{-| 
    Module      :  Main
    Description :  simple examples of using AERN-RnToRm
    Copyright   :  (c) Michal Konecny
    License     :  BSD3

    Maintainer  :  mik@konecny.aow.cz
    Stability   :  experimental
    Portability :  portable

    Simple examples of using AERN-RnToRm.
-}
module Main where

import qualified Data.Number.ER.RnToRm as AERNFunc
import qualified Data.Number.ER.Real.DomainBox as DBox

import qualified Data.Number.ER.Real as AERN

import Data.Number.ER.Misc

type B = AERN.BM -- use machine double as a basis
type RA = AERN.RA B 
type IRA = AERN.IRA B
type FAPWP = AERNFunc.FAPWP B 

-- function f(x) = x for x in [0,1]:
x :: FAPWP
x =
    AERNFunc.setMaxDegree 2 $
    AERNFunc.proj (DBox.fromAscList [(0,(0) AERN.\/ 1)]) 0
-- function f(x1) = x1 for x1 in [0,1]:
x1 :: FAPWP
x1 =
    AERNFunc.setMaxDegree 2 $
    AERNFunc.proj (DBox.fromAscList [(1,(0) AERN.\/ 1)]) 1

-- domains combined automatically:
fn1 :: FAPWP
fn1 = 2*x + x1

-- ensure the piecewise representation has 4 segments:
fn1depth2 :: FAPWP
fn1depth2 = AERNFunc.bisectUnbisectDepth 2 fn1

-- apply sine pointwise to the function enclosure:
fn2 :: FAPWP
fn2 = 
--    AERN.sin 10 fn1depth2
    AERN.sin 15 fn1depth2

-- evaluate the function at point x = 0.1, x1 = 0.1:
fn2at0101 :: IRA
[fn2at0101] = 
    AERNFunc.eval (DBox.fromList [(0,0.1), (1,0.1)]) fn2

-- partially evaluate fn2 at x1 = 1:
fn3 :: FAPWP
fn3 = AERNFunc.partialEval (DBox.fromList [(1,1)]) fn2

-- integrate fn3 by x with value 1 at origin x = 1:
fn4 :: FAPWP
fn4 = 
    AERNFunc.integrate ix fn2 var span origin value
    where
    ix = 2 -- effort index
    var = 0
    span = DBox.noinfo -- integrate over the whole domain
    origin = 1
    value = 1

-- integrate fn2 by x1 with value (1 - x) at origin x1 = 0:
fn5 :: FAPWP
fn5 =
    AERNFunc.integrate ix fn2 var span origin value
    where
    ix = 2 -- effort index
    var = 1
    span = DBox.noinfo -- integrate over the whole domain
    origin = 0
    value = 1 - x


main = 
    do
    AERN.initialiseBaseArithmetic (0 :: RA)
    putStrLn "****************************************"
    putStrLn "Testing polynomial enclosure arithmetic:"
    putStrLn "****************************************"
    putStrLn "**** Projections:"
    putStrLn $
        "x =\n  " ++ show x
    putStrLn $
        "\nx1 =\n  " ++ show x1
    putStrLn "\n**** Merging domains:"
    putStrLn $
        "2*x + x1 =\n  " ++ showHead 12 fn1
    putStrLn "\n**** Bisection depth 2:"
    putStrLn $
        "2*x + x1 =\n  " ++ showHead 17 fn1depth2
    putStrLn "\n**** Elementary functions:"
    putStrLn $
        "sin(2*x + x1) =\n  " ++ showHead 17 fn2
    putStrLn "\n**** Evaluation:"
    putStrLn $
        "sin(2*x + x1)[x = 0.1, x1 = 0.1] = sin(0.3) = \n  " ++ show fn2at0101
    putStrLn "\n**** Partial evaluation:"
    putStrLn $
        "sin(2*x + x1)[x1 = 1] = sin(5*x + 1) = \n  " ++ showHead 15 fn3
    putStrLn "\n**** Integration of 1-dim function:"
    putStrLn $
        "f(x) = (Int sin(2*x + 1) dx) [f(1) = 1] =\n  " ++ showHead 15 fn4
    putStrLn "\n**** Integration of 2-dim function:"
    putStrLn $
        "f(x,x1) = (Int sin(2*x + x1) dx1) [f(x,1) = 1 - x] =\n  " ++ showHead 17 fn5

showHead n = showFirstLastLines n 0