I would like to write a script that will create me an array with the following values:
{0.1 0.2 0.3 ... 2.5}
Until now I was using a script as follows:
plist=(0.1 0.2 0.3 0.4)
for i in ${plist[#]}; do
echo "submit a simulation with this parameter:"
echo "$i"
done
But now I need the list to be much longer ( but still with constant intervals).
Is there a way to create such an array in a single command? what is the most efficient way to create such a list?
Using seq you can say seq FIRST STEP LAST. In your case:
seq 0 0.1 2.5
Then it is a matter of storing these values in an array:
vals=($(seq 0 0.1 2.5))
You can then check the values with:
$ printf "%s\n" "${vals[#]}"
0,0
0,1
0,2
...
2,3
2,4
2,5
Yes, my locale is set to have commas instead of dots for decimals. This can be changed setting LC_NUMERIC="en_US.UTF-8".
By the way, brace expansion also allows to set an increment. The problem is that it has to be an integer:
$ echo {0..15..3}
0 3 6 9 12 15
Bash supports C style For loops:
$ for ((i=1;i<5;i+=1)); do echo "0.${i}" ; done
0.1
0.2
0.3
0.4
Complementing the main answer
In my case, seq was not the best choice.
To produce a sequence, you can also use the jot utility. However, this command has a more elaborated syntaxis.
# 1 2 3 4
jot - 1 4
# 3 evenly distributed numbers between 0 and 10
# 0 5 10
jot 3 0 10
# a b c ... z
jot -c - 97 122
Related
I have a .txt file in which two set of data are in the same column but divided by some characters, here an example:
#First set of data
#Time #Velocity
1 0.3
2 0.5
3 0.8
4 1.3
#Second set of data
#Time #Velocity
1 0.7
2 0.9
3 1.8
4 2.3
So I would like to plot this two set of data as two different curves, and also I do not know how many lines has each set of data ( or at least this number can change ) so i cannot use every command.( I'm looking for some gnuplot command, not bash command).
Thank you
As you already mentioned every will not work here, since you have variable lengths of datasets (edit: yes it will, see edit below).
In case you had two empty lines to separate your datasets you could use index, check help index.
However, if you have a single empty line, pseudocolumn -1 will help. Check help pseudocolumns.
Then you can define a filter with the ternary operator, check help ternary.
Code:
### plotting variable datasets
reset session
$Data <<EOD
#First set of data
#Time #Velocity
1 0.3
2 0.5
3 0.8
4 1.3
#Second set of data
#Time #Velocity
1 0.7
2 0.9
3 1.8
#Third set of data
#Time #Velocity
1 0.9
2 1.4
3 2.6
4 3.6
5 4.8
EOD
myFilter(col,i) = column(-1)==i-1 ? column(col) : NaN
set key top left
plot for [i=1:3] $Data u 1:(myFilter(2,i)) w lp pt 7 title sprintf("Set %d",i)
### end of code
Edit: (as #binzo pointed out)
Actually, I made it too complicated. As simple as the following will also do it without filter (filter can be used on other occasions). Note, the blocks are numbered starting from 0.
plot for [i=1:3] $Data u 1:2 every :::i-1::i-1 w lp pt 7 title sprintf("Set %d",i)
Result:
I would like to print only lines containing the least number in groups. My files contains multiple columns, and I use the first column to determine groups. Let's say 1st, 4th, 6th lines are in the same group because the content of the first column is the same. My goal is to print out a line that contains the least number in the second column for each group.
file.txt:
VDDA 0.7 ....
VDDB 0.2 ....
VDDB 0.3 ....
VDDA 0.4 ....
VSS 0.1 ....
VDDA 0.2 ....
VSS 0.2 ....
output.txt:
VDDA 0.2 ....
VDDB 0.2 ....
VSS 0.1 ....
I think I can do this job with C using a for loop and comparisons, but I think there is a better way using AWK/SED/PERL.
