Combine values in two columns together based specific conditions in R - r

I have data that looks like the following:
moo <- data.frame(Farm = c("A","B",NA,NA,"A","B"),
Barn_Yard = c("A","A",NA,"A",NA,"B"),
stringsAsFactors=FALSE)
print(moo)
Farm Barn_Yard
A A
B A
<NA> <NA>
<NA> A
A <NA>
B B
I am attempting to combine the columns into one variable where if they are the same the results yields what is found in both columns, if both have data the result is what is in the Farm column, if both are <NA> the result is <NA>, and if one has a value and the other doesn't the result is the value present in the column that has the value. Thus, in this instance the result would be:
oink <- data.frame(Animal_House = c("A","B",NA,"A","A","B"),
stringsAsFactors = FALSE)
print(oink)
Animal_House
A
B
<NA>
A
A
B
I have tried the unite function from tidyr but it doesn't give me exactly what I want. Any thoughts? Thanks!

dplyr::coalesce does exactly that, substituting any NA values in the first vector with the value from the second:
library(dplyr)
moo <- data.frame(Farm = c("A","B",NA,NA,"A","B"),
Barn_Yard = c("A","A",NA,"A",NA,"B"),
stringsAsFactors = FALSE)
oink <- moo %>% mutate(Animal_House = coalesce(Farm, Barn_Yard))
oink
#> Farm Barn_Yard Animal_House
#> 1 A A A
#> 2 B A B
#> 3 <NA> <NA> <NA>
#> 4 <NA> A A
#> 5 A <NA> A
#> 6 B B B
If you want to discard the original columns, use transmute instead of mutate.

A less succinct option is to use a couple ifelse() statements, but this could be useful if you wish to introduce another condition or column into the mix.
moo <- data.frame(Farm = c("A","B",NA,NA,"A","B"),
Barn_Yard = c("A","A",NA,"A",NA,"B"),
stringsAsFactors = FALSE)
moo$Animal_House = with(moo,ifelse(is.na(Farm) & is.na(Barn_Yard),NA,
ifelse(!is.na(Barn_Yard) & is.na(Farm),Barn_Yard,
Farm)))

Related

How to Insert rows into a single column in an empty dataframe in R?

I have the following empty dataframe/tibble:
new_table <- tibble(
country = character(),
code = character()
)
Which is empty after creating it 0 rows x 2 columns
And i have the following data frame of codes:
df_codes <- tibble(codes = c('CH','US','UK'))
which looks like this:
codes
-----
CH
US
UK
Is there way of looping through each element in the df_codes dataframe and inserting these values into my new_table dataframes code column?
I have tried the following code but to no avail:
for(c in unique(df_codes$codes)){
new_table <- new_table %>% mutate(code = c)
return(new_table)
}
But this returns still a dataframe with 0 rows and 2 columns:
Ideally i would like this output when calling new_table:
country|code
-------|-----
NA | CH
NA | US
NA | UK
Any help is appreciated
We can just use bind_rows
library(dplyr)
bind_rows(new_table, df_codes)
-output
# A tibble: 3 x 2
# country code
# <chr> <chr>
#1 <NA> CH
#2 <NA> US
#3 <NA> UK
Or instead of using bind_rows, this can be done with base R by doing an assignment
new_table[seq_len(nrow(df_codes)), names(df_codes)] <- df_codes
where
df_codes <- tibble(code = c('CH','US','UK'))
Another base R option is merge
merge(new_table,df_codes, by.x = "code", by.y = "codes",all = TRUE)
which gives
code country
1 CH <NA>
2 UK <NA>
3 US <NA>

How to keep one instance or more of the values in one column when removing duplicate rows?

I'm trying to remove rows with duplicate values in one column of a data frame. I want to make sure that all the existing values in that column are represented, appearing more than once if its values in one other column are not duplicated and non-missing, and only once if the values in that other column are all missing. Take for example the following data frame:
toy <- data.frame(Group = c(1,1,2,2,2,3,3,4,5,5,6,7,7), Class = c("a",NA,"a","b",NA,NA,NA,NA,"a","b","a","a","a"))
I would like to end up with this:
ideal <- data.frame(Group = c(1,2,2,3,4,5,5,6,7), Class = c("a","a","b",NA,NA,"a","b","a","a"))
I tried transforming the data frame into a data table and follow the advice here, like this:
library(data.table)
toy.dt <- as.data.table(toy)
toy.dt[, .(Class = if(all(is.na(Class))) NA_character_ else na.omit(Class)), by = Group]
but duplicates weren't handled as needed: value 7 in the column 'Group' should appear only once in the resulting data.
It would be a bonus if the solution doesn't require transforming the data into a data table.
Here is one way using base R. We first drop NA rows in toy and select only unique rows. We can then left join it with unique Group values to get the rows which are NA for the group.
df1 <- unique(na.omit(toy))
merge(unique(subset(toy, select = Group)), df1, all.x = TRUE)
# Group Class
#1 1 a
#2 2 a
#3 2 b
#4 3 <NA>
#5 4 <NA>
#6 5 a
#7 5 b
#8 6 a
#9 7 a
Same logic using dplyr functions :
library(dplyr)
toy %>%
na.omit() %>%
distinct() %>%
right_join(toy %>% distinct(Group))
If you would like to try a tidyverse approach:
library(tidyverse)
toy %>%
group_by(Group) %>%
filter(!(is.na(Class) & sum(!is.na(Class)) > 0)) %>%
distinct()
Output
# A tibble: 9 x 2
# Groups: Group [7]
Group Class
<dbl> <chr>
1 1 a
2 2 a
3 2 b
4 3 NA
5 4 NA
6 5 a
7 5 b
8 6 a
9 7 a

