tireetoo

2011 Scavenger Hunt

2011-10-03T12:52:00.000-07:00

Collect and bring back...

Small black stone.
Small white stone.
Spiky leaf.
Round leaf.
Piece of moss.
Leaf with 5 spikes.
Pine cone.
Berry - don't eat it.
Y shaped twig.
Small pink stone.
Piece of bark.
Daisy.

A drawing of...

Castle
Tree
Party

There are extra points available for the best drawings.

Quiz...

Birds makes nests in a _____?
I have lots of arms but am not a person?
The bear in jungle book is _____?
Who painted the mona lisa?
The Lion in 'the lion, the witch and the wardrobe' is called?

Computer Science Primer 1 - bits and bytes

2011-09-12T15:43:00.000-07:00

Introduction

In a recent job interview my basic CS knowledge was found lacking. To be honest, I have never been fully comfortable with the building blocks of computer programs. So what follows are a couple of back to basics primers in the fundamentals of computer science. I'll be using these posts to refresh my knowledge.

Data and Memory Storage - bits and bytes

^[1]Most computers use the byte as a unit of data - and this byte most commonly consists of 8 bits.

Storage of Bytes

Each bit is a binary value (0 or 1, false or true) - with 8 bits (one byte) being able to represent 256 different values - 0 upto 255. This is as a consequence of counting in base 2 - it's base 2 because every bit can have only 2 values.
e.g.

Bits	Value
00000000	0
00000001	1
00000010	2
00000011	3
00000100	4
00001000	8
00010000	16
10000000	128
11111111	255

Operations on Bits

^[2]

The storage of data in bits can lead to some unusual behaviors. Bits can be flipped (0 to 1 or 1 to 0) or shifted (moved along) to produce other values.

Operations are NOT which flips all the bits, AND which combines two binary numbers and for each pair of bits results in 1 if both bits are 1 otherwise 0, OR which results in 1 if either or both pair of bits are 1 and 0 if they are both 0 and XOR which results in 1 if both values are different and 0 if they are the same.

Shifting of bits results in new values. A left shift by n spaces is equivalent to multiplying by 2^n - because of the binary (base 2) representation mentioned earlier. Likewise a right shift of n spaces is equivalent to dividing by 2^n - with a rounding down - as the rightmost bit is lost off the end of the byte.

e.g.

Bits	Value	Operation	New Bits	New Value
00000000	0	flipped	11111111	255
00000001	1	left shift	00000010	2
00000100	4	left shift	00001000	8
00010001	17	right shift	00001000	8

Interesting Stuff

A number XOR'd with itself results in 0.
If you take 0 and flip all the bits (NOT operator) then you will get the largest number which can be stored in that value. e.g. with a java int (4 bytes) 0 combined with the operator NOT becomes 2,147,483,647 (2^31 - 1).
All kinds of interesting hacks: http://graphics.stanford.edu/~seander/bithacks.html
However please don't sprinkle your code with clever hacks as your code should describe the intent of the program and not attempt to hook into any potential compiler/JVM/hardware implementation. This is discussed in http://stackoverflow.com/questions/1168451/is-shifting-bits-faster-than-multiplying-and-dividing-in-java-net and other places and 2^32-1 other places :-).

References

sync contacts in old nokia phone - it works!

2010-10-28T14:51:00.000-07:00

http://www.google.com/support/mobile/bin/answer.py?hl=en&answer=98230

maths primer 1 - adding, subtracting, rounding and the number line

2009-12-13T10:05:00.001-08:00

Learning to add and subtract numbers can be awkward but a few simple rules can help. Conceptually the number line is useful.

When adding numbers we want to know - how big is the block when we put these two smaller blocks together.

When subtracting numbers we want to know - how big is the gap between these two numbers.

And when dealing with numbers that are not multiples of 10 it helps to round the numbers to the nearest 10 and then think about whether the exact (original) numbers shrink or grow the block (when adding) or the gap (when subtracting).

how to fill out the vat 100 form

2009-09-16T14:36:00.000-07:00

1. Are you flat rate registered? If yes then find out your flat rate. As an IT contractor the flat rate is currently 13% and the full VAT rate is 17.5%.

