CODEWITHSUNDEEP
r
rado
rado

Reputation: 399

A cross table in R

I have a data frame like this one:

   v1   v2  wght
1  3    5   0.2
2  2    8   0.5
3  3    5   0.6
................

So I want to produce some descriptive statistics for multiple variables, a cross table more precisely. The values of v1 and v2 are all integers between 1 and 10 and wght is a weight variable. The desired result should be a data frame like this one for example:

        v2_1 ... v2_5 ... v2_8 ...   v2_10
v1_1
v1_2                       0.5
v1_3         0.8=0.2+0.6
...
v1_10

where in each cell you have the number of people who are v2_i amongst those who have v1_j for i and j in [1:10]. These data should be weighted by wght. I tried using Crosstable but the results are impossible to be used afterwards because I need a data frame. Thanks in advance

Upvotes: 1

Views: 832

Answers (1)

akrun
akrun

Reputation: 887901

Try

library(reshape2)
df1[1:2] <- lapply(df1[1:2], function(x) factor(x, levels=1:10))
res1 <- as.data.frame(acast(df1, v1 ~v2 , value.var='wght',
                         fill=0, drop=FALSE, sum))

Or

as.data.frame.matrix(xtabs(wght~v1+v2, df1))

data

set.seed(24)
df1 <- data.frame(v1= sample(1:10, 20, replace=TRUE), 
      v2= sample(1:10, 20, replace=TRUE), wght=rnorm(20))

Upvotes: 3

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