pipeline

I came across several references to the concept of a dual issue processor (I hope this even makes sense in a sentence). I can't find any explanation of what exactly dual issue is. Google gives me links to micro-controller specification, but the concept isn't explained anywhere. Here's an example of such reference . Am I looking in the wrong place? A brief paragraph on what it is would be very helpful. Dual issue means that each clock cycle the processor can move two instructions from one stage of the pipeline to another. Where this happens depends on the processor and the company's terminology

When combining stderr with stdout, why does 2>&1 need to come before a | (pipe) but after a > myfile (redirect to file)? To redirect stderr to stdout for file output: echo > myfile 2>&1 To redirect stderr to stdout for a pipe: echo 2>&1 | less My assumption was that I could just do: echo | less 2>&1 and it would work, but it doesn't. Why not? A pipeline is a |-delimited list of commands . Any redirections you specify apply to the constituent commands (simple or compound), but not to the pipeline as a whole. Each pipe chains one command's stdout to the stdin of the next by implicitly applying a

I'm asking this question because I couldn't figure it out why nlxb fitting function does not work with the predict() function. I have been looking around to solve this but so far no luck:( I use dplyr to group data and use do to fit each group using nlxb from nlmrt package. Here is my attempt set.seed(12345) set =rep(rep(c("1","2","3","4"),each=21),times=1) time=rep(c(10,seq(100,900,100),seq(1000,10000,1000),20000),times=1) value <- replicate(1,c(replicate(4,sort(10^runif(21,-6,-3),decreasing=FALSE)))) data_rep <- data.frame(time, value,set) > head(data_rep) # time value set #1 10 1.007882e-06

With Airflow, is it possible to restart an upstream task if a downstream task fails? This seems to be against the "Acyclic" part of the term DAG. I would think this is a common problem though. Background I'm looking into using Airflow to manage a data processing workflow that has been managed manually. There is a task that will fail if a parameter x is set too high, but increasing the parameter value gives better quality results. We have not found a way to calculate a safe but maximally high parameter x. The process by hand has been to restart the job if failed with a lower parameter until it

I observed a few times now that A | B | C may not lead to immediate output, although A is constantly producing output. I have no idea how this even may be possible. From my understanding all three processes ought to be working on the same time, putting their output into the next pipe (or stdout) and taking from the previous pipe when they are finished with one step. Here's an example where I am currently experiencing that: tcpflow -ec -i any port 8340 | tee second.flow | grep -i "\(</Manufacturer>\)\|\(</SerialNumber>\)" | awk -F'[<>]' '{print $3}' What is supposed to happen: I look at one