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Today's Topics:
1. Re: import question (Bob Ippolito)
2. Re: import question (Galaxy Being)
3. Re: import question (Bob Ippolito)
----------------------------------------------------------------------
Message: 1
Date: Wed, 17 Feb 2021 18:36:45 -0800
From: Bob Ippolito <b...@redivi.com>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners@haskell.org>
Subject: Re: [Haskell-beginners] import question
Message-ID:
<cacwmpm8j_dorfa__gilcpv+4swpqhsm4ucgvb8r6zxe22wt...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
You don't need to do any rounding if the list is already Decimal.
If you wanted to format a Double with some specific decimal representation
you could look at Numeric.showFFloatAlt or similar.
import Data.Decimal
dList :: [Decimal]
dList = [1.00,1.01..2.00]
main = print dList
On Wed, Feb 17, 2021 at 5:27 PM Galaxy Being <borg...@gmail.com> wrote:
> I'm trying to create a list of real numbers with a two-decimal interval, a
> la
>
> > [1.0,1.01,1.02,...1.99,2.00]
>
> however, I get the float approximation problem
>
>
> [1.0,1.01,1.02,1.03,1.04,1.05,1.06,1.07,1.08,1.09,1.1,1.11,1.12,1.1300000000000001,1.1400000000000001,...
>
> So I attempted to compensate with
>
> import Data.Decimal
> map (roundTo 2) [1.00,1.01..2.0]
>
> I don't have to do it this way if there is another rounding function to
> correct the float overrun issue.
>
>
>
> On Wed, Feb 17, 2021 at 2:43 PM Francesco Ariis <fa...@ariis.it> wrote:
>
>> Il 17 febbraio 2021 alle 14:17 Galaxy Being ha scritto:
>> > How would I install it globally? I'm not using projects, I'm just at the
>> > ghci REPL.
>>
>> Most likely
>>
>> cabal install --lib Decimal
>>
>> Check what Tom has said too —F
>> _______________________________________________
>> Beginners mailing list
>> Beginners@haskell.org
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>>
> _______________________________________________
> Beginners mailing list
> Beginners@haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
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Message: 2
Date: Wed, 17 Feb 2021 21:42:02 -0600
From: Galaxy Being <borg...@gmail.com>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners@haskell.org>
Subject: Re: [Haskell-beginners] import question
Message-ID:
<cafahfsutj1unk8h4a8ikezvcyxn7z7rsa1uzwbw99ki2svj...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
As I've said, working at the ghci REPL,
import Data.Decimal
dList :: [Decimal]
dList = [1.00,1.01..2.00]
main = print dList
errors out
: <interactive>:76:11-17: error:
: Not in scope: type constructor or class `Decimal'
On Wed, Feb 17, 2021 at 8:37 PM Bob Ippolito <b...@redivi.com> wrote:
> You don't need to do any rounding if the list is already Decimal.
>
> If you wanted to format a Double with some specific decimal representation
> you could look at Numeric.showFFloatAlt or similar.
>
> import Data.Decimal
>
> dList :: [Decimal]
> dList = [1.00,1.01..2.00]
>
> main = print dList
>
>
>
> On Wed, Feb 17, 2021 at 5:27 PM Galaxy Being <borg...@gmail.com> wrote:
>
>> I'm trying to create a list of real numbers with a two-decimal interval,
>> a la
>>
>> > [1.0,1.01,1.02,...1.99,2.00]
>>
>> however, I get the float approximation problem
>>
>>
>> [1.0,1.01,1.02,1.03,1.04,1.05,1.06,1.07,1.08,1.09,1.1,1.11,1.12,1.1300000000000001,1.1400000000000001,...
>>
>> So I attempted to compensate with
>>
>> import Data.Decimal
>> map (roundTo 2) [1.00,1.01..2.0]
>>
>> I don't have to do it this way if there is another rounding function to
>> correct the float overrun issue.