2. Boxes 1, 3 and 5 are the VAT payable. e.g 13% of gross revenues for the period.

3. Box 6 is just the gross revenue.

4. Sign and date form.

5. Write out cheque. Put in envelope with form. Stick stamp to envelope.

6. Remember to post. Dont leave next to fridge under chidrens pictures, adverts for local tree chopers, old post etc.

7. Repeat every 3 months.

8. Or make online payment to 08 32 00 - 11963155 - HMRC VAT using your VAT registration number as the payment reference.

Porch - Floating

2009-02-15T14:11:00.000-08:00

rails deployment

2009-01-31T13:04:00.000-08:00

It has been lovely this evening.
> cap deploy (then remember the password for the shell on the remote server, and it is job done)
Back to tomb raider and my beer.

In the background cap has...

checked out a snapshot of the code from svn
sorted out file permissions
cleanedup but log/pid files etc. created some other required dirs (I wont go into all details)
touched all images, css and javascript files to prevent browser caching of old versions
created a new symbolic link from current to the new release
told phusion_passenger to restart the app

All those 6 steps in two simple words - I haven't deployed for over a month, have upgraded the rails and gems but still it works.

2009-01-24T04:33:00.000-08:00

2009-01-24T04:32:00.000-08:00

Pie King

2008-03-11T15:50:00.000-07:00

They are the best. Kings of pies. Masters of the NE diet - steak bake and a yum yum.

Where's me bus?

2008-03-11T15:46:00.000-07:00

I cant see the bus. Should have been here 10 minutes before. Oh yes I remember it is stuck in a queue of cars somewhere down the road. This was the view from the bus stop in Colinton this morning.

Fortunately the sun was shining, me book was open and the chat was good - it should have been as the queue of people was 40m down the road.

Craiglockhart Ave in the morning

2008-03-07T13:23:00.000-08:00

I love cycling across this road. Great fumes. Great view. What you see here extends in both directions for quite some distance and is not unusual. Just a normal day in Edinburgh, a road being used as a car park. Notice the large BMW in the middle parked diagonally right across the 'do not block' junction area - who cares, obviously not the tin box driver.

Agile Resources

2007-11-29T03:33:00.000-08:00

Some good reads about Agile processes...

http://www.scrum.com.au/2007/11/18/scrum--use-more-paper
http://www.threeriversinstitute.org/Toe%20Dipping.pdf

red sofa

2007-11-11T14:27:00.000-08:00

not very exciting. its a sofa

make it faster baby

2007-10-03T15:42:00.000-07:00

So its Autumn 2007 and the Mosmorran flame is burning brightly, the nights have fairly drawn in and its time to start coding. I've a nifty killer app to build will it be Rails, Wicket, GWT or SpringWF? I don't know the answer. I can tell you that I know the backend and I know the html but I'm not so sure about the Javascript stuff, so all that leans me towards GWT or Wicket.

Lets revisit this question in 6 months time and see where we are. Its like standing on a Windscale beach, lonely and all the sands are shifting but at least the grains glow and your neighbours have 3 eyes.

howzatt

2007-09-26T15:00:00.000-07:00

Your out.
Wicket is lovely.
As shown by this...
http://blog.platinumsolutions.com/Wicket-Tutorial
I could not write it better myself.