If you are not bothering about the sequence of the 1st field as per Input_file then following may help you in same too. Also this code will be looking for smallest number value for any 1st field and going to print it then.
awk '{a[$1]=a[$1]>$2?$2:(a[$1]?a[$1]:$2)} END{for(i in a){print i,a[i]}}' Input_file
EDIT1: If you want the output in same order as $1 is in, then following may help you in same too.
awk '!a[$1]{b[++i]=$1} {c[$1]=a[$1]>$2?$0:(c[$1]?c[$1]:$0);a[$1]=a[$1]>$2?$2:(a[$1]?a[$1]:$2);} END{for(j=1;j<=i;j++){print b[j],c[b[j]]}}' Input_file
$ awk '{split(a[$1],s);a[$1]=(s[2]<$2 && s[2])?a[$1]:$0} END{for(i in a)print a[i]}' file.txt
VDDA 0.2 ....
VDDB 0.2 ....
VSS 0.1 ....
Brief explanation:
Save $0 into a[$1]
split(a[$1],s): split numeric s[2] from a[$1] for comparing
if the condition s[2]<$2 && s[2] is met, set a[$1]=a[$1], otherwise set a[$1]=$0
With GNU datamash tool:
Assuming the following exemplary input file containing rows with 5 columns:
VDDA 0.7 c1 2 a
VDDB 0.2 c2 3 b
VDDB 0.3 c4 5 c
VDDA 0.4 c5 6 d
VSS 0.1 c6 7 e
VDDA 0.2 c7 8 f
VSS 0.2 c8 9 g
datamash -sWf -g1 min 2 < file | awk '{--NF}1'
The output:
VDDA 0.2 c7 8 f
VDDB 0.2 c2 3 b
VSS 0.1 c6 7 e
I have a file:
1 0.5
2 0.7
3 0.55
4 0.7
5 0.45
6 0.8
7 0.75
8 0.3
9 0.35
10 0.5
11 0.65
12 0.75
I want to split the file into 4 arrays ending on every next 3rd line and then to find the maximum value in the second column for every array. So this file the outcome would be the:
3 0.7
6 0.8
9 0.75
12 0.75
I have managed so far to split the file into several by
awk 'NR%3==1{x="L"++i;}{print > x}' filename
then to find the maximum in every file:
awk 'BEGIN{max=0}{if(($2)>max) max=($2)}END {print $1,max}'
However, this creates additional files which is fine for this example but in reality the original file contains 65 million lines so I will be a bit overwhelmed by the amount of files and I am trying to avoid it by writing a short script which will combine both of the mentioned above.
I tried this one:
awk 'BEGIN {for (i=1; i<=12; i+=3) {max=0} {if(($2)>max) max=($2)}}END {print $1,max}' Filename
but it produces something irrelevant.
So if you can help me out it will be much appreciated!
You could go for something like this:
awk 'NR % 3 == 1 || $2 > max {max = $2} NR % 3 == 0 {print $1, max}' file
The value of max is always reset every three rows and updated if value of the second column is greater than it. At the end of every group of three, the first column and the max are printed.
I have a simple 1x10 vector with percentage values like this:
[0 0.2 0.2 0.4 0 0 0.1 0 0 0.1].
I want to sort them in a descending order without losing track if their respective indexes. I need something like this for example:
0.4 4
0.2 2
0.2 3
0.1 7
0.1 10
0 1
0 5
0 6
0 8
0 9
Thanks for your help, bear with me as I am new to matlab and there so many built-in functions!!
[sorted_vector,idx] = sort(old_vector,'descend');
idx will return the indeces of the sorted vector elements.
'descend' will sort the vector in descending order.
I am trying to add the elements of an array that is defined by user input from the read -a command. How can I do that?
read -a array
tot=0
for i in ${array[#]}; do
let tot+=$i
done
echo "Total: $tot"
Given an array (of integers), here's a funny way to add its elements (in bash):
sum=$(IFS=+; echo "$((${array[*]}))")
echo "Sum=$sum"
e.g.,
$ array=( 1337 -13 -666 -208 -408 )
$ sum=$(IFS=+; echo "$((${array[*]}))")
$ echo "$sum"
42
Pro: No loop, no subshell!
Con: Only works with integers
Edit (2012/12/26).
As this post got bumped up, I wanted to share with you another funny way, using dc, which is then not restricted to just integers:
$ dc <<< '[+]sa[z2!>az2!>b]sb1 2 3 4 5 6 6 5 4 3 2 1lbxp'
42
This wonderful line adds all the numbers. Neat, eh?
