Rounding off real (floating point) values - bash to awk

Rounding off real (floating point) values - bash to awk

[Lester Anderson]

Hello,

I can use a script like:

#!/bin/bash
x=3.7
# pass variable x to awk via -v (var=value)
awk -v x=$x 'BEGIN { printf "%3.0f\n", x }'
#

which returns the value 4 as expected, but are there any other methods
that can be used?

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Re: Rounding off real (floating point) values - bash to awk

[Eliot Moss]

On 11/26/2015 8:24 AM, Lester Anderson wrote:
> Hello,
>
> I can use a script like:
>
> #!/bin/bash
> x=3.7
> # pass variable x to awk via -v (var=value)
> awk -v x=$x 'BEGIN { printf "%3.0f\n", x }'
> #
>
> which returns the value 4 as expected, but are there any other methods
> that can be used?

In bash this must be a string (bash uses only fixed width integers for numbers),
so you can put as many decimal places as you like.  awk will treat it as a string
or floating point number, depending on context.  The f output format forces conversion.
Another way is to do arithmetic;  even x+0 will do it.  IIRC, all numbers in awk are
doubles (IEEE 64-bit floats).  The documentation on awk can tell you more about
conversions, rounding, etc.

Regards -- Eliot Moss

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Re: Rounding off real (floating point) values - bash to awk

[Duncan Roe]

On Thu, Nov 26, 2015 at 09:18:52AM -0500, Eliot Moss wrote:
> On 11/26/2015 8:24 AM, Lester Anderson wrote:
> >Hello,
> >
> >I can use a script like:
> >
> >#!/bin/bash
> >x=3.7
> ># pass variable x to awk via -v (var=value)
> >awk -v x=$x 'BEGIN { printf "%3.0f\n", x }'
> >#
> >
> >which returns the value 4 as expected, but are there any other methods
> >that can be used?
>
> In bash this must be a string (bash uses only fixed width integers for numbers),
> so you can put as many decimal places as you like.  awk will treat it as a string
> or floating point number, depending on context.  The f output format forces conversion.
> Another way is to do arithmetic;  even x+0 will do it.  IIRC, all numbers in awk are
> doubles (IEEE 64-bit floats).  The documentation on awk can tell you more about
> conversions, rounding, etc.
>
> Regards -- Eliot Moss
>
You can skip using awk: under bash 'printf "%3.0f\n" 3.7' gives "  4".
Or 'printf "%.0f\n" 3.7' gives 4,

Cheers ... Duncan.

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Re: Rounding off real (floating point) values - bash to awk

[Steven Penny]

On Thu, Nov 26, 2015 at 7:24 AM, Lester Anderson wrote:
> x=3.7
> awk -v x=$x 'BEGIN { printf "%3.0f\n", x }'
> which returns the value 4 as expected, but are there any other methods
> that can be used?

echo 3.7 | awk '{printf "%.0f", $0}'

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Re: Rounding off real (floating point) values - bash to awk

[Steven Penny]

On Thu, Nov 26, 2015 at 10:29 AM, Steven Penny wrote:
> echo 3.7 | awk '{printf "%.0f", $0}'

Another option

awk 'BEGIN {printf "%.0f", ARGV[1]}' 3.7

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Re: Rounding off real (floating point) values - bash to awk

[Helmut Karlowski]

---------------------------------------------------
> On Thu, Nov 26, 2015 at 10:29 AM, Steven Penny wrote:
> > echo 3.7 | awk '{printf "%.0f", $0}'
> 
> Another option
> 
> awk 'BEGIN {printf "%.0f", ARGV[1]}' 3.7

#4: 

printf "%3.0f\n" 3.7

-Helmut


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Re: Rounding off real (floating point) values - bash to awk

[Achim Gratz]

Lester Anderson writes:
[…]

By now, none of what you ask has anything to do with Cygwin anymore.
Please consider chosing a more appropriate forum for your questions.


Regards,
Achim.
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