Yesterday or Tomorrow

2007-09-06T14:38:00.000-07:00

Thinking about days and nights and the good old Java 'when are we now?' classes Date and Calendar. If I want to know if something is earlier than today...



public boolean isBeforeToday(Date date) {
  Calendar cal = Calendar.getInstance();
  cal.set(Calendar.HOUR, 0);
  cal.set(Calendar.MINUTE, 0);
  cal.set(Calendar.SECOND, 0);
  cal.set(Calendar.MILLISECOND, 0);

  Date startOfToday = cal.getTime();
  return date.before(startOfToday);
}

It feels pretty clunky. Likewise for after today...


public boolean isAfterToday(Date date) {
   Calendar cal = Calendar.getInstance();
   cal.set(Calendar.HOUR, 23);
   cal.set(Calendar.MINUTE, 59);
   cal.set(Calendar.SECOND, 59);
   cal.set(Calendar.MILLISECOND, 999);

   Date endOfToday = cal.getTime();
   return date.after(endOfToday);
}

What if I want to know if a date is within the day before today (otherwise known as yesterday)...


public boolean isYesterday(Date date) {
   // get a calendar for yesterday
   Calendar yesterday = Calendar.getInstance();
   yesterday.add(Calendar.DAY_OF_YEAR, -1);

   // and one for the test date
   Calendar cal = Calendar.getInstance();
   cal.setTime(date);

   // true if year and day of year are equal to yesterday
   return (yesterday.get(Calendar.YEAR) == cal.get(Calendar.YEAR))
     && (yesterday.get(Calendar.DAY_OF_YEAR) == cal
     .get(Calendar.DAY_OF_YEAR));
}

Long winded? So I got to thinking about some possible short cuts and wondered what the following could give us...


public long getOrdinalDayForDate(Date date) {
  final long MILLISECS_IN_DAY = 1000 * 60 * 60 * 24;
  return date.getTime() / MILLISECS_IN_DAY;
}

By giving each date an index, day number from the first day of 1970, we can have...


public boolean isToday(Date date) {
  return getOrdinalDayForDate(date) == getOrdinalDayForDate(new Date());
}
    
public boolean isYesterday(Date date) {
  return getOrdinalDayForDate(date) == (getOrdinalDayForDate(new Date())-1);
}
    
public boolean isTomorrow(Date date) {
  return getOrdinalDayForDate(date) == (getOrdinalDayForDate(new Date())+1);
}

Am I on the right track with this?

thomas coal depot - its great

2007-06-23T12:29:00.000-07:00

Has only one motor and 3 Tops that change over as the engine runs around the track.
12 piece track with Thomas, Percy, Terrence and assorted towers. Once the trains and loader are in position set the motor on the tracks and sit back as Percy delivers a load of coal from the dispenser and dumps it near the fillling tower, reverses and changes the motor with Thomas who changes motor with Terrence.
Then Terrence the Digger scoops up the coal Percy dumped and puts it in the loader, that fills Thomas. Terrence then changes motor with Thomas. He does this cool 3-point turn and reverses up the hill to dump the coal in the dispenser then goes down, another cool turn and he changes with Percy to start all over again!

01254274944

2007-05-28T04:26:00.000-07:00

Just been called by this number [01254274944] on my mobile. And taken straight to an answering machine. Dont know who they are. But sounds a bit like a scam. Put the phone down before all my credits are eaten.

Blue tiles...

2007-01-22T03:35:00.000-08:00

35 blue tiles

ms sql basic client

2006-12-20T02:39:00.000-08:00

osql -Usa -P -S

blackcurrant flavoured apple jam - yum yum

2006-07-24T05:34:00.000-07:00

I thought that the co-op cared about food standards, food processing, food transparency and
general food care.

I have just bought a pack of '6 Assorted Jam Tarts' from the co-op store in Leith. There were many packs reduced in price as they are close to the sell-by date. Not surprising really.

Whose idea was it to use apple jam, flavoured and coloured to masquerade as blackcurrant
jam? Did you expect blackcurrant flavoured apple jam to appeal to your customers more than
standard blackcurrant jam? Or was blackcurrant jam vetoed for some financial reason? Does blackcurrant jam cost more than apple jam?

This product cuts through the marketing fog and demostrates the true supermarket and industrial food credentials of the co-op.

thunderbird mailto support causing me grief

2006-07-21T03:46:00.000-07:00

When a browser has a mailto: link it is failing to interact with Thunderbird 1.5.0.4, I get the error...

