# Round off Number in File **URL:** \ **Category:** Shell Programming and Scripting\ **Created:** [February 2, 2015, 12:19pm UTC](https://community.unix.com/t/round-off-number-in-file/350092 "2015-02-02T12:19:18Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![rohit\_shinez](https://community.unix.com/letter_avatar/rohit_shinez/32/6_449c533f586939b6e5f246632a46421f.png) [@rohit\_shinez](https://community.unix.com/u/rohit_shinez)\ **Post date:** [February 2, 2015, 12:19pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/1 "2015-02-02T12:19:18Z")
Hi Guys, i am having a csv file where i need to round off numerical column to 2 decimal precision in specific columns. i need to ignore the first two line i.e the header columns and manipulate rest of the lines of the csv file. My columns are specific i.e i need to round off only 2nd,4th and 6th field of the file without affecting other fields. ```nohighlight heading head1,head2,head3,head4,head5,head6 aa,12,bb,-123,cc,0 bb,-12.456666,zz,-123.23333,cc,12.1 ``` i need the below output ```nohighlight heading head1,head2,head3,head4,head5,head6 aa,12.00,bb,-123.00,cc,0.00 bb,-12.45,zz,-123.23,cc,12.10 ``` I have tried with below ```nohighlight head -2 file.csv>file.tmp awk 'BEGIN{OFS=FS=","} { $2=sprintf("%.2f",$2) $4=sprintf("%.2f",$4) $6=sprintf("%.2f",$6) }1' file.csv >file_conv.tmp tail +2 file_conv.tmp>>file.tmp mv file.tmp > file.csv ``` ---
**Author:** ![Corona688](https://community.unix.com/letter_avatar/corona688/32/6_449c533f586939b6e5f246632a46421f.png) [@Corona688](https://community.unix.com/u/Corona688)\ **Post date:** [February 2, 2015, 12:34pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/2 "2015-02-02T12:34:52Z")
And what did it do? ---
**Author:** ![senhia83](https://community.unix.com/letter_avatar/senhia83/32/6_449c533f586939b6e5f246632a46421f.png) [@senhia83](https://community.unix.com/u/senhia83)\ **Post date:** [February 2, 2015, 12:36pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/3 "2015-02-02T12:36:00Z")
Try ```nohighlight awk -F, 'NR>2{ for ( i = 2 ; i<=6; i=i+2 ) { $i=sprintf("%.2f",$i); }}1' OFS="," file ``` ---
**Author:** ![Scrutinizer](https://community.unix.com/user_avatar/community.unix.com/scrutinizer/32/1216_2.png) [@Scrutinizer](https://community.unix.com/u/Scrutinizer)\ **Post date:** [February 2, 2015, 12:38pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/4 "2015-02-02T12:38:40Z")
Try this small change to your own code: ```nohighlight awk 'BEGIN{OFS=FS=","} NR>2 { $2=sprintf("%.2f",$2) $4=sprintf("%.2f",$4) $6=sprintf("%.2f",$6) }1' file.csv ``` ---
**Author:** ![rohit\_shinez](https://community.unix.com/letter_avatar/rohit_shinez/32/6_449c533f586939b6e5f246632a46421f.png) [@rohit\_shinez](https://community.unix.com/u/rohit_shinez)\ **Post date:** [February 2, 2015, 12:45pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/5 "2015-02-02T12:45:15Z")
> [@senhia83](#): > > Try > > ```plaintext > awk -F, 'NR>2{ for ( i = 2 ; i<=6; i=i+2 ) { $i=sprintf("%.2f",$i); }}1' OFS="," file > > ``` Just a few suggestion its just a sample file my csv is having more than 6 fields so 6th field is not the last field and also my file size is huge having lines of more than 2 lakh will it be faster using awk ---------- Post updated at 12:45 PM ---------- Previous update was at 12:43 PM ---------- > [@scrutinizer](#): > > Try this small change to your own code: > > ```plaintext > awk 'BEGIN{OFS=FS=","} > NR>2 { > $2=sprintf("%.2f",$2) > $4=sprintf("%.2f",$4) > $6=sprintf("%.2f",$6) > }1' file.csv > > ``` Hi is it way to perform in better way i mean taking performance in do consideration since i would process more than 2 lakh line records ---
**Author:** ![senhia83](https://community.unix.com/letter_avatar/senhia83/32/6_449c533f586939b6e5f246632a46421f.png) [@senhia83](https://community.unix.com/u/senhia83)\ **Post date:** [February 2, 2015, 12:47pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/6 "2015-02-02T12:47:03Z")
> [@rohit\_shinez](#): > > Just a few suggestion its just a sample file my csv is having more than 6 fields so 6th field is not the last field and also my file size is huge having lines of more than 2 lakh will it be faster using awk I didnt get your point, if you want all the even number fields to be rounded, just replace the `6 in the for loop by NF` , ,, `awk` is the fastest in these type of manipulations as I know.. It doesnt matter how many fields you have,, this script should work as long as you know which fields to round... ---
**Author:** ![Scrutinizer](https://community.unix.com/user_avatar/community.unix.com/scrutinizer/32/1216_2.png) [@Scrutinizer](https://community.unix.com/u/Scrutinizer)\ **Post date:** [February 2, 2015, 12:49pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/7 "2015-02-02T12:49:10Z")
> [@rohit\_shinez](#): > > [..] > Hi is it way to perform in better way i mean taking performance in do consideration since i would process more than 2 lakh line records Hi rohit\_shinez, 200,000 lines isn't that much. I would just try it out and see if it is fast enough... ---
