Sudhir Murthy

Saturday 15 November 2008

Tricolor on the moon!!

The probe, painted with the Indian flag, touched down at 2034 (1504 GMT) Friday the 14th of November 2008, the Indian Space Research Organisation (ISRO) said.

India has become the fourth nation to join the stuff-on-the-Moon club, after the Chandrayaan-1 spacecraft in lunar orbit successfully launched an impact probe at the lunar surface. The 35-kg impactor was blazoned with the Indian flag.

Mission Objectives

Carry out high resolution mapping of topographic features in 3D, distribution of various minerals and elemental chemical species including radioactive nuclides covering the entire lunar surface using a set of remote sensing payloads. The new set of data would help in unravelling mysteries about the origin and evolution of solar system in general and that of the moon in particular.

Realize the mission goal of harnessing the science payloads, lunar craft and the launch vehicle with suitable ground support system including DSN station, integration and testing, launching and achieving lunar orbit of ~100 km, in-orbit operation of experiments, communication/telecommand, telemetry data reception, quick look data and archival for scientific utilization by identified group of scientists.

Chandrayaan-1 spacecraft undergoing pre-launch tests

Moon Impact Probe

PSLV 11 Assembled and ready to go at sriharikota.

PSLV-C11 at Vehicle Assembly Building

INDIA SHOOTS TO THE MOON!. Photo of PSLV-C11 liftoff launching the Chandrayaan-1. 22 Oct 2008

MERA BHARAT MAHAAAAN! JAI HIND!

Chandrayaan - Payloads

Chandrayaan - Photo Gallery

Tricolor on the moon

Chandrayaan-1

Tuesday 11 November 2008

XHTML - A very simple primer.

XHTML is a reformulation of HTML in XML. XML is mainly made up of generic tags which can be used to define data. XHTML is derived from XML or putting it the other way, XML is the base for XHTML. XHTML is also very similar to HTML 4.1.

According to W3Schools,

“XHTML is a combination of HTML and XML (EXtensible Markup Language). XHTML consists of all the elements in HTML 4.01, combined with the strict syntax of XML.”

Tips to be XHTML 1.0 compliant

1. Start writing your tags and attribute names in lower cases

for eg. <BODY> - is wrong

<body> - is correct.

<table WIDTH = “100%”> – is wrong

<table width = “100%” > – is correct

2. Always close your tags.

for eg. <p> this is a paragraph – is wrong

<p> this is a paragraph </p> – is correct

Be particularly aware when using tags like <img> <br> which do have a self closing tag in HTML 4.0,

These need to have a self-closing tag which is described as below.

<img src=”c:\\images\\alive.png”> – is wrong

<img src=”c:\\images\\alive.png” /> – is correct.

<br> – is wrong

<br/> – is correct

- is wrong

<ul>
<li>Coffee</li>
<li>Tea
    <ul>
      <li>Black tea</li>
      <li>Green tea</li>
    </ul>
</li>
<li>Milk</li>
</ul>

- is correct

4. XHTML documents MUST have a root element - <html>

The document structure should look like

5. Attribute values MUST be in quotes

</div> – is wrong

<div id=”header”>

</div> – is correct

<table width=”100%”> - is correct.

<table width=100%> - is wrong.

6. Always add a <!DOCTYPE> declaration to you page.

A DOCTYPE gives the browser information about the kind of HTML it expects.

The DOCTYPE declaration is always the first line in an XHTML document.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title> xhtml document</title>
</head>
<body>
<p> welcome to xhtml standards</p>
</body>
</html>

The XHTML DTD (Document type definition) defines the syntax of the XHTML markup.

XHTML 1.0 Strict

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

XHTML 1.0 Transitional

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

Use the transitional DOCTYPE for valid markup and pages which render the same in all major browsers.

XHTML 1.0 Frameset

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">

Use the frameset DOCTYPE when you want to use HTML frames.

How w3schools was converted to xhtml

Useful Links

The XHTML 1.0 markup language (Second Edition) - http://www.w3.org/TR/xhtml1/

The XHTML Validator - http://validator.w3.org/

W3School’s XHTML Tutorial - http://www.w3schools.com/xhtml/

Tuesday 4 November 2008

Mark Russinovich: Inside Windows 7

http://channel9.msdn.com/shows/Going+Deep/Mark-Russinovich-Inside-Windows-7/

Windows 7 Can scale upto 256 processors. whoohoo!!

Monday 3 November 2008

The Numerati – Stephan Baker

They’ve Got Your Number

Maybe you’re the kind of person who doesn’t believe that the kind of person you are can be deduced by an algorithm and expressed through shorthand categorizations like “urban youth” or “hearth keeper.”

