CODEWITHSUNDEEP
rlistloopsformatting
Ladislav Naďo
Ladislav Naďo

Reputation: 862

Create list of tables by loop in R

I am struggling to create list of tables (object = table, not data.frame) by loop in R. Structure of my data is also a little bit complicated - sometimes the table function do not give 2x2 table - how to fill tables with incomplete dimensions to 2x2 automatically?

Sample data (in real dataset much much larger...)

my.data <- data.frame(y.var = c(0,1,0,1,1,1,0,1,1,0),
                      sex = rep(c("male","female"), times = 5),
                      apple = c(0,1,1,0,0,0,1,0,0,0),
                      orange = c(1,0,1,1,0,1,1,1,0,0),
                      ananas = c(0,0,0,0,0,0,0,0,0,0))


#    y.var    sex apple orange ananas
# 1      0   male     0      1      0
# 2      1 female     1      0      0
# 3      0   male     1      1      1

Look into creating tables - for apple I have nice 2x2 tables

table(my.data$y.var, my.data$apple)
#     0 1
#   0 2 2
#   1 5 1        .... Ok, nice 2x2 table.
table(my.data$y.var, my.data$apple, my.data$sex)
# , ,  = female
#     0 1
#   0 1 0
#   1 3 1
# , ,  = male
#     0 1
#   0 1 2
#   1 2 0        .... Ok, nice 2x2 table.

However for ananas I have only 2x1 tables

table(my.data$y.var, my.data$ananas)
#     0                                                 #     0 1
#   0 4                                                 #   0 4 0
#   1 6        .... NOT Ok! I need 2x2 table like this: #   1 6 0
table(my.data$y.var, my.data$ananas, my.data$sex)
# , ,  = female
#     0                                                 #     0 1
#   0 1                                                 #   0 1 0
#   1 4        .... NOT Ok! I need 2x2 table like this: #   1 4 0
# , ,  = male
#     0                                                 #     0 1
#   0 3                                                 #   0 3 0
#   1 2        .... NOT Ok! I need 2x2 table like this: #   1 2 0

I can do list manually like this, however this is not very practical.

my.list <- list(table(my.data$y.var, my.data$apple),
             table(my.data$y.var, my.data$apple, my.data$sex),
             table(my.data$y.var, my.data$orange),
             table(my.data$y.var, my.data$orange, my.data$sex),
             table(my.data$y.var, my.data$ananas),
             table(my.data$y.var, my.data$ananas, my.data$sex))

How to do self-correcting-table-dimensions-loop? Necessary for following analyses...

Upvotes: 2

Views: 1033

Answers (1)

akrun
akrun

Reputation: 886978

We can use lapply to loop over the list of columns after converting the columns of interest to have the same levels with factor and then do a table and keep the output in the list

my.data[-2] <- lapply(my.data[-2], factor, levels = 0:1)
lst1 <- lapply(my.data[3:5], function(x) table(my.data$y.var, x))

Upvotes: 1

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