>>
>>
>>
>> On Wed, Feb 17, 2021 at 2:43 PM Francesco Ariis <fa...@ariis.it> wrote:
>>
>>> Il 17 febbraio 2021 alle 14:17 Galaxy Being ha scritto:
>>> > How would I install it globally? I'm not using projects, I'm just at
>>> the
>>> > ghci REPL.
>>>
>>> Most likely
>>>
>>> cabal install --lib Decimal
>>>
>>> Check what Tom has said too —F
>>> _______________________________________________
>>> Beginners mailing list
>>> Beginners@haskell.org
>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>>>
>> _______________________________________________
>> Beginners mailing list
>> Beginners@haskell.org
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>>
> _______________________________________________
> Beginners mailing list
> Beginners@haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
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------------------------------
Message: 3
Date: Wed, 17 Feb 2021 20:29:22 -0800
From: Bob Ippolito <b...@redivi.com>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <beginners@haskell.org>
Subject: Re: [Haskell-beginners] import question
Message-ID:
<cacwmpm-sat9fn+-tqzxmdupnt+o+xejxyn_fynx3ufzhq1-...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Like others said, you'll need to install the Decimal package in order to
use Data.Decimal.
If you really wanted to do it with a floating point type and no
dependencies you can use showFFloatAlt from Numeric to display with a
specified precision.
import Numeric
import Text.Show
main = putStrLn . showListWith (showFFloatAlt (Just 2)) [1.00, 1.01 ..
2.00] $ ""
On Wed, Feb 17, 2021 at 7:42 PM Galaxy Being <borg...@gmail.com> wrote:
> As I've said, working at the ghci REPL,
>
> import Data.Decimal
> dList :: [Decimal]
> dList = [1.00,1.01..2.00]
> main = print dList
>
> errors out
>
> : <interactive>:76:11-17: error:
> : Not in scope: type constructor or class `Decimal'
>
>
>
> On Wed, Feb 17, 2021 at 8:37 PM Bob Ippolito <b...@redivi.com> wrote:
>
>> You don't need to do any rounding if the list is already Decimal.
>>
>> If you wanted to format a Double with some specific decimal
>> representation you could look at Numeric.showFFloatAlt or similar.
>>
>> import Data.Decimal
>>
>> dList :: [Decimal]
>> dList = [1.00,1.01..2.00]
>>
>> main = print dList
>>
>>
>>
>> On Wed, Feb 17, 2021 at 5:27 PM Galaxy Being <borg...@gmail.com> wrote:
>>
>>> I'm trying to create a list of real numbers with a two-decimal interval,
>>> a la
>>>
>>> > [1.0,1.01,1.02,...1.99,2.00]
>>>
>>> however, I get the float approximation problem
>>>
>>>
>>> [1.0,1.01,1.02,1.03,1.04,1.05,1.06,1.07,1.08,1.09,1.1,1.11,1.12,1.1300000000000001,1.1400000000000001,...
>>>
>>> So I attempted to compensate with
>>>
>>> import Data.Decimal
>>> map (roundTo 2) [1.00,1.01..2.0]
>>>
>>> I don't have to do it this way if there is another rounding function to
>>> correct the float overrun issue.
>>>
>>>
>>>
>>> On Wed, Feb 17, 2021 at 2:43 PM Francesco Ariis <fa...@ariis.it> wrote:
>>>
>>>> Il 17 febbraio 2021 alle 14:17 Galaxy Being ha scritto:
>>>> > How would I install it globally? I'm not using projects, I'm just at
>>>> the
>>>> > ghci REPL.
>>>>
>>>> Most likely
>>>>
>>>> cabal install --lib Decimal
>>>>
>>>> Check what Tom has said too —F
>>>> _______________________________________________
>>>> Beginners mailing list
>>>> Beginners@haskell.org
>>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>>>>
>>> _______________________________________________
>>> Beginners mailing list
>>> Beginners@haskell.org
>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>>>
>> _______________________________________________
>> Beginners mailing list
>> Beginners@haskell.org
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>>
> _______________________________________________
> Beginners mailing list
> Beginners@haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
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