How to round a data.frame in R that contains some character variables?

How to round a data.frame in R that contains some character variables?

I have a dataframe, and I wish to round all of the numbers (ready for export). This must be straightforward, but I am having problems because some bits of the dataframe are not numeric numbers. For example I want to round the figures to the nearest whole number in the example below:

ID = c("a","b","c","d","e")  Value1 = c("3.4","6.4","8.7","1.1","0.1")  Value2 = c("8.2","1.7","6.4","1.9","10.3")  df<-data.frame(ID,Value1,Value2)  

Can anyone help me out? I can round individual columns (e.g., round(df$Value1, 2)) but I want to round a whole table which contains some columns which are not numeric.

Answer by Gago-Silva for How to round a data.frame in R that contains some character variables?

Why don't you just use ID as the row name?

... and take out the "'s from value1 and value2 data

Try this instead:

ID = c("a","b","c","d","e")  Value1 = c(3.4,6.4,8.7,1.1,0.1)  Value2 = c(8.2,1.7,6.4,1.9,10.3)    df<-data.frame(ID,Value1,Value2,row.names=TRUE)    > df    Value1 Value2  a    3.4    8.2  b    6.4    1.7  c    8.7    6.4  d    1.1    1.9  e    0.1   10.3    > str(df)  'data.frame':   5 obs. of  2 variables:   $ Value1: num  3.4 6.4 8.7 1.1 0.1   $ Value2: num  8.2 1.7 6.4 1.9 10.3  

I am not sure what you want to do with the round, but you have some options in R:

?ceiling()  ?floor()  ?trunc()  

Answer by P Lapointe for How to round a data.frame in R that contains some character variables?

First make sure your number columns are numeric:

ID = c("a","b","c","d","e")  Value1 = as.numeric(c("3.4","6.4","8.7","1.1","0.1"))  Value2 = as.numeric(c("8.2","1.7","6.4","1.9","10.3"))  df<-data.frame(ID,Value1,Value2, stringsAsFactors = FALSE)  

Then, round only the numeric columns:

df[,-1] <-round(df[,-1],0) #the "-1" excludes column 1  df      ID Value1 Value2  1  a      3      8  2  b      6      2  3  c      9      6  4  d      1      2  5  e      0     10  

Answer by akhmed for How to round a data.frame in R that contains some character variables?

Recognizing that this is an old question and one answer is accepted, I would like to offer another solution since the question appears as a top-ranked result on Google.

A more general solution is to create a separate function that searches for all numerical variables and rounds them to the specified number of digits:

round_df <- function(df, digits) {    nums <- vapply(df, is.numeric, FUN.VALUE = logical(1))      df[,nums] <- round(df[,nums], digits = digits)      (df)  }  

Once defined, you can use it as follows:

> round_df(df, digits=3)  

Answer by Ben for How to round a data.frame in R that contains some character variables?

The other answers do not quite answer the OP's question exactly because they assume the example data is different from what the OP has provided.

If we read the question literally, and we want a general solution that will find columns with digits in them (of any vector type), convert them to numeric, and then perform another numeric operation, such as rounding. We can use purrr:dmap and do it like this:

Here's the data as provided by the OP, where all cols are factors (an annoying default, but we can deal with it):

ID = c("a","b","c","d","e")  Value1 = c("3.4","6.4","8.7","1.1","0.1")  Value2 = c("8.2","1.7","6.4","1.9","10.3")  df<-data.frame(ID,Value1,Value2)    str(df)  'data.frame':   5 obs. of  3 variables:   $ ID    : Factor w/ 5 levels "a","b","c","d",..: 1 2 3 4 5   $ Value1: Factor w/ 5 levels "0.1","1.1","3.4",..: 3 4 5 2 1   $ Value2: Factor w/ 5 levels "1.7","1.9","10.3",..: 5 1 4 2 3  

We'll search for cols with digits in them, and make a dataframe of indices to mark the numerics:

library(dplyr)  library(purrr)    df_logical <-   df %>%     dmap(function(i) grepl("[0-9]", i))    df_logical       ID Value1 Value2  1 FALSE   TRUE   TRUE  2 FALSE   TRUE   TRUE  3 FALSE   TRUE   TRUE  4 FALSE   TRUE   TRUE  5 FALSE   TRUE   TRUE    str(df_logical)  'data.frame':   5 obs. of  3 variables:   $ ID    : logi  FALSE FALSE FALSE FALSE FALSE   $ Value1: logi  TRUE TRUE TRUE TRUE TRUE   $ Value2: logi  TRUE TRUE TRUE TRUE TRUE  

Then we can use these indices to select a subset of the cols in the original dataframe and convert them to numeric, and do other things also (in this case, rounding):

df_numerics <-   map(1:ncol(df), function(i) ifelse(df_logical[,i],                                         as.numeric(as.character(df[,i])),                                         df[,i])) %>%     dmap(round, 0) %>%     setNames(names(df))   

And we've got the desired result:

df_numerics    ID Value1 Value2  1  1      3      8  2  2      6      2  3  3      9      6  4  4      1      2  5  5      0     10    str(df_numerics)  'data.frame':   5 obs. of  3 variables:   $ ID    : num  1 2 3 4 5   $ Value1: num  3 6 9 1 0   $ Value2: num  8 2 6 2 10  

This could be useful in the case of a dataframe with a large number of columns, and where we have many character/factor type cols full of digits that we want as numeric, but it's too tedious to do by hand.

Answer by Alvis for How to round a data.frame in R that contains some character variables?

I know this is a late reply, but I also had this same problem. After doing some searching I found this to be the most elegant solution:

data.frame(lapply(x, function(y) if(is.numeric(y)) round(y, 2) else y))   

Solution originally from: Jean V. Adams Statistician U.S. Geological Survey Great Lakes Science Center 223 East Steinfest Road Antigo, WI 54409 USA

http://r.789695.n4.nabble.com/round-a-data-frame-containing-character-variables-td3732415.html

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