product {matrixStats} | R Documentation |
Calculates the product for each row (column) in a matrix.
product(x, idxs = NULL, na.rm = FALSE, ...) rowProds(x, rows = NULL, cols = NULL, na.rm = FALSE, method = c("direct", "expSumLog"), ...) colProds(x, rows = NULL, cols = NULL, na.rm = FALSE, method = c("direct", "expSumLog"), ...)
x |
|
idxs, rows, cols |
A |
na.rm |
If |
... |
Not used. |
method |
A |
If method = "expSumLog"
, then then product
() function is
used, which calculates the produce via the logarithmic transform (treating
negative values specially). This improves the precision and lowers the risk
for numeric overflow. If method = "direct"
, the direct product is
calculated via the prod
() function.
Returns a numeric
vector
of
length N (K).
Note, if method = "expSumLog"
, na.rm = FALSE
, and x
contains missing values (NA
or
NaN
), then the calculated value is also
missing value. Note that it depends on platform whether
NaN
or NA
is returned
when an NaN
exists, cf.
is.nan
().
Henrik Bengtsson