Question

I am writing a program and trying to break up data, which is stored in an array, in order to make it run faster.
I am attempting to go about it this way:

    data_to_analyze=(1 2 3 4 5 6 7 8 9 10)
    #original array size
    dataSize=(${#data_to_analyze[@]})

    #half of that size
    let samSmall="$dataSize/2"

    #the other half
    let samSmall2=("$dataSize - $samSmall -1")

    #the first half
    smallArray=("${data_to_analyze[@]:0:$samSmall}")

    #the rest
    smallArray2=("${data_to_analyze[@]:$samSmall:$samSmall2}")

    #an array of names(which correspond to arrays)
    combArray=(smallArray smallArray2)
    sizeComb=(${#combArray[@]})

    #for the length of the new array
    for ((i=0; i<= $sizeComb ; i++)); do
        #through first set of data and then loop back around for the second arrays data? 
        for sample_name in ${combArray[i]}; do
            command
            wait
            command
            wait
        done

What I imagine this does is gives only the first array of data to the for loop at first. When the first array is done it should go through again with the second array set.

That leaves me with two questions. Is combArray really passing the two smaller arrays? And is there a better way?

Answer 1

#!/bin/bash
data_to_analyze=(1 2 3 4 5 6 7 8 9 10)
dataSize=${#data_to_analyze[@]}
((samSmall=dataSize/2,samSmall2=dataSize-samSmall))
smallArray=("${data_to_analyze[@]:0:$samSmall}")
smallArray2=("${data_to_analyze[@]:$samSmall:$samSmall2}")
combArray=(smallArray smallArray2)
sizeComb=${#combArray[@]}
for ((i=0;i<$sizeComb;i++));do
    eval 'a=("${'${combArray[i]}'[@]}")'
    for sample_name in "${a[@]}";do
        ...
    done 
done

EDIT: removed the double quotes near ${combArray[i]} and replaced <= by < in for