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Finding Max value from an array


 
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# 8  
Old 08-02-2009
Thanks for the replies.

But now i have modified my script from an array to a file. Now I will have to find the Max and Second Max from a file and store them in two variables.

Also

---------- Post updated at 09:39 AM ---------- Previous update was at 09:14 AM ----------

[/COLOR]
Quote:
Originally Posted by matrixmadhan
Thanks for posting what you have tried Smilie

One more variable and keep flipping - but not efficient

Code:
awk 'BEGIN{ max = -1; second_max = -1 }{ if ( $0 > max ) { second_max = max; max = $0 } }END{ print second_max }' file

This is failing in the case the contents of file are:
0336
0405
0337
0338

max is 0405 and second max is 0338.. but above code is returning 0336 as second max..

Last edited by vjasai; 08-02-2009 at 11:37 AM..
# 9  
Old 08-02-2009
Here is solution for you, little fix your 1st script. No need to echo array, use it. You can test values or give the list for sort and then take so many value as you like.
Code:
#!/bin/ksh
#!/bin/bash

array=(0338 0337 0339 0340 0401 0402 0403)
for i in ${array[*]}
do
        echo "$i"
done | sort -nr | head -2

Or you can put sorted list to the array and take so many values as you like:
Code:
# set array using array=( list of values )
# make max
max=(
$(for i in ${array[*]}
do
        echo "$i"
done | sort -nr ) 
)
echo "1st: ${max[0]}" 
echo "2nd: ${max[1]}"
echo "3th: ${max[2]}"



---------- Post updated at 08:56 PM ---------- Previous update was at 08:32 PM ----------

Using file:
Code:
array=( $(<somefile ) )

max=(
$(for i in ${array[*]}
do
        echo "$i"
done | sort -nr )
)
echo "1. ${max[0]}"
echo "2. ${max[1]}"

Or using sort and two first lines:
Code:
cnt=1
sort -nr somefile | while read line
do
        (( cnt  > 2 )) && break
        echo "$cnt. $line"
        (( cnt+=1))
done

Or ...

---------- Post updated at 09:00 PM ---------- Previous update was at 08:56 PM ----------

Using sort + awk
Code:
sort -nr somefile | awk 'NR <= 2 { print NR ".",$1 }'

# 10  
Old 08-03-2009
Quote:
Originally Posted by vjasai
Thanks for the replies.

But now i have modified my script from an array to a file. Now I will have to find the Max and Second Max from a file and store them in two variables.

Also

---------- Post updated at 09:39 AM ---------- Previous update was at 09:14 AM ----------

[/COLOR]

This is failing in the case the contents of file are:
0336
0405
0337
0338

max is 0405 and second max is 0338.. but above code is returning 0336 as second max..
That's a good catch Smilie

Code:
awk 'BEGIN{ max = -1; second_max = -1 }{ if ( $0 > max ) { second_max = max; max = $0 } else { if ( $0 > second_max ) second_max = $0 } }END{ print second_max }' filename

# 11  
Old 08-03-2009
Quote:
Originally Posted by scottn
Leading 0's will take care of that...
Was not sure if its always going to be 4 char long

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