How to obtain a position of last non-zero element The 2019 Stack Overflow Developer Survey Results Are In Unicorn Meta Zoo #1: Why another podcast? Announcing the arrival of Valued Associate #679: Cesar Manara The Ask Question Wizard is Live! Data science time! April 2019 and salary with experienceHow to trim leading and trailing whitespace?How do I replace NA values with zeros in an R dataframe?data.table vs dplyr: can one do something well the other can't or does poorly?Calculate days since last event in REfficient way of taking the max date within groupsTurn off verbose messages when loading tidyverse using library() functionColumn name of last non-NA row per row; using tidyverse solution?Filtering data relative to first and last occurance of an eventdplyr approach to get the last row number with a positive valueA code to imput missing values with linear dependency

Do working physicists consider Newtonian mechanics to be "falsified"?

What information about me do stores get via my credit card?

Working through the single responsibility principle (SRP) in Python when calls are expensive

Is this wall load bearing? Blueprints and photos attached

Drawing vertical/oblique lines in Metrical tree (tikz-qtree, tipa)

Accepted by European university, rejected by all American ones I applied to? Possible reasons?

How to read αἱμύλιος or when to aspirate

Python - Fishing Simulator

Didn't get enough time to take a Coding Test - what to do now?

Can withdrawing asylum be illegal?

Sort list of array linked objects by keys and values

Why not take a picture of a closer black hole?

how can a perfect fourth interval be considered either consonant or dissonant?

Make it rain characters

Why can't wing-mounted spoilers be used to steepen approaches?

First use of “packing” as in carrying a gun

Can each chord in a progression create its own key?

Can the DM override racial traits?

One-dimensional Japanese puzzle

Was credit for the black hole image misappropriated?

For what reasons would an animal species NOT cross a *horizontal* land bridge?

Huge performance difference of the command find with and without using %M option to show permissions

Did the new image of black hole confirm the general theory of relativity?

Is 'stolen' appropriate word?



How to obtain a position of last non-zero element



The 2019 Stack Overflow Developer Survey Results Are In
Unicorn Meta Zoo #1: Why another podcast?
Announcing the arrival of Valued Associate #679: Cesar Manara
The Ask Question Wizard is Live!
Data science time! April 2019 and salary with experienceHow to trim leading and trailing whitespace?How do I replace NA values with zeros in an R dataframe?data.table vs dplyr: can one do something well the other can't or does poorly?Calculate days since last event in REfficient way of taking the max date within groupsTurn off verbose messages when loading tidyverse using library() functionColumn name of last non-NA row per row; using tidyverse solution?Filtering data relative to first and last occurance of an eventdplyr approach to get the last row number with a positive valueA code to imput missing values with linear dependency



.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty height:90px;width:728px;box-sizing:border-box;








16















I've got a binary variable representing if event happened or not:



event <- c(0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0)


I need to obtain a variable that would indicate the time when the last event happened. The expected output would be:



last_event <- c(0, 0, 0, 0, 5, 5, 5, 5, 5, 5, 5, 5, 13, 13, 13, 13)


How can I obtain that with base R, tidyverse or any other way?










share|improve this question




























    16















    I've got a binary variable representing if event happened or not:



    event <- c(0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0)


    I need to obtain a variable that would indicate the time when the last event happened. The expected output would be:



    last_event <- c(0, 0, 0, 0, 5, 5, 5, 5, 5, 5, 5, 5, 13, 13, 13, 13)


    How can I obtain that with base R, tidyverse or any other way?










    share|improve this question
























      16












      16








      16


      1






      I've got a binary variable representing if event happened or not:



      event <- c(0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0)


      I need to obtain a variable that would indicate the time when the last event happened. The expected output would be:



      last_event <- c(0, 0, 0, 0, 5, 5, 5, 5, 5, 5, 5, 5, 13, 13, 13, 13)


      How can I obtain that with base R, tidyverse or any other way?










      share|improve this question














      I've got a binary variable representing if event happened or not:



      event <- c(0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0)


      I need to obtain a variable that would indicate the time when the last event happened. The expected output would be:



      last_event <- c(0, 0, 0, 0, 5, 5, 5, 5, 5, 5, 5, 5, 13, 13, 13, 13)


      How can I obtain that with base R, tidyverse or any other way?







      r tidyverse base






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked yesterday









      jakesjakes

      431315




      431315






















          4 Answers
          4






          active

          oldest

          votes


















          17














          Taking advantage of the fact that you have a binary vector, the following gives your desired output:



          cummax(seq_along(event) * event)





          share|improve this answer


















          • 6





            Yes! So much more elegant than my solution. I was thinking about cumulative sums but I didn’t think of multiplying the indices by the binary vector.