If your numbers are in an array array:
$ array=( 1 2 3 4 5 6 6 5 4 3 2 1 )
$ dc <<< '[+]sa[z2!>az2!>b]sb'"${array[*]}lbxp"
42
In fact there's a catch with negative numbers. The number '-42' should be given to dc as _42, so:
$ array=( -1.75 -2.75 -3.75 -4.75 -5.75 -6.75 -7.75 -8.75 )
$ dc <<< '[+]sa[z2!>az2!>b]sb'"${array[*]//-/_}lbxp"
-42.00
will do.
Pro: Works with floating points.
Con: Uses an external process (but there's no choice if you want to do non-integer arithmetic — but dc is probably the lightest for this task).
My code (which I actually utilize) is inspired by answer of gniourf_gniourf. I personally consider this more clear to read/comprehend, and to modify. Accepts also floating points, not just integers.
Sum values in array:
arr=( 1 2 3 4 5 6 7 8 9 10 )
IFS='+' sum=$(echo "scale=1;${arr[*]}"|bc)
echo $sum # 55
With small change, you can get the average of values:
arr=( 1 2 3 4 5 6 7 8 9 10 )
IFS='+' avg=$(echo "scale=1;(${arr[*]})/${#arr[#]}"|bc)
echo $avg # 5.5
gniourf_gniourf's answer is excellent since it doesn't require a loop or bc. For anyone interested in a real-world example, here's a function that totals all of the CPU cores reading from /proc/cpuinfo without messing with IFS:
# Insert each processor core count integer into array
cpuarray=($(grep cores /proc/cpuinfo | awk '{print $4}'))
# Read from the array and replace the delimiter with "+"
# also insert 0 on the end of the array so the syntax is correct and not ending on a "+"
read <<< "${cpuarray[#]/%/+}0"
# Add the integers together and assign output to $corecount variable
corecount="$((REPLY))"
# Echo total core count
echo "Total cores: $corecount"
I also found the arithmetic expansion works properly when calling the array from inside the double parentheses, removing the need for the read command:
cpuarray=($(grep cores /proc/cpuinfo | awk '{print $4}'))
corecount="$((${cpuarray[#]/%/+}0))"
echo "Total cores: $corecount"
Generic:
array=( 1 2 3 4 5 )
sum="$((${array[#]/%/+}0))"
echo "Total: $sum"
I'm a fan of brevity, so this is what I tend to use:
IFS="+";bc<<<"${array[*]}"
It essentially just lists the data of the array and passes it into BC which evaluates it. The "IFS" is the internal field separate, it essentially specifies how to separate arrays, and we said to separate them with plus signs, that means when we pass it into BC, it receives a list of numbers separated by plus signs, so naturally it adds them together.
Another dc & bash method:
arr=(1 3.88 7.1 -1)
dc -e "0 ${arr[*]/-/_} ${arr[*]/*/+} p"
Output:
10.98
The above runs the expression 0 1 3.88 7.1 _1 + + + + p with dc. Note the dummy value 0 because there's one too many +s, and also note the usual negative number prefix - must be changed to _ in dc.
arr=(1 2 3) //or use `read` to fill the array
echo Sum of array elements: $(( ${arr[#]/%/ +} 0))
Sum of array elements: 6
Explanation:
"${arr[#]/%/ +}" will return 1 + 2 + 3 +
By adding additional zero at the end we will get 1 + 2 + 3 + 0
By wrapping this string with BASH's math operation like this$(( "${arr[#]/%/ +} 0")), it will return the sum instead
This could be used for other math operations.
For subtracting just use - instead
For multiplication use * and 1 instead of 0
Can be used with logic operators too.
BOOL AND EXAMPLE - check if all items are true (1)
arr=(1 0 1)
if [[ $((${arr[#]/%/ &} 1)) -eq 1 ]]; then echo "yes"; else echo "no"; fi
This will print: no
BOOL OR EXAMPLE - check if any item is true (1)
arr=(1 0 0)
if [[ $((${arr[#]/%/ |} 0)) -eq 1 ]]; then echo "yes"; else echo "no"; fi
This will print: yes
A simple way
function arraySum
{
sum=0
for i in ${a[#]};
do
sum=`expr $sum + $i`
done
echo $sum
}
a=(7 2 3 9)
echo -n "Sum is = "
arraySum ${a[#]}
I find this very simple using an increasing variable:
result2=0
for i in ${lineCoffset[#]};
do
result2=$((result2+i))
done
echo $result2