I have a data frame df1 and a data frame df 2
df1
colA colB ...
30 2 ...
3 100 ...
15 9 ...
.. .. ...
df2
colA colB ...
10 200 ...
0 10 ...
55 1 ...
.. .. ...
I would like to sum all the rows in colA of df1 with colA in df2 and so on for the rest of the columns
Output:
df3
colA colB
40 202
3 110
70 10
I would like to fill up the values to a matrix I have written something like this:
results <- matrix(NA, ncol=ncol(df1), nrow=nrow(df1))
rownames(results) <- rownames(df1)
colnames(results) <- colnames(df1)
for (i in seq(df1)) {
tempCol1 <- df1[, i]
for (row in rownames(results))
for (j in seq(results)){
results[row,j]<-sum(df1[row, tempCol1 ],
df2[row, tempCol1 ])
}}
it give this error:
Error in
[<-
(*tmp*
, row, j, value = sum(a[row, tempCol1], b[row, tempCol1])) : subscript out of bounds
CodePudding user response:
Make it to a matrix and add up them.
Directly add two data.frame
also works as well.
df1 = data.frame(colA = c(30, 3, 15), colB = c(2, 100, 9))
df2 = data.frame(colA = c(10, 0, 55), colB = c(200, 10, 1))
as.matrix(df1) as.matrix(df2)
df1 df2
> as.matrix(df1) as.matrix(df2)
colA colB
[1,] 40 202
[2,] 3 110
[3,] 70 10
> df1 df2
colA colB
1 40 202
2 3 110
3 70 10
CodePudding user response:
You do not have to use a for loop
for this problem. Simply add them up:
m = as.matrix(df1 df2)
CodePudding user response:
We can do a regular which will preserve the matrix format and does the elementwise summation, below snippet will get the job done
df1 <- data.frame (
col1 = c(30, 3, 15),
col2 = c(2, 100, 19)
)
df2 <- data.frame (
col1 = c(30, 3, 15),
col2 = c(2, 100, 19)
)
my_mat1 <- as.matrix(df1)
my_mat2 <- as.matrix(df2)
result = my_mat1 my_mat2;