**Author:** ![rohit\_shinez](https://community.unix.com/letter_avatar/rohit_shinez/32/6_449c533f586939b6e5f246632a46421f.png) [@rohit\_shinez](https://community.unix.com/u/rohit_shinez)\ **Post date:** [February 2, 2015, 12:51pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/8 "2015-02-02T12:51:17Z")
> [@senhia83](#): > > I didnt get your point, if you want all the even number fields to be rounded, just replace the `6 in the for loop by NF` , ,, `awk` is the fastest in these type of manipulations as I know.. ideally its not all the even fields i would say its like some specific fields in my file but not the 6th field as last filed for taking consider the below file ```plaintext heading head1,head2,head3,head4,head5,head6 aa,12,bb,-123,cc,0,aa,12,bb,-1231231.111,cc,0,aa,12,bb,-123,cc,abnnn ``` ---------- Post updated at 12:51 PM ---------- Previous update was at 12:50 PM ---------- > [@scrutinizer](#): > > Hi rohit\_shinez, 2 lakh isn't that much. I would just try it out and see if it is fast enough... I mean will there be any better approach apart from mine ---
**Author:** ![Scrutinizer](https://community.unix.com/user_avatar/community.unix.com/scrutinizer/32/1216_2.png) [@Scrutinizer](https://community.unix.com/u/Scrutinizer)\ **Post date:** [February 2, 2015, 12:53pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/9 "2015-02-02T12:53:08Z")
> [@rohit\_shinez](#): > > i[..] > I mean will there be any better approach apart from mine It seems like a good approach to me.. ---
**Author:** ![rohit\_shinez](https://community.unix.com/letter_avatar/rohit_shinez/32/6_449c533f586939b6e5f246632a46421f.png) [@rohit\_shinez](https://community.unix.com/u/rohit_shinez)\ **Post date:** [February 2, 2015, 1:00pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/10 "2015-02-02T13:00:53Z")
> [@scrutinizer](#): > > It seems like a good approach to me.. Is it possible to make use of the snippet in generic function way like calling the function name say round\_number 0.2decimal col2 col4 col5 col7 .... ---
**Author:** ![RudiC](https://community.unix.com/letter_avatar/rudic/32/6_449c533f586939b6e5f246632a46421f.png) [@RudiC](https://community.unix.com/u/RudiC)\ **Post date:** [February 2, 2015, 1:23pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/11 "2015-02-02T13:23:14Z")
Try also ```nohighlight awk 'BEGIN {OFS=FS=","} NR>2 {$2+=0.0001 $4+=0.0001 $6+=0.0001 } 1 ' CONVFMT="%.2f" file heading head1,head2,head3,head4,head5,head6 aa,12.00,bb,-123.00,cc,0.00 bb,-12.46,zz,-123.23,cc,12.10 ``` ---------- Post updated at 19:23 ---------- Previous update was at 19:14 ---------- Strange enough, this is slower than the explicit `sprint` approach. Of course, it has to run through the format conversion routines after each of the addition operations... ---
**Author:** ![rohit\_shinez](https://community.unix.com/letter_avatar/rohit_shinez/32/6_449c533f586939b6e5f246632a46421f.png) [@rohit\_shinez](https://community.unix.com/u/rohit_shinez)\ **Post date:** [February 2, 2015, 1:25pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/12 "2015-02-02T13:25:08Z")
Thanks rudic As I said in my previous post will it be able to make it in generic function based script like Round\_function decimalvalue col1 col2 ..... ... So that I can use wat decimal precision to round off and which all columns needs to be changed ---
**Author:** ![RudiC](https://community.unix.com/letter_avatar/rudic/32/6_449c533f586939b6e5f246632a46421f.png) [@RudiC](https://community.unix.com/u/RudiC)\ **Post date:** [February 2, 2015, 1:34pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/13 "2015-02-02T13:34:36Z")
Try ```nohighlight awk 'BEGIN {OFS=FS=","} function roundit(FIELDS) {split (FIELDS, TMP) for (t in TMP) $(TMP[t])+=0.0001 } NR>2 {roundit("2 4 6") } 1 ' CONVFMT="%.2f" file ``` Surprisingly enough, this nearly cuts the time consumed in half ...! ---
**Author:** ![rohit\_shinez](https://community.unix.com/letter_avatar/rohit_shinez/32/6_449c533f586939b6e5f246632a46421f.png) [@rohit\_shinez](https://community.unix.com/u/rohit_shinez)\ **Post date:** [February 2, 2015, 1:41pm UTC](https://community.unix.com/t/round-off-number-in-file/350092/14 "2015-02-02T13:41:24Z")
Round it function needs to called like this Roundit decimal\_precision fields Filename So that i can use it in generic way of how many decimal precision you need and which all columns you want to make the changes ```nohighlight awk 'BEGIN {OFS=FS=","} function roundit(FIELDS) {split (FIELDS, TMP) for (t in TMP) $(TMP[t])+=0.0001 } NR>2 {roundit("$1 $2 $3") } 1 ' CONVFMT="%.2f" $4 ```