            – Konrad Rudolph
            yesterday






          • 3





            or without multiplication cummax(ifelse(event, seq_along(event), 0))

            – jogo
            yesterday











          • @jogo That solution makes sense if the type of event is logical. It does work even for a numeric vector due to R’s implicit conversions but … eh.

            – Konrad Rudolph
            yesterday


















          8














          Whenever you need to fill repetitions with a value, think run-length encoding.



          In this case, you can determine the run lengths and then repeat the indices of count == 0 an according number of times:



          lengths = rle(event == 0)$lengths
          nonzeros = which(event != 0)
          runs = c(0, rep(nonzeros, each = 2))
          result = rep(runs, lengths)


          Alternative, substitute the runs in the RLE and then inverse it:



          rle = rle(event == 0)
          nonzeros = which(event != 0)
          rle$values = c(0, rep(nonzeros, each = 2))
          result = inverse.rle(rle)





          share|improve this answer






























            1














            You can also do somthing like this-



            > zero.locf <- function(x) 
            v <- x!=0
            c(0, x[v])[cumsum(v)+1]


            > zero.locf(1:length(event)*event)

            [1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13





            share|improve this answer






























              1














              Another option is to find the index where event == 1 and repeat it based on length.



              rep(c(0, which(event == 1)), tapply(event, cumsum(event == 1), length))
              #[1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13





              share|improve this answer























                Your Answer






                StackExchange.ifUsing("editor", function ()
                StackExchange.using("externalEditor", function ()
                StackExchange.using("snippets", function ()
                StackExchange.snippets.init();
                );
                );
                , "code-snippets");

                StackExchange.ready(function()
                var channelOptions =
                tags: "".split(" "),
                id: "1"
                ;
                initTagRenderer("".split(" "), "".split(" "), channelOptions);

                StackExchange.using("externalEditor", function()
                // Have to fire editor after snippets, if snippets enabled
                if (StackExchange.settings.snippets.snippetsEnabled)
                StackExchange.using("snippets", function()
                createEditor();
                );

                else
                createEditor();

                );

                function createEditor()
                StackExchange.prepareEditor(
                heartbeatType: 'answer',
                autoActivateHeartbeat: false,
                convertImagesToLinks: true,
                noModals: true,
                showLowRepImageUploadWarning: true,
                reputationToPostImages: 10,
                bindNavPrevention: true,
                postfix: "",
                imageUploader:
                brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
                contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
                allowUrls: true
                ,
                onDemand: true,
                discardSelector: ".discard-answer"
                ,immediatelyShowMarkdownHelp:true
                );



                );













                draft saved

                draft discarded


















                StackExchange.ready(
                function ()
                StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f55634527%2fhow-to-obtain-a-position-of-last-non-zero-element%23new-answer', 'question_page');

                );

                Post as a guest















                Required, but never shown

























                4 Answers
                4






                active

                oldest

                votes








                4 Answers
                4






                active

                oldest

                votes









                active

                oldest

                votes






                active

                oldest

                votes









                17














                Taking advantage of the fact that you have a binary vector, the following gives your desired output:



                cummax(seq_along(event) * event)





                share|improve this answer


















                • 6





                  Yes! So much more elegant than my solution. I was thinking about cumulative sums but I didn’t think of multiplying the indices by the binary vector.

                  – Konrad Rudolph
                  yesterday






                • 3





                  or without multiplication cummax(ifelse(event, seq_along(event), 0))

                  – jogo
                  yesterday











                • @jogo That solution makes sense if the type of event is logical. It does work even for a numeric vector due to R’s implicit conversions but … eh.

                  – Konrad Rudolph
                  yesterday















                17














                Taking advantage of the fact that you have a binary vector, the following gives your desired output:



                cummax(seq_along(event) * event)





                share|improve this answer


















                • 6





                  Yes! So much more elegant than my solution. I was thinking about cumulative sums but I didn’t think of multiplying the indices by the binary vector.

                  – Konrad Rudolph
                  yesterday






                • 3





                  or without multiplication cummax(ifelse(event, seq_along(event), 0))

                  – jogo
                  yesterday











                • @jogo That solution makes sense if the type of event is logical. It does work even for a numeric vector due to R’s implicit conversions but … eh.

