View Spreadsheet.hs
module Spreadsheet where
import Control.Applicative
import Control.Monad (forM_)
import Data.IORef
import Data.List (union)
import Data.Unique
View design.hs
select [] = []
select (x:xs) = (x,xs) : select xs
pairs nums = [(a, b) | (a, bs) <- select nums, b <- bs]
triples nums = [(a,b,c) | (a,bs) <- select nums, (b,cs) <- select bs, c <- cs]
overlap (a,b,c) (d,e,f) =
case compare a d of
View interpreter.hs
import Data.Map (Map, (!), insert, empty)
import Control.Monad.State (StateT, put, get, liftIO, evalStateT)
type Val = Int
type Var = String
data Instruction =
Set Val Var
| Print Var
| Add Var Var Var
View FXForwards.html
<h1 id="fx-forwards">FX Forwards</h1>
<p>The standard no-arbitrage price <span class="MathJax_Preview"></span><span class="MathJax" id="MathJax-Element-1-Frame" role="textbox" aria-readonly="true"><nobr><span class="math" id="MathJax-Span-1" style="width: 2.069em; display: inline-block;"><span style="display: inline-block; position: relative; width: 1.715em; height: 0px; font-size: 121%;"><span style="position: absolute; clip: rect(1.243em 1000.003em 2.6em -0.469em); top: -2.122em; left: 0.003em;"><span class="mrow" id="MathJax-Span-2"><span class="msubsup" id="MathJax-Span-3"><span style="display: inline-block; position: relative; width: 1.656em; height: 0px;"><span style="position: absolute; clip: rect(1.243em 1000.003em 2.305em -0.469em); top: -2.122em; left: 0.003em;"><span class="mi" id="MathJax-Span-4" style="font-family: MathJax_Math; font-style: italic;">F<span style="display: inline-block; overflow: hidden; height: 1px; width: 0.121em;"></span></span><span style="display: inline-block; width: 0px; h

FX Forwards

The standard no-arbitrage price $F_{t,T}$ for currency forwards when the spot price is $S_t$, the domestic rate is $r_d$ and the foreign rate is $r_f$ is

$$F_{t,T} = S_t (1 + (r_d-r_f)(T-t) )$$

and the price time $\delta t$ later is

(* Define monadic operations for a list *)
let return x = [x]
let (>>=) lst f = List.concat ( f lst)
(* Generate the combinations of k distinct objects from a list *)
(* Simple version
View golfsort.hs
sortBy[]) -- O(n log n)
where m[]=[];m[x]=x;m x=m(n x);n[]=[];n[x]=[x];n(x:y:z)=p x y:n z
p[]y=y;p x[]=x;p (w:x)(y:z)=case c w y of GT->y:p(w:x)z;_->w:p x(y:z)
sort x=m(map(:[])x)
where m[]=[];m[x]=x;m x=m(n x);n[]=[];n[x]=[x];n(x:y:z)=p x y:n z
p[]y=y;p x[]=x;p (w:x)(y:z)=if w>y then y:p(w:x)z else w:p x(y:z)
View wordgame.hs
import Control.Applicative
import qualified Data.Set as Set
import AI.Search.Uninformed
step :: Set.Set String -> String -> [] String
step wordlist xs = Set.toList . Set.fromList . filter f $ remove1 xs ++ swap1 xs ++ add1 xs
f w = Set.member w wordlist
len = length xs
letters = ['a'..'z']
View dicegame.hs
import Control.Probability
expected p = expectation (runProb p)
die = uniform [1..6] :: Bayes Double Integer
game n
| n == 0 = die
| otherwise = do
x <- die
View ai-examples.hs
module AI.Search.Examples.Graph where
import Control.Monad
import Control.Monad.ST
import Control.Applicative
import Data.STRef
import Data.Map (Map, (!))
import qualified Data.Map as Map
import Data.List (nub)
import Data.Graph.Inductive (LNode, LEdge, Gr)