Bash Excercise - simple matrix

escuire · 2013-05-28 08:48:21

How to write script which output will be a matrix like mentioned below?
This is an example for argument = 5, where argument means number of columns and rows. Numbers range could be from 1 - 9.
1 2 3 4 5
6 7 8 9 1
2 3 4 5 6
7 8 9 1 2
3 4 5 6 7

Thx in advance!

jasonwryan · 2013-05-28 08:58:26

What have you tried?

escuire · 2013-05-28 11:29:53

So far I managed to display this:
1 2 3 4 5
6 7 8 9

#!/bin/bash

# Defining matrix parameters
# array a = ( 1 2 3 4 ... 9 )
a=({1..9})
cols=$1
rows=$1

# Dispalying matrix

for ((row=1; row<=rows; row++)); do
for ((col=1; col<=cols; col++)); do
echo -n ${a[((cols*((row-1))+col-1))]}$'\t'
done
echo
done

karol · 2013-05-28 11:39:40

1. Does it have to be just bash or can you use some coreutils?
2. Random numbers between 1 and 9 or just like you showed in your first post: all numbers from 1 to 9 and from 1 again?

portix · 2013-05-28 11:44:44

Try the following:

for ((i=0;i<rows;i++)); do 
    for((j=0;j<cols;j++)); do 
        printf "%d\t" ${a[$(((j+rows*i)%${#a[@]}))]}; 
    done; 
    printf "\n"; 
done

escuire · 2013-05-28 11:47:18

Just bash unfortunately...and it has to be just like I showed. So after 9 should me again 1 and in the next line 2 3 4 5 6, etc. It was example for argument = 5, but it has to work for every number in input.

Trilby · 2013-05-28 11:48:25

Is this homework?

It can be done in four clean lines. with only one variable needed. (Or on one line that would fit on an 80-column terminal).

Last edited by Trilby (2013-05-28 11:52:21)

escuire · 2013-05-28 11:52:57

yes, but I am learning by myself. I found this exercise on some webpage. If you see different solution I am open to see that.

Trilby · 2013-05-28 11:56:56

for i in $(seq $(($1*$1))); do
	printf "%d\t" $((($i-1)%9+1))
	[[ $(($i%$1)) -eq 0 ]] && echo
done

EDIT: oops, not quite right, standby. fixed.

Last edited by Trilby (2013-05-28 12:04:01)

escuire · 2013-05-28 12:04:52

Thank you for your help. This is what I was looking for:

printf "%d\t" ${a[$(((j+rows*i)%${#a[@]}))]};

jasonwryan · 2013-05-28 18:04:54

Please mark your thread as [Solved] by editing your first post and prepending it to the title.

Also, please use code tags when pasting to the boards: https://wiki.archlinux.org/index.php/Fo … s_and_Code

args · 2013-05-29 07:09:45

for i in {1..25};do echo $(($RANDOM%9+1)); done|xargs -n 5

how about this?

karol · 2013-05-29 08:38:39

args wrote:

for i in {1..25};do echo $(($RANDOM%9+1)); done|xargs -n 5

how about this?

I asked about this: https://bbs.archlinux.org/viewtopic.php … 9#p1279109
The answer https://bbs.archlinux.org/viewtopic.php … 2#p1279112

Edit: Your code would have to work for any number, not just 5.

Last edited by karol (2013-05-29 08:39:41)

Procyon · 2013-05-29 09:00:48

yes "$(seq 9)" | head -n $((5 * 5)) | pr -aT -5

Arch Linux

#1 2013-05-28 08:48:21

Bash Excercise - simple matrix

#2 2013-05-28 08:58:26

Re: Bash Excercise - simple matrix

#3 2013-05-28 11:29:53

Re: Bash Excercise - simple matrix

#4 2013-05-28 11:39:40

Re: Bash Excercise - simple matrix

#5 2013-05-28 11:44:44

Re: Bash Excercise - simple matrix

#6 2013-05-28 11:47:18

Re: Bash Excercise - simple matrix

#7 2013-05-28 11:48:25

Re: Bash Excercise - simple matrix

#8 2013-05-28 11:52:57

Re: Bash Excercise - simple matrix

#9 2013-05-28 11:56:56

Re: Bash Excercise - simple matrix

#10 2013-05-28 12:04:52

Re: Bash Excercise - simple matrix

#11 2013-05-28 18:04:54

Re: Bash Excercise - simple matrix

#12 2013-05-29 07:09:45

Re: Bash Excercise - simple matrix

#13 2013-05-29 08:38:39

Re: Bash Excercise - simple matrix

#14 2013-05-29 09:00:48

Re: Bash Excercise - simple matrix

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