Extract or replace parts of three-velocity
Extract or replace subsets of three-velocities
x |
A three-vector |
index |
elements to extract or replace |
value |
replacement value |
These methods (should) work as expected: an object of class
3vel is a three-column matrix with rows corresponding to
three-velocities; a single argument is interpreted as a row number.
Salient use-cases are u[1:5] <- u[1] and u[1] <- 0.
To extract a single component, pass a second index: u[,1]
returns the x- component of the three-velocity.
Extraction functions take a drop argument, except for x[i]
which returns a vec object.
Currently, u[] returns u but I am not sure this is
desirable. Maybe it should return unclass(u) or perhaps
c(unclass(u)).
Use idiom u[] <- x to replace entries of u elementwise.
u <- r3vel(10) u[1:4] u[5:6] <- 0 u[7:8] <- u[1] u[,1] <- 0.1
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.