CODEWITHSUNDEEP
r
safc
safc

Reputation: 13

Reformatting a list in R

I have a list of my results in R in the format:

Result:
Cat1
Cat2
Cat1
Cat3
...

I need to get it into the format:

Results:
        ....Cat 1.....Cat 2.....Cat3
            1         0         0
            0         1         0
            1         0         0
            0         0         1

I know this is a basic question, but without knowing the terms to search for I am having a very difficult time finding an answer. Thank you very much for your time.

Upvotes: 1

Views: 39

Answers (1)

akrun
akrun

Reputation: 887891

I guess you need model.matrix

model.matrix(~0+Category, df1)
#  CategoryCat1 CategoryCat2 CategoryCat3
#1            1            0            0
#2            0            1            0
#3            1            0            0
#4            0            0            1
#attr(,"assign")
#[1] 1 1 1
#attr(,"contrasts")
#attr(,"contrasts")$Category
#[1] "contr.treatment"

Or use table

table(1:nrow(df1), df1$Category)

#     Cat1 Cat2 Cat3
#  1    1    0    0
#  2    0    1    0
#  3    1    0    0
#  4    0    0    1

data

df1 <- structure(list(Category = c("Cat1", "Cat2", "Cat1", "Cat3")),
.Names = "Category", class = "data.frame", row.names = c(NA, -4L))

Upvotes: 1

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