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Re: when map a tuple of double to a double, it return nothing

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meInvent bbird <jobmattcon@gmail.com> writes:

> after checking many times, do not know where is wrong
>
> when map a tuple of double to a double, it return nothing
>
> import Data.List
> import Control.Monad
> import Math.Combinat
> import System.IO
> import Data.Map (Map)
> import qualified Data.Map as Map
> let allparams = replicateM 2 [0.0, 1.0]
> let a1 = [0.0, 1.0, 1.0, 1.0]
>
>
> let { op1 :: Map (Double, Double) Double; op1 = Map.fromList
> [((allparams!!i!!0, allparams!!i!!1), a1!!i) | i <- [0..3] ] }
> Map.lookup (0.0,0.0) $ op1
> Map.lookup (0.0,0.1) $ op1
> Map.lookup (0.1,0.0) $ op1
> Map.lookup (0.1,0.1) $ op1
>
>
> *Main Data.Map Map> Map.lookup (0.0,0.0) $ op1
> Just 0.0
> *Main Data.Map Map> Map.lookup (0.0,0.1) $ op1
> Nothing
> *Main Data.Map Map> Map.lookup (0.1,0.0) $ op1
> Nothing
> *Main Data.Map Map> Map.lookup (0.1,0.1) $ op1
> Nothing

Check the data.  0.1 /= 1.0.

<snip>
-- 
Ben.

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when map a tuple of double to a double, it return nothing meInvent bbird <jobmattcon@gmail.com> - 2016-07-17 23:58 -0700
  Re: when map a tuple of double to a double, it return nothing Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-07-18 10:15 +0100
    Re: when map a tuple of double to a double, it return nothing meInvent bbird <jobmattcon@gmail.com> - 2016-07-18 02:20 -0700

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