Hi, This is a mailing list related to the data.table package, not general R help. See https://www.r-project.org/help.html
If you're interested in dplyr, its forum might be a good place to learn: https://community.rstudio.com/t/faq-whats-a-reproducible-example-reprex-and-how-do-i-do-one/5219 Best, Frank On Sat, Mar 3, 2018 at 7:06 PM, bigappleanalyst <[email protected]> wrote: > I have a flat file that I imported into R. The file is 10,000 rows. In the > file there is a date variable, and a group variable. There are 100 groups, > so the group variable shows a value of 1 for rows 1:100, a value of 2 for > rows 101:200, and so on for all 100 groups. The date variable has 100 > unique > entries, and repeats/restarts for each group. Thus, the dates in rows 1:100 > are identical to the dates in rows 101:200, 201:300, and so on. > > I wrote a function that manipulates a vector in the flat file, vector_1. As > it stands, it manipulates vector_1 across all 10,000 rows. Vector_1 has > unique entries in rows 1:100, 101:200, 201:300, and so on. Thus, I would > like to implement a parameter so the function only calculates across the > specified range. If I input group = 1, then the function will only perform > the calculation on vector_1 for rows 1:100. > > Here is my function: > > adjusted <- c() > Adjustment <- function(delta, length) { > adjusted <<- vector_1 + delta*(index <= length) > head(adjusted) > } > > Here is a hard-coded example of what I would like to achieve: > > adjusted <- c() > Adjustment <- function(delta, length, group = 1) { > adjusted <<- vector_1[1:100] + delta*(index <= length) > head(adjusted) > } > > I would like to implement a parameter or a loop that performs the > calculation over the corresponding range of vector_1 for the inputted group > parameter value. For example, if I instead entered group =2 the function > would look like: > > adjusted <- c() > Adjustment <- function(delta, length, group = 2) { > adjusted <<- vector_1[101:200] + delta*(index <= length) > head(adjusted) > } > > How would I achieve this? How do I manipulate the original group, date, and > vector_1 vectors to allow for this modular calculation? > > Finally, I would like the function to store a unique "adjusted" vector for > all 100 groups. For example, adjusted_1, adjusted_2, and so on... > > I found that the dplyr package may be useful for this, but I haven't been > successful in implementing it. > > Any insight would be much appreciated! > > > > -- > Sent from: http://r.789695.n4.nabble.com/datatable-help-f2315188.html > _______________________________________________ > datatable-help mailing list > [email protected] > https://lists.r-forge.r-project.org/cgi-bin/mailman/ > listinfo/datatable-help >
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