hi:
I have a datatable with two columns (see below) and I want to create
another column that adds the values of the rows in the first two
columns. I am trying this:
DT[ , col3 :=rowSums(.SD, na.rm = TRUE), .SDcols = c(col1,col2)]
but I get this error:
Error in inherits(x, data.frame) :
On Thursday 30 May 2013 02:57:04 Camilo Mora wrote:
do you know why is this? or is there another way to sum by row in a
given number of columns?
Without data.table:
x - structure(list(col1 = c(NA, 0, -0.015038, 0.003817, -0.011407
), col2 = c(0.003745, 0.007463, -0.007407, -0.003731,
Hi
I am trying to calculate the row sums of a matrix i have created
The matrix ( FeaturePresenceMatrix) has been created by
1) Read csv
2) Removing unnecesarry data using [-1:4,] command
3) replacing all the NA values with as.numeric(0) and all others with
as.numeric
(1)
When I carry out the
Amit Patel wrote:
Hi
I am trying to calculate the row sums of a matrix i have created
The matrix ( FeaturePresenceMatrix) has been created by
1) Read csv
2) Removing unnecesarry data using [-1:4,] command
3) replacing all the NA values with as.numeric(0) and all others with as.numeric
(1)
Yes, please do as Erik said in the future but here's one way to do it.
(A - matrix(data = rnorm(n = 9, mean = 0, sd = 1), nrow = 3, ncol = 3, byrow =
FALSE, dimnames = NULL))
matrix(rowSums(A))
On Aug 12, 2010, at 11:28 AM, Amit Patel wrote:
Hi
I am trying to calculate the row sums of a
Another suggestion: compare
-1:4
with
-(1:4)
-Peter Ehlers
On 2010-08-12 12:28, Amit Patel wrote:
Hi
I am trying to calculate the row sums of a matrix i have created
The matrix ( FeaturePresenceMatrix) has been created by
1) Read csv
2) Removing unnecesarry data using [-1:4,] command
6 matches
Mail list logo