                  – Konrad Rudolph
                  yesterday













                17












                17








                17







                Taking advantage of the fact that you have a binary vector, the following gives your desired output:



                cummax(seq_along(event) * event)





                share|improve this answer













                Taking advantage of the fact that you have a binary vector, the following gives your desired output:



                cummax(seq_along(event) * event)






                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered yesterday









                mgiormentimgiormenti

                394111




                394111







                • 6





                  Yes! So much more elegant than my solution. I was thinking about cumulative sums but I didn’t think of multiplying the indices by the binary vector.

                  – Konrad Rudolph
                  yesterday






                • 3





                  or without multiplication cummax(ifelse(event, seq_along(event), 0))

                  – jogo
                  yesterday











                • @jogo That solution makes sense if the type of event is logical. It does work even for a numeric vector due to R’s implicit conversions but … eh.

                  – Konrad Rudolph
                  yesterday












                • 6





                  Yes! So much more elegant than my solution. I was thinking about cumulative sums but I didn’t think of multiplying the indices by the binary vector.

                  – Konrad Rudolph
                  yesterday






                • 3





                  or without multiplication cummax(ifelse(event, seq_along(event), 0))

                  – jogo
                  yesterday











                • @jogo That solution makes sense if the type of event is logical. It does work even for a numeric vector due to R’s implicit conversions but … eh.

                  – Konrad Rudolph
                  yesterday







                6




                6





                Yes! So much more elegant than my solution. I was thinking about cumulative sums but I didn’t think of multiplying the indices by the binary vector.

                – Konrad Rudolph
                yesterday





                Yes! So much more elegant than my solution. I was thinking about cumulative sums but I didn’t think of multiplying the indices by the binary vector.

                – Konrad Rudolph
                yesterday




                3




                3





                or without multiplication cummax(ifelse(event, seq_along(event), 0))

                – jogo
                yesterday





                or without multiplication cummax(ifelse(event, seq_along(event), 0))

                – jogo
                yesterday













                @jogo That solution makes sense if the type of event is logical. It does work even for a numeric vector due to R’s implicit conversions but … eh.

                – Konrad Rudolph
                yesterday





                @jogo That solution makes sense if the type of event is logical. It does work even for a numeric vector due to R’s implicit conversions but … eh.

                – Konrad Rudolph
                yesterday













                8














                Whenever you need to fill repetitions with a value, think run-length encoding.



                In this case, you can determine the run lengths and then repeat the indices of count == 0 an according number of times:



                lengths = rle(event == 0)$lengths
                nonzeros = which(event != 0)
                runs = c(0, rep(nonzeros, each = 2))
                result = rep(runs, lengths)


                Alternative, substitute the runs in the RLE and then inverse it:



                rle = rle(event == 0)
                nonzeros = which(event != 0)
                rle$values = c(0, rep(nonzeros, each = 2))
                result = inverse.rle(rle)





                share|improve this answer



























                  8














                  Whenever you need to fill repetitions with a value, think run-length encoding.



                  In this case, you can determine the run lengths and then repeat the indices of count == 0 an according number of times:



                  lengths = rle(event == 0)$lengths
                  nonzeros = which(event != 0)
                  runs = c(0, rep(nonzeros, each = 2))
                  result = rep(runs, lengths)


                  Alternative, substitute the runs in the RLE and then inverse it:



                  rle = rle(event == 0)
                  nonzeros = which(event != 0)
                  rle$values = c(0, rep(nonzeros, each = 2))
                  result = inverse.rle(rle)





                  share|improve this answer

























                    8












                    8








                    8







                    Whenever you need to fill repetitions with a value, think run-length encoding.



                    In this case, you can determine the run lengths and then repeat the indices of count == 0 an according number of times:



                    lengths = rle(event == 0)$lengths
                    nonzeros = which(event != 0)
                    runs = c(0, rep(nonzeros, each = 2))
                    result = rep(runs, lengths)


                    Alternative, substitute the runs in the RLE and then inverse it:



                    rle = rle(event == 0)
                    nonzeros = which(event != 0)
                    rle$values = c(0, rep(nonzeros, each = 2))
                    result = inverse.rle(rle)





                    share|improve this answer













                    Whenever you need to fill repetitions with a value, think run-length encoding.