Maybe I’d agree with you, and maybe we’re right. But the kind of people — “crack mathematicians, computer scientists and engineers” — whom Stephen Baker writes about in “The Numerati” clearly see things differently. NYTimes Article

Wednesday 22 October 2008

A Simple RSS Reader in WPF

I present here, a simple Rss reader written almost entirely in XAML. I personally find WPF Data binding powerful and exciting to work with.

To start with, i've used the XmlDataProvider class to hook up the source to an rss feed and set it's XPath property to "rss/channel/item", so that i get all items in the channel.

The layout is an utterly simple dockpanel which has a stackpanel docked to the top, a status bar docked to the bottom and a grid which fills up the remaining space.

The databinding is self explanatory with the following code.,However an important thing to note is that the <Textbox> which has the rss feed link is binded to the source directly. The 'UpdateSourceTrigger' property is by default set to LostFocus(). I've changed it to 'PropertyChanged', so that when a user enters an rss feed, the bindings get updated. Also notice that 'BindsDirectlyToSource' is set to True. Another interesting feature is the Master-Detail binding. Notice that between Line numbers 53-63. The listbox's selection is binded to description and link which are textblocks inside a stack panel. Now, when the listbox gets focus, we bind the frame's source to the uri in the texbox.

I've added some styles to the listbox aswell. all of which could be found in the source code. This surely is very simple and yet a foundation to write a powerful rss reader in wpf. :)

We could add more rss feeds, write value converters, validation rules etc. as required.

Window1.xaml

        1: <Window x:Class="RssReader.Window1"

       2:     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

       3:     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

       4:     Title="RssReader" Height="600" Width="800">

       5:     

       6:     <Window.Resources>

       7:     <XmlDataProvider x:Key="rssdata"

       8:                      Source="http://newsrss.bbc.co.uk/rss/newsonline_uk_edition/front_page/rss.xml"

       9:                      XPath="rss/channel/item"/>

        

    </Window.Resources>

    

    <DockPanel   DataContext="{Binding Source={StaticResource rssdata}}">

        <StackPanel DockPanel.Dock="Top"

                    TextElement.FontWeight="Bold" Background="Gray">

        

            <TextBlock Text="{Binding XPath=./../title}"

                    FontSize="20" Margin="10 10 10 0"/>

            

            <TextBlock Text="{Binding XPath=./../description}"

                    FontSize="10" FontWeight="Normal" Margin="10 0"/>

            

            <TextBox Margin="5" Text="{Binding Source={StaticResource rssdata},                             

                                BindsDirectlyToSource=True,

                                Path=Source,

                                UpdateSourceTrigger=PropertyChanged}"/>

        </StackPanel>

  

        <StatusBar DockPanel.Dock="Bottom">

            <StatusBarItem Content="{Binding XPath=title}"/>

            <Separator/>

            <StatusBarItem Content="{Binding XPath=pubDate}"/>

        </StatusBar>

  

        <Grid>

            <Grid.ColumnDefinitions>

                <ColumnDefinition Width="25*"/>

                <ColumnDefinition Width="75*"/>

                <ColumnDefinition/>

            </Grid.ColumnDefinitions>

           

            <ListBox Grid.Column="0" IsSynchronizedWithCurrentItem="True"                     

                     ItemsSource="{Binding}" DisplayMemberPath="title"

                     Style="{StaticResource ListBoxHand}"/>

            <GridSplitter/>

            

            <Grid Grid.Column="1">

                <Grid.RowDefinitions>

                    <RowDefinition Height="Auto"> </RowDefinition>

                    <RowDefinition Height="85*"> </RowDefinition>

                </Grid.RowDefinitions>

  

                <ListBox x:Name="selection" Grid.Row="0" IsSynchronizedWithCurrentItem="True"                         

                         Style="{StaticResource SimpleListBox}"

                         VerticalAlignment="Stretch"

                         GotFocus="selection_GotFocus">

                             

                    <StackPanel>

                            <TextBlock Text="{Binding XPath=description}" />

                            <TextBlock x:Name="txtlink" Text="{Binding XPath=link}"/>

                        </StackPanel>

                </ListBox>

                    <Frame x:Name="Explorer" Grid.Row="1"/>

            </Grid>

        </Grid>

  

      </DockPanel>

    </Window>



Window1.xaml.cs

       1: private void selection_GotFocus(object sender, RoutedEventArgs e) {

       2:   Uri uri = new Uri(this.txtlink.Text.ToString());

       3:   this.Explorer.Source = uri;

       4: }

       5:

Screenie

C0d3 : here