRlZmluZWRf bXNnID0gbXNnLCBpbmNvcnJlY3RfbXNnID0gbXNnKVxuICAgICAgICB0ZXN0 X29iamVjdChcIm15X2xpc3RcIixcbiAgICAgICAgICAgICAgICAgICAgaW5j b3JyZWN0X21zZyA9IFwiSXQgbG9va3MgbGlrZSBgbXlfbGlzdGAgZG9lcyBu b3QgY29udGFpbiB0aGUgY29ycmVjdCBlbGVtZW50cy5cIilcbiAgICAgICAg dGVzdF9vYmplY3QoXCJteV9saXN0XCIsIGVxX2NvbmRpdGlvbiA9IFwiZXF1 YWxcIixcbiAgICAgICAgICAgICAgICAgICAgaW5jb3JyZWN0X21zZyA9IFwi SXQgbG9va3MgbGlrZSBgbXlfbGlzdGAgZG9lcyBub3QgY29udGFpbiB0aGUg Y29ycmVjdCBuYW1pbmcgZm9yIHRoZSBjb21wb25lbnRzLiBNYWtlIHN1cmUg eW91IHVzZSB0aGUgbmFtZXMgYHZlY2AsIGBtYXRgIGFuZCBgZGZgLCByZXNw ZWN0aXZlbHkuIENoZWNrIG91dCB0aGUgaGludCBpZiB5b3UncmUgc3RydWdn bGluZy5cIik7XG4gICAgICAgIHRlc3Rfb3V0cHV0X2NvbnRhaW5zKFwibXlf bGlzdFwiLCBpbmNvcnJlY3RfbXNnID0gXCJEb24ndCBmb3JnZXQgdG8gcHJp bnQgYG15X2xpc3RgIHRvIHRoZSBjb25zb2xlISBTaW1wbHkgYWRkIGBteV9s aXN0YCBvbiBhIG5ldyBsaW5lIGluIHRoZSBlZGl0b3IuXCIpXG4gICAgICAg IHN1Y2Nlc3NfbXNnKFwiR3JlYXQhIE5vdCBvbmx5IGRvIHlvdSBrbm93IGhv dyB0byBjb25zdHJ1Y3QgbGlzdHMgbm93LCB5b3UgY2FuIGFsc28gbmFtZSB0 aGVtOyBhIHNraWxsIHRoYXQgd2lsbCBwcm92ZSBtb3N0IHVzZWZ1bCBpbiBw cmFjdGljZS4gQ29udGludWUgdG8gdGhlIG5leHQgZXhlcmNpc2UuXCIpIiwi aGludCI6IlxuVGhlIGZpcnN0IG1ldGhvZCBvZiBhc3NpZ25pbmcgbmFtZXMg dG8geW91ciBsaXN0IGNvbXBvbmVudHMgaXMgdGhlIGVhc2llc3QuIEl0IHN0 YXJ0cyBsaWtlIHRoaXM6XG4gICAgICAgICAgICAgICAgICBgYGBcbiAgICAg ICAgICAgICAgICAgIG15X2xpc3QgPC0gbGlzdCh2ZWMgPSBteV92ZWN0b3Ip XG4gICAgICAgICAgICAgICAgICBgYGBcbiAgICAgICAgICAgICAgQWRkIHRo ZSBvdGhlciB0d28gY29tcG9uZW50cyBpbiBhIHNpbWlsYXIgZmFzaGlvbi4i fQ==

Creating a named list (2)

Being a huge movie fan (remember your job at LucasFilms), you decide to start storing information on good movies with the help of lists.

Start by creating a list for the movie "The Shining". We have already created the variables mov, act and rev in your R workspace. Feel free to check them out in the console.

Instructions

Complete the code on the right to create shining_list; it contains three elements:

  • moviename: a character string with the movie title (stored in mov)
  • actors: a vector with the main actors' names (stored in act)
  • reviews: a data frame that contains some reviews (stored in rev)

Do not forget to name the list components accordingly (names are moviename, actors and reviews).

eyJsYW5ndWFnZSI6InIgIiwicHJlX2V4ZXJjaXNlX2NvZGUiOiJcbiAgbW92 IDwtIFwiVGhlIFNoaW5pbmdcIlxuICAgICAgICBhY3QgICAgICA8LSBjKFwi SmFjayBOaWNob2xzb25cIixcIlNoZWxsZXkgRHV2YWxsXCIsXCJEYW5ueSBM bG95ZFwiLFwiU2NhdG1hbiBDcm90aGVyc1wiLFwiQmFycnkgTmVsc29uXCIp XG4gICAgICAgIHNvdXJjZXMgICAgIDwtIGMoXCJJTURiMVwiLFwiSU1EYjJc IixcIklNRGIzXCIpXG4gICAgICAgIGNvbW1lbnRzICAgIDwtIGMoXCJCZXN0 IEhvcnJvciBGaWxtIEkgSGF2ZSBFdmVyIFNlZW5cIixcIkEgdHJ1bHkgYnJp bGxpYW50IGFuZCBzY2FyeSBmaWxtIGZyb20gU3RhbmxleSBLdWJyaWNrXCIs XCJBIG1hc3RlcnBpZWNlIG9mIHBzeWNob2xvZ2ljYWwgaG9ycm9yXCIpXG4g ICAgICAgIHNjb3JlcyAgICAgIDwtIGMoNC41LDQsNSlcbiAgICAgICAgcmV2 ICAgICA8LSBkYXRhLmZyYW1lKHNjb3Jlcywgc291cmNlcywgY29tbWVudHMp XG4gICAgICAgIHJtKHNjb3Jlcywgc291cmNlcywgY29tbWVudHMpIiwic2Ft cGxlIjoiXG4jIFRoZSB2YXJpYWJsZXMgbW92LCBhY3QgYW5kIHJldiBhcmUg YXZhaWxhYmxlXG5cbiAgICAgICAgIyBGaW5pc2ggdGhlIGNvZGUgdG8gYnVp bGQgc2hpbmluZ19saXN0XG4gICAgICAgIHNoaW5pbmdfbGlzdCA8LSBsaXN0 KG1vdmllbmFtZSA9IG1vdikiLCJzb2x1dGlvbiI6IlxuICAjIFRoZSB2YXJp YWJsZXMgbW92LCBhY3QgYW5kIHJldiBhcmUgYXZhaWxhYmxlXG5cbiAgICAg ICAgIyBGaW5pc2ggdGhlIGNvZGUgdG8gYnVpbGQgc2hpbmluZ19saXN0XG4g ICAgICAgIHNoaW5pbmdfbGlzdCA8LSBsaXN0KG1vdmllbmFtZSA9IG1vdiwg YWN0b3JzID0gYWN0LCByZXZpZXdzID0gcmV2KSIsInNjdCI6IlxuICBtc2cg PSBcIkRvIG5vdCByZW1vdmUgb3IgY2hhbmdlIHRoZSBkZWZpbml0aW9uIG9m IHRoZSBwcmUtc2V0IHZhcmlhYmxlcyFcIlxuICAgICAgICBsYXBwbHkoYyhc Im1vdlwiLCBcInJldlwiLCBcImFjdFwiKSwgdGVzdF9vYmplY3QsIHVuZGVm aW5lZF9tc2cgPSBtc2csIGluY29ycmVjdF9tc2cgPSBtc2cpXG4gICAgICAg IHRlc3Rfb2JqZWN0KFwic2hpbmluZ19saXN0XCIsXG4gICAgICAgICAgICAg ICAgICAgIGluY29ycmVjdF9tc2cgPSBcIkl0IGxvb2tzIGxpa2UgYHNoaW5p bmdfbGlzdGAgZG9lcyBub3QgY29udGFpbiB0aGUgY29ycmVjdCBlbGVtZW50 czogdGhlIGZpcnN0IGVsZW1lbnQgc2hvdWxkIGJlIGBtb3ZgLCB0aGUgc2Vj b25kIGVsZW1lbnQgYGFjdGAsIGFuZCB0aGUgdGhpcmQgYHJldmAuXCIpXG4g ICAgICAgIHRlc3Rfb2JqZWN0KFwic2hpbmluZ19saXN0XCIsIGVxX2NvbmRp dGlvbiA9IFwiZXF1YWxcIixcbiAgICAgICAgICAgICAgICAgICAgaW5jb3Jy ZWN0X21zZyA9IFwiSXQgbG9va3MgbGlrZSBgc2hpbmluZ19saXN0YCBkb2Vz IG5vdCBjb250YWluIHRoZSBjb3JyZWN0IG5hbWluZyBmb3IgdGhlIGNvbXBv bmVudHM6IG5hbWUgdGhlIGZpcnN0IGVsZW1lbnQgYG1vdmllbmFtZWAsIHRo ZSBzZWNvbmQgZWxlbWVudCBgYWN0b3JzYCwgYW5kIHRoZSB0aGlyZCBlbGVt ZW50IGByZXZpZXdzYC5cIik7XG4gICAgICAgIHN1Y2Nlc3NfbXNnKFwiV29u ZGVyZnVsISBZb3Ugbm93IGtub3cgaG93IHRvIGNvbnN0cnVjdCBhbmQgbmFt ZSBsaXN0cy4gQXMgaW4gdGhlIHByZXZpb3VzIGNoYXB0ZXJzLCBsZXQncyBs b29rIGF0IGhvdyB0byBzZWxlY3QgZWxlbWVudHMgZm9yIGxpc3RzLiBIZWFk IG92ZXIgdG8gdGhlIG5leHQgZXhlcmNpc2VcIikiLCJoaW50IjoiXG5gYHNo aW5pbmdfbGlzdCA8LSBsaXN0KG1vdmllbmFtZSA9IG1vdilgYCBpcyBvbmx5 IHBhcnQgb2YgdGhlIHNvbHV0aW9uOyBpdCdzIHlvdXIgam9iIHRvIGFsc28g YWRkIGBhY3RgIGFuZCBgcmV2YCB0byB0aGUgbGlzdCwgd2l0aCB0aGUgYXBw cm9wcmlhdGUgbmFtZXMuIn0=


If you want to learn more from this course, here is the link.

Check out our Data Types in R tutorial.

Topics
R
Data Science
Data Analysis

R Courses

course

Introduction to R

4 hr
2.7M
Master the basics of data analysis in R, including vectors, lists, and data frames, and practice R with real data sets.
See DetailsRight Arrow
Start Course
See MoreRight Arrow
Related

tutorial

Basic Programming Skills in R

Practice basic programming skills in R by using course material from DataCamp's free Model a Quantitative Trading Strategy in R course.
Ryan Sheehy's photo

Ryan Sheehy

5 min

tutorial

Introduction to Data frames in R

This tutorial takes course material from DataCamp's Introduction to R course and allows you to practice data frames.
Ryan Sheehy's photo

Ryan Sheehy

5 min

tutorial

Utilities in R Tutorial

Learn about several useful functions for data structure manipulation, nested-lists, regular expressions, and working with times and dates in the R programming language.
Aditya Sharma's photo

Aditya Sharma

18 min

tutorial

Mastering Data Structures in the R Programming Language

Read our comprehensive guide on how to work with data structures in R programming: vectors, lists, arrays, matrices, factors, and data frames.
Vikash Singh's photo

Vikash Singh

6 min

tutorial

Factor Levels in R

This tutorial takes course material from DataCamp's free Intro to R course and allows you to practice Factors.
Ryan Sheehy's photo

Ryan Sheehy

6 min

tutorial

Data Frames in R

This tutorial takes course material from DataCamp's Introduction to R for Finance course and allows you to practice Data Frames.
Ryan Sheehy's photo

Ryan Sheehy

4 min

See MoreSee More