                    In this case, you can determine the run lengths and then repeat the indices of count == 0 an according number of times:



                    lengths = rle(event == 0)$lengths
                    nonzeros = which(event != 0)
                    runs = c(0, rep(nonzeros, each = 2))
                    result = rep(runs, lengths)


                    Alternative, substitute the runs in the RLE and then inverse it:



                    rle = rle(event == 0)
                    nonzeros = which(event != 0)
                    rle$values = c(0, rep(nonzeros, each = 2))
                    result = inverse.rle(rle)






                    share|improve this answer












                    share|improve this answer



                    share|improve this answer










                    answered yesterday









                    Konrad RudolphKonrad Rudolph

                    404k1017921041




                    404k1017921041





















                        1














                        You can also do somthing like this-



                        > zero.locf <- function(x) 
                        v <- x!=0
                        c(0, x[v])[cumsum(v)+1]


                        > zero.locf(1:length(event)*event)

                        [1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13





                        share|improve this answer



























                          1














                          You can also do somthing like this-



                          > zero.locf <- function(x) 
                          v <- x!=0
                          c(0, x[v])[cumsum(v)+1]


                          > zero.locf(1:length(event)*event)

                          [1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13





                          share|improve this answer

























                            1












                            1








                            1







                            You can also do somthing like this-



                            > zero.locf <- function(x) 
                            v <- x!=0
                            c(0, x[v])[cumsum(v)+1]


                            > zero.locf(1:length(event)*event)

                            [1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13





                            share|improve this answer













                            You can also do somthing like this-



                            > zero.locf <- function(x) 
                            v <- x!=0
                            c(0, x[v])[cumsum(v)+1]


                            > zero.locf(1:length(event)*event)

                            [1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13






                            share|improve this answer












                            share|improve this answer



                            share|improve this answer










                            answered yesterday









                            RushabhRushabh

                            1,300221




                            1,300221





















                                1














                                Another option is to find the index where event == 1 and repeat it based on length.



                                rep(c(0, which(event == 1)), tapply(event, cumsum(event == 1), length))
                                #[1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13





                                share|improve this answer



























                                  1














                                  Another option is to find the index where event == 1 and repeat it based on length.



                                  rep(c(0, which(event == 1)), tapply(event, cumsum(event == 1), length))
                                  #[1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13





                                  share|improve this answer

























                                    1












                                    1








                                    1







                                    Another option is to find the index where event == 1 and repeat it based on length.



                                    rep(c(0, which(event == 1)), tapply(event, cumsum(event == 1), length))
                                    #[1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13





                                    share|improve this answer













                                    Another option is to find the index where event == 1 and repeat it based on length.



                                    rep(c(0, which(event == 1)), tapply(event, cumsum(event == 1), length))
                                    #[1] 0 0 0 0 5 5 5 5 5 5 5 5 13 13 13 13






                                    share|improve this answer












                                    share|improve this answer



                                    share|improve this answer










                                    answered yesterday









                                    Ronak ShahRonak Shah

                                    46.7k104269




                                    46.7k104269



























                                        draft saved

                                        draft discarded
















































                                        Thanks for contributing an answer to Stack Overflow!


                                        • Please be sure to answer the question. Provide details and share your research!

                                        But avoid


                                        • Asking for help, clarification, or responding to other answers.

                                        • Making statements based on opinion; back them up with references or personal experience.

                                        To learn more, see our tips on writing great answers.




                                        draft saved


                                        draft discarded














                                        StackExchange.ready(
                                        function ()
                                        StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f55634527%2fhow-to-obtain-a-position-of-last-non-zero-element%23new-answer', 'question_page');

                                        );

                                        Post as a guest















                                        Required, but never shown





















































                                        Required, but never shown














                                        Required, but never shown












                                        Required, but never shown







                                        Required, but never shown

































                                        Required, but never shown














                                        Required, but never shown












                                        Required, but never shown







                                        Required, but never shown







                                        -base, r, tidyverse

                                        Popular posts from this blog

                                        Creating 100m^2 grid automatically using QGIS?Creating grid constrained within polygon in QGIS?Createing polygon layer from point data using QGIS?Creating vector grid using QGIS?Creating grid polygons from coordinates using R or PythonCreating grid from spatio temporal point data?Creating fields in attributes table using other layers using QGISCreate .shp vector grid in QGISQGIS Creating 4km point grid within polygonsCreate a vector grid over a raster layerVector Grid Creates just one grid

                                        Nikolai Prilezhaev Bibliography References External links Navigation menuEarly Russian Organic Chemists and Their Legacy092774english translationRussian Biography

                                        How to link a C library to an Assembly library on Mac with clangHow do you set, clear, and toggle a single bit?Find (and kill) process locking port 3000 on MacWho is listening on a given TCP port on Mac OS X?How to start PostgreSQL server on Mac OS X?Compile assembler in nasm on mac osHow do I install pip on macOS or OS X?AFNetworking 2.0 “_NSURLSessionTransferSizeUnknown” linking error on Mac OS X 10.8C++ code for testing the Collatz conjecture faster than hand-written assembly - why?How to link a NASM code and GCC in Mac OS X?How to run x86 .asm on macOS Sierra