Thunderbird is already running, but is not responding. To open a new window, you must first close the existing Thunderbird process, or restart your system.

This also stops picassa from generating an email containing pics. Doesnt look good.
Sort if out Chunderbird.

2006-03-06T09:46:00.000-08:00

Just trying to use maven (maven.apache.org) and Im not convinced, even if they do say its the new improved maven2 thing.

When running mvn test WHY does it log all log4j at the DEBUG level so the stdout is flooded with text. Tests failed 3 out of 623 but you'll be lucky to find the errors in all the dross output to the screen.

How do I get a build number into the jar manifest or a version.properties file? Not at all clear in the Getting Started guide.

I think we might just stay with ANT - its simple.

real wood office desk

2006-03-05T12:13:00.000-08:00

A real wood office desk bought in the East Lothian (just East of Musselburgh) scrap yard about 4 years ago. I have half sanded the desk. But now we need the room it lives in for a baby.

Stamped inside the drawer is 'This is an Abbess D103 product'.

freecycle - sony SLV-E710

2005-11-30T14:00:00.000-08:00

Bought last year from a charity shop and used for 6mnths. We dont use it now. I think we stopped due to not working but I cant really remember. However it is a good solid machine.

freecycle four - the coal bunker

2005-10-09T13:41:00.000-07:00

One used coal bunker, circa 1960. Not needed by me anymore. Would anyone like it.?

freecycle three

2005-09-11T13:26:00.000-07:00

Here is a very simple tv stand (from a toshiba 21 inch telly) made from plastic and metal.

freecycle two

2005-09-11T13:23:00.000-07:00

And here we have the ikea (not again) black ash coffee table.

stuff for freecycle

2005-09-11T13:11:00.000-07:00

Here we have the ikea sink plumbing set (minus one item from the bag) - bought last year and the plumber did not want to use the ikea bits. Will be going into the bin if no-one wants them

Loch Rannoch

2005-08-11T05:05:00.000-07:00

Great Bikes: YES
Hills: YES
Accidents: YES
Cool Camping: YES
Midges: YES YES YES
There was nothing wrong with the Brompton, we had just lost another rider (due to getting wheel trapped in hole and going over handlebars) and had 5 bikes and 4 riders. The brompton was very good at being pushed along by its seat.

halfway there

2005-07-22T02:33:00.000-07:00

Thought I had better get around to publishing the green machine part way through its assembly. Thanks to the bike station for the frame, thanks to Hendersons metal sprayers for the colour and thanks to Newhaven Bike Shop for removing the old headset.

smiling practise

2005-07-22T02:27:00.000-07:00

Always good to test your smiling ability. But not the false kind. Just the really big cheshire cat ear to ear grin. :-)

how low

2005-07-22T02:19:00.000-07:00

Diego Garcia, Avoidable Greed Induced Oil Wars and use of ClusterBombs+Napalm+Uranium, Ignoring Famine, Ignoring 3m+ dead in the Congo, Actively supporting nasty regimes. How much injustice can people stomach?
This stuff seems to have gotten me a bit down this week. I think general fallout from the highs of meeting so many positive people at the G8 protests and imagining that another way is possible.
Better get back to work for the stock market quoted TNC. :-{

negative vibes

2005-03-10T09:29:00.000-08:00

User story...
whats that?
sounds a bit american
just more jargon
is it another name for a feature
change for changes sake
but we are not doing user stories we have just renamed chunks of code
we dont have any users

The teams thoughts on User Stories [XP] Any movement to a more XP centric development pattern may take a little time.

blog!

2005-01-06T06:05:00.000-08:00

I have just remembered that I have this blog!
Hmmm.
Should I bother.

cruisecontrol - same status as subversion?

2004-10-01T09:05:00.000-07:00

Not that easy to get going.
1. Some issues with how to start the thing. The docs mention somthing about java -jar cruisecontrol.jar but that is not nearly enough as you need to make sure that you have all the CC dependancies included in the classpath. So you might as well use the cruisecontrol.bat file

2. Trouble with the temp dir location. