Calculate new values by row












0















I'd like to create a new column (val_new) in which each value is multiplied by a value in another column (val2) by row. As I want to do this for several groups I'd prefer using dplyr, but how?



dat <- data.frame(group = rep(c("A", "B"), each = 3),
val1 = c(50, NA, NA, 40, NA, NA),
val2 = c(NA, 0.5, 0.3, NA, 0.8, 0.7))

> dat
group val1 val2
1 A 50 NA
2 A NA 0.5
3 A NA 0.3
4 B 40 NA
5 B NA 0.8
6 B NA 0.7

dat %>%
group_by(group) %>%
mutate(val_new = ifelse(!is.na(val1), val1, lag(val_new) * val2))

Error in mutate_impl(.data, dots) :
Evaluation error: object 'val_new' not found.


Desired result:



# A tibble: 6 x 4
# Groups: group [2]
group val1 val2 val_new
<fct> <dbl> <dbl> <dbl>
1 A 50 NA 50
2 A NA 0.5 25
3 A NA 0.3 7.5
4 B 40 NA 40
5 B NA 0.8 32
6 B NA 0.7 22.4









share|improve this question



























    0















    I'd like to create a new column (val_new) in which each value is multiplied by a value in another column (val2) by row. As I want to do this for several groups I'd prefer using dplyr, but how?



    dat <- data.frame(group = rep(c("A", "B"), each = 3),
    val1 = c(50, NA, NA, 40, NA, NA),
    val2 = c(NA, 0.5, 0.3, NA, 0.8, 0.7))

    > dat
    group val1 val2
    1 A 50 NA
    2 A NA 0.5
    3 A NA 0.3
    4 B 40 NA
    5 B NA 0.8
    6 B NA 0.7

    dat %>%
    group_by(group) %>%
    mutate(val_new = ifelse(!is.na(val1), val1, lag(val_new) * val2))

    Error in mutate_impl(.data, dots) :
    Evaluation error: object 'val_new' not found.


    Desired result:



    # A tibble: 6 x 4
    # Groups: group [2]
    group val1 val2 val_new
    <fct> <dbl> <dbl> <dbl>
    1 A 50 NA 50
    2 A NA 0.5 25
    3 A NA 0.3 7.5
    4 B 40 NA 40
    5 B NA 0.8 32
    6 B NA 0.7 22.4









    share|improve this question

























      0












      0








      0








      I'd like to create a new column (val_new) in which each value is multiplied by a value in another column (val2) by row. As I want to do this for several groups I'd prefer using dplyr, but how?



      dat <- data.frame(group = rep(c("A", "B"), each = 3),
      val1 = c(50, NA, NA, 40, NA, NA),
      val2 = c(NA, 0.5, 0.3, NA, 0.8, 0.7))

      > dat
      group val1 val2
      1 A 50 NA
      2 A NA 0.5
      3 A NA 0.3
      4 B 40 NA
      5 B NA 0.8
      6 B NA 0.7

      dat %>%
      group_by(group) %>%
      mutate(val_new = ifelse(!is.na(val1), val1, lag(val_new) * val2))

      Error in mutate_impl(.data, dots) :
      Evaluation error: object 'val_new' not found.


      Desired result:



      # A tibble: 6 x 4
      # Groups: group [2]
      group val1 val2 val_new
      <fct> <dbl> <dbl> <dbl>
      1 A 50 NA 50
      2 A NA 0.5 25
      3 A NA 0.3 7.5
      4 B 40 NA 40
      5 B NA 0.8 32
      6 B NA 0.7 22.4









      share|improve this question














      I'd like to create a new column (val_new) in which each value is multiplied by a value in another column (val2) by row. As I want to do this for several groups I'd prefer using dplyr, but how?



      dat <- data.frame(group = rep(c("A", "B"), each = 3),
      val1 = c(50, NA, NA, 40, NA, NA),
      val2 = c(NA, 0.5, 0.3, NA, 0.8, 0.7))

      > dat
      group val1 val2
      1 A 50 NA
      2 A NA 0.5
      3 A NA 0.3
      4 B 40 NA
      5 B NA 0.8
      6 B NA 0.7

      dat %>%
      group_by(group) %>%
      mutate(val_new = ifelse(!is.na(val1), val1, lag(val_new) * val2))

      Error in mutate_impl(.data, dots) :
      Evaluation error: object 'val_new' not found.


      Desired result:



      # A tibble: 6 x 4
      # Groups: group [2]
      group val1 val2 val_new
      <fct> <dbl> <dbl> <dbl>
      1 A 50 NA 50
      2 A NA 0.5 25
      3 A NA 0.3 7.5
      4 B 40 NA 40
      5 B NA 0.8 32
      6 B NA 0.7 22.4






      r dplyr






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 23 '18 at 10:10









      beetrootbeetroot

      6,63473060




      6,63473060
























          1 Answer
          1






          active

          oldest

          votes


















          2














          Try this:



          dat %>% 
          group_by(group) %>%
          mutate(val_new = cumprod(c(first(val1),val2[-1])))
          ## A tibble: 6 x 4
          ## Groups: group [2]
          # group val1 val2 val_new
          # <fct> <dbl> <dbl> <dbl>
          #1 A 50 NA 50
          #2 A NA 0.5 25
          #3 A NA 0.3 7.5
          #4 B 40 NA 40
          #5 B NA 0.8 32
          #6 B NA 0.7 22.4





          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%2f53444632%2fcalculate-new-values-by-row%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            2














            Try this:



            dat %>% 
            group_by(group) %>%
            mutate(val_new = cumprod(c(first(val1),val2[-1])))
            ## A tibble: 6 x 4
            ## Groups: group [2]
            # group val1 val2 val_new
            # <fct> <dbl> <dbl> <dbl>
            #1 A 50 NA 50
            #2 A NA 0.5 25
            #3 A NA 0.3 7.5
            #4 B 40 NA 40
            #5 B NA 0.8 32
            #6 B NA 0.7 22.4





            share|improve this answer




























              2














              Try this:



              dat %>% 
              group_by(group) %>%
              mutate(val_new = cumprod(c(first(val1),val2[-1])))
              ## A tibble: 6 x 4
              ## Groups: group [2]
              # group val1 val2 val_new
              # <fct> <dbl> <dbl> <dbl>
              #1 A 50 NA 50
              #2 A NA 0.5 25
              #3 A NA 0.3 7.5
              #4 B 40 NA 40
              #5 B NA 0.8 32
              #6 B NA 0.7 22.4





              share|improve this answer


























                2












                2








                2







                Try this:



                dat %>% 
                group_by(group) %>%
                mutate(val_new = cumprod(c(first(val1),val2[-1])))
                ## A tibble: 6 x 4
                ## Groups: group [2]
                # group val1 val2 val_new
                # <fct> <dbl> <dbl> <dbl>
                #1 A 50 NA 50
                #2 A NA 0.5 25
                #3 A NA 0.3 7.5
                #4 B 40 NA 40
                #5 B NA 0.8 32
                #6 B NA 0.7 22.4





                share|improve this answer













                Try this:



                dat %>% 
                group_by(group) %>%
                mutate(val_new = cumprod(c(first(val1),val2[-1])))
                ## A tibble: 6 x 4
                ## Groups: group [2]
                # group val1 val2 val_new
                # <fct> <dbl> <dbl> <dbl>
                #1 A 50 NA 50
                #2 A NA 0.5 25
                #3 A NA 0.3 7.5
                #4 B 40 NA 40
                #5 B NA 0.8 32
                #6 B NA 0.7 22.4






                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 23 '18 at 10:47









                nicolanicola

                18.6k21836




                18.6k21836






























                    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%2f53444632%2fcalculate-new-values-by-row%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







                    Popular posts from this blog

                    Berounka

                    Sphinx de Gizeh

                    Different font size/position of beamer's navigation symbols template's content depending on regular/plain...