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, -0.00
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")
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
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 matr
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)
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
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