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View GitHub Profile
View haskellDB.hs
import Database.HDBC
import Database.HDBC.ODBC
data Person = Person
{ id :: Int
, name :: [Char] }
deriving Show
convRow :: [SqlValue] -> Person
convRow [sqlId, sqlDesc] =
View clifford.md

A quadratic space is a real vector space V with a quadratic form Q(x), e.g. V = R^n with Q as the squared length. The Clifford algebra Cl(V) of a quadratic space is the associative algebra that contains V and satisfies x^2 = Q(x) for all x in V. We're imposing by fiat that the square of a vector should be the quadratic form's value and seeing where it takes us. Treat x^2 = Q(x) as a symbolic rewriting rule that lets you replace x^2 or x x with Q(x) and vice versa whenever x is a vector. Beyond that Cl(V) satisfies the standard axioms of an algebra: it lets you multiply by scalars, it's associative and distributive, but not necessarily commutative.

Remarkably, this is all you need to derive everything about Clifford algebras.

Let me show you how easy it is to bootstrap the theory from nothing.

We know Cl(V) contains a copy of V. Since x^2 = Q(x) for all x, it must also contain a copy of some nonnegative reals.

@giuliohome
giuliohome / PageAjax2.aspx
Created Nov 2, 2018
Calling C# from JavaScript
View PageAjax2.aspx
protected async void Page_Load(object sender, EventArgs e)
{
test++;
if (!Page.IsPostBack)
{
if (Request.Form["method"] == "Test")
{
MyType[] obj = await Test(Request.Form["msg1"], Request.Form["msg2"]);
string json = new JavaScriptSerializer().Serialize(obj);
Response.Write(json);
@giuliohome
giuliohome / FP2TheMax.fs
Last active Aug 18, 2018
F# port of John A De Goes "FP to the max"
View FP2TheMax.fs
open System
type Eff<'Ctx, 'T> = 'Ctx -> 'T
type EffBuilder() =
member __.Return x : Eff<'Ctx,'T> =
fun _ -> x
member __.Bind(f : Eff<'Ctx, 'T>, g : 'T -> Eff<'Ctx, 'S>) : Eff<'Ctx, 'S> =
fun c -> g (f c) c
member __.Zero() : Eff<'Ctx, unit> =
View safetraversal.fs
let rec bfs2robust (fanout: Map<'node, 'node seq> -> 'node -> 'node seq) (tree: Map<'node, 'node seq>) (node: 'node) : 'node seq =
let single = seq [node]
match fanout tree node with
| e when e = Seq.empty -> single
| s -> Seq.fold (fun acc item ->
bfs2robust fanout (tree |> Map.remove node) item
|> Seq.append acc) single s |> Seq.distinct
View gotrees.fs
let rec bfs2 (fanout: Map<'node, 'node seq> -> 'node -> 'node seq) (tree: Map<'node, 'node seq>) (node: 'node) : 'node seq =
let single = seq [node]
match fanout tree node with
| e when e = Seq.empty -> single
| s -> Seq.fold (fun acc item ->
bfs2 fanout tree item
|> Seq.append acc) single s
@giuliohome
giuliohome / BindableTextBlock.cs
Created Aug 7, 2018
TextBloacks with colours !!!
View BindableTextBlock.cs
public class BindableTextBlock : TextBlock
{
public ObservableCollection<Inline> InlineList
{
get { return (ObservableCollection<Inline>)GetValue(InlineListProperty); }
set { SetValue(InlineListProperty, value); }
}
public static readonly DependencyProperty InlineListProperty =
DependencyProperty.Register("InlineList", typeof(ObservableCollection<Inline>), typeof(BindableTextBlock), new UIPropertyMetadata(null, OnPropertyChanged));
View view_v2.xaml
<DataGrid Grid.Column="2" ItemsSource="{Binding SelPayment.eur_invoices}" IsReadOnly="True" AutoGenerateColumns="False"
HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="10,10,10,10" >
<DataGrid.Columns>
<DataGridTextColumn Header="Buy/Sell" Binding="{Binding buysell}" />
<DataGridTextColumn Header="Cpty Name" Binding="{Binding CptyName}" />
<DataGridTextColumn Header="Invoice Nr" Binding="{Binding InvoiceNr}" />
<DataGridTextColumn Header="Amount" Binding="{Binding amount, StringFormat=N}" />
<DataGridTextColumn Header="Curr" Binding="{Binding curr}" />
<DataGridTextColumn Header="Msg" Binding="{Binding ui.msg}" />
</DataGrid.Columns>
@giuliohome
giuliohome / model_v2.fs
Created Aug 2, 2018
Model with composition
View model_v2.fs
type Back2UI() =
inherit SimpleViewModelBase()
let mutable _msg = ""
member this.msg
with get() = _msg
and set value =
_msg <- value
this.OnPropertyChanged(<@ this.msg @>)
type ActivePassive = Active | Passive
@giuliohome
giuliohome / view.xaml
Created Aug 2, 2018
UI binding from an array to a datagrid
View view.xaml
<DataGrid Grid.Column="2" ItemsSource="{Binding SelPayment.eur_invoices}" IsReadOnly="True"
HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="10,10,10,10" >
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