separte columns from a data frame

I have a data frame results from extracting data from text files which have some columns which contains more than a value
I want to split columns with more than a value into 2 columns like this
I tried this code but it generates an error
db<-separate_rows(db,TYPE,CHRO,EX ,sep=",\\s+")
Error: All nested columns must have the same number of elements.
Note that sample data and expected output don't match; for example, there is no CHRO=c700 entry in your sample data. You also seem to be missing rows. Please check your input/expected output data.
You could use tidyr::separate_rows, e.g.
df %>%
separate_rows(TYPE, sep = ",") %>%
separate_rows(CHRO, sep = ",") %>%
separate_rows(EX, sep = ",")
# TYPE CHRO EX
#1 multiple c.211dup <NA>
#2 multiple c.3751dup <NA>
#3 multiple <NA> exon.2
#4 multiple <NA> exon.3
#5 multiple <NA> exon.7
#6 mitocondrial <NA> exon.3
#7 mitocondrial <NA> exon.7
#8 multifactorial <NA> <NA>
Or perhaps use splitstackshape
library(splitstackshape)
df %>%
cSplit(names(df), direction = "long") %>%
fill(TYPE) %>%
group_by_at(names(df)) %>%
slice(1)
# TYPE CHRO EX
# <fct> <fct> <fct>
#1 mitocondrial NA exon.7
#2 multifactorial NA NA
#3 multiple c.211dup NA
#4 multiple c.3751dup NA
#5 multiple NA exon.2
#6 multiple NA exon.3
#7 multiple NA NA
Note that results are different because the order of separating columns matters.
Sample data
df <- read.table(text =
"TYPE CHRO EX
multiple 'c.211dup, c.3751dup' NA
multiple NA exon.2
multiple,mitocondrial NA exon.3,exon.7
multifactorial NA NA", header = T)

R: Cleaning up a wide and untidy dataframe

I have a data frame that looks like:
d<-data.frame(id=(1:9),
grp_id=(c(rep(1,3), rep(2,3), rep(3,3))),
a=rep(NA, 9),
b=c("No", rep(NA, 3), "Yes", rep(NA, 4)),
c=c(rep(NA,2), "No", rep(NA,6)),
d=c(rep(NA,3), "Yes", rep(NA,2), "No", rep(NA,2)),
e=c(rep(NA, 7), "No", NA),
f=c(NA, "No", rep(NA,3), "No", rep(NA,2), "No"))
>d
id grp_id a b c d e f
1 1 1 NA No <NA> <NA> <NA> <NA>
2 2 1 NA <NA> <NA> <NA> <NA> No
3 3 1 NA <NA> No <NA> <NA> <NA>
4 4 2 NA <NA> <NA> Yes <NA> <NA>
5 5 2 NA Yes <NA> <NA> <NA> <NA>
6 6 2 NA <NA> <NA> <NA> <NA> No
7 7 3 NA <NA> <NA> No <NA> <NA>
8 8 3 NA <NA> <NA> <NA> No <NA>
9 9 3 NA <NA> <NA> <NA> <NA> No
Within each group (grp_id) there is only 1 "Yes" or "No" value associated with each of the columns a:f.
I'd like to create a single row for each grp_id to get a data frame that looks like the following:
grp_id a b c d e f
1 NA No No <NA> <NA> No
2 NA Yes <NA> Yes <NA> No
3 NA <NA> <NA> No No No
I recognize that the tidyr package is probably the best tool and the 1st steps are likely to be
d %>%
group_by(grp_id) %>%
summarise()
I would appreciate help with the commands within summarise, or any solution really. Thanks.
We can use summarise_at and subset the first non-NA element
library(dplyr)
d %>%
group_by(grp_id) %>%
summarise_at(2:7, funs(.[!is.na(.)][1]))
# A tibble: 3 x 7
# grp_id a b c d e f
# <dbl> <lgl> <fctr> <fctr> <fctr> <fctr> <fctr>
#1 1 NA No No <NA> <NA> No
#2 2 NA Yes <NA> Yes <NA> No
#3 3 NA <NA> <NA> No No No
In the example dataset, columns 'a' to 'f' are all factors with some having only 'No' levels. If it needs to be standardized with all the columns having the same levels, then we may need to call the factor with levels specified as c('Yes', 'No') in the summarise_at i.e. summarise_at(2:7, funs(factor(.[!is.na(.)][1], levels = c('Yes', 'No'))))
We can use aggregate. No packages are used.
YN <- function(x) c(na.omit(as.character(x)), NA)[1]
aggregate(d[3:8], d["grp_id"], YN)
giving:
## grp_id a b c d e f
## 1 1 <NA> No No <NA> <NA> No
## 2 2 <NA> Yes <NA> Yes <NA> No
## 3 3 <NA> <NA> <NA> No No No
The above gives character columns. If you prefer factor columns then use this:
YNfac <- function(x) factor(YN(x), c("No", "Yes"))
aggregate(d[3:8], d["grp_id"], YNfac)
Note: Other alternate implementations of YN are:
YN <- function(x) sort(as.character(x), na.last = TRUE)[1]
YN <- function(x) if (all(is.na(x))) NA_character_ else na.omit(as.character(x))[1]
library(zoo)
YN <- function(x) na.locf0(as.character(x), fromLast = TRUE)[1]
You've received some good answers but neither of them actually uses the tidyr package. (The summarize() and summarize_at() family of functions is from dplyr.)
In fact, a tidyr-only solution for your problem is very doable.
d %>%
gather(col, value, -id, -grp_id, factor_key=TRUE) %>%
na.omit() %>%
select(-id) %>%
spread(col, value, fill=NA, drop=FALSE)
The only hard part is ensuring that you get the a column in your output. For your example data, it is entirely NA. The trick is the factor_key=TRUE argument to gather() and the drop=FALSE argument to spread(). Without those two arguments being set, the output would not have an a column, and would only have columns with at least one non-NA entry.
Here's a description of how it works:
gather(col, value, -id, -grp_id, factor_key=TRUE) %>%
This tidies your data -- it effectively replaces columns a - f with new columns col and value, forming a long-formated "tidy" data frame. The entries in the col column are letters a - f. And because we've used factor_key=TRUE, this column is a factor with levels, not just a character vector.
na.omit() %>%
This removes all the NA values from the long data.
select(-id) %>%
This eliminates the id column.
spread(col, value, fill=NA, drop=FALSE)
This re-widens the data, using the values in the col column to define new column names, and the values in the value column to fill in the entries of the new columns. When data is missing, a value of fill (here NA) is used instead. And the drop=FALSE means that when col is a factor, there will be one column per level of the factor, no matter whether that level appears in the data or not. This, along with setting col to be a factor, is what gets a as an output column.
I personally find this approach more readable than the approaches requiring subsetting or lapply stuff. Additionally, this approach will fail if your data is not actually one-hot, whereas other approaches may "work" and give you unexpected output. The downside of this approach is that the output columns a - f are not factors, but character vectors. If you need factor output you should be able to do (untested)
mutate(value = factor(value, levels=c('Yes', 'No', NA))) %>%
anywhere between the gather() and spread() functions to ensure factor output.

r matrix columns filling incorrectly

Trying to re-organise a data set (sdevDFC) into a matrix with my latitude (Lat) as row names and longitude (Lon) as column names, then filling in the matrix with values respective to the coordinates.
stand_dev_m <- matrix(data=sdevDFC$SDev, nrow=length(sdevDFC$Lat), ncol=length(sdevDFC$Lon), byrow=TRUE, dimnames = list(sdevDFC$Lat, sdevDFC$Lon))
The column and row names appear as they should, but my data fills in so that all values in their respective columns are identical as shown in the
image (which should not be the case as none of my values ever repeat).
I've filled it with byrow = FALSE to see if it also occurred then (it does), and I've also used colnames and rownames instead of dimnames (changes nothing).
Would appreciate any insight into what I may be doing wrong here--also new to this platform so I apologise if I've missed a guideline or another question that's similar
Example data:
df <- data.frame(LON=1:5,
LAT=11:15,
VAL=letters[1:5],
stringsAsFactors=F)
You could try the following:
rn <- df$LON # Save what-will-be-rownames
df1 <- df %>%
spread(LAT,VAL,fill=NA) %>%
select(-LON) %>%
setNames(., df$LAT)
rownames(df1) <- rn
Output
11 12 13 14 15
1 a <NA> <NA> <NA> <NA>
2 <NA> b <NA> <NA> <NA>
3 <NA> <NA> c <NA> <NA>
4 <NA> <NA> <NA> d <NA>
5 <NA> <NA> <NA> <NA> e

Resources