So, I used dcast() on a dataframe last time in which one column was ID and the other multiple codes assigned per id. My df1 looked like this:
ID codes gfreq
123 FGV34 0.988
123 FGV34 0.988
123 FGV34 0.988
566 WER45 na
566 FGV34 0.988
566 FGV34 0.988
in order to manipulate the above format into :
ID FGV34 WER45
123 1 0
566 1 1
dcast(df1, ID ~ codes)
And it had worked perfectly. Now, i have a similar dataframe df2, which has just TWO columns, ID and codes.
ID codes
123 FGV34
123 FGV34
123 FGV34
566 WER45
566 FGV34
566 FGV34
When I run it into dcast: 1. I get a warning about Value.var being overridden and codes column is used as value.var which is okay 2. The format in which I am getting the output is completely different this time.
ID FGV34 WER45
123 FGV34 NA
566 FGV34 WER45
I have checked the datatypes of the attributes in df1 and df2. They are the same for both ID and codes. I want help in getting the output like before with either 0 or 1 instead of NA and column name. Secondly, I want to understand what changed for the dcast() to be behaving differently.
Both reshape2 and spread have been deprecated or retired - the tidyverse now wants you to use pivot_wider. I'm not up to date on that syntax, but dcast still does what you want it to with data.table.
library(data.table)
d1 <- data.table(ID = c(11,11,11,12,12,12),
codes = c('a', 'a', 'a', 'b', 'a', 'a'),
gfreq = c(.5,.5,.5,NA,.5,.5))
dcast(d1, ID ~ codes)
#> Using 'gfreq' as value column. Use 'value.var' to override
#> Aggregate function missing, defaulting to 'length'
#> ID a b
#> 1: 11 3 0
#> 2: 12 2 1
d2 <- data.table(ID = c(11,11,11,12,12,12),
codes = c('a', 'a', 'a', 'b', 'a', 'a'))
dcast(d2, ID ~ codes)
#> Using 'codes' as value column. Use 'value.var' to override
#> Aggregate function missing, defaulting to 'length'
#> ID a b
#> 1: 11 3 0
#> 2: 12 2 1
## If you only want 1's and 0's
dcast(unique(d2), ID ~ codes,
fun.aggregate = length)
#> Using 'codes' as value column. Use 'value.var' to override
#> ID a b
#> 1: 11 1 0
#> 2: 12 1 1
Created on 2019-10-16 by the reprex package (v0.3.0)