Description Usage Arguments Value Author(s) See Also Examples
Within bolts in a RStorm stream the TrackRow
function can be used to store the state of variables at that point during the stream. The TrackRow
function will store values incrementally during the stream. Thus, TrackRow
enables one to store a set of parameter at each event in a Bolt.
1 |
name |
a string with the name of the object that is stored. |
row |
a single row data.frame containing the parameters that are supposed to be tracked over time. See example. |
TRUE if the row is correctly stored.
Maurits Kaptein
Topology
, GetTrack
, GetTrackNames
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | # Create a topology with a simple spout
topology <- Topology(data.frame(x=c(1:10)))
# Define the bolt and add it
computeSum <- function(x, ...){
sum <- GetHash("sum")
if(is.data.frame(sum)){
x <- sum + (x[1])
}
SetHash("sum", x)
TrackRow("sum", data.frame(x=x))
}
topology <- AddBolt(topology, Bolt(computeSum))
# Run the stream
result <- RStorm(topology)
# Insepct the result over the timepoints in the stream
GetTrack("sum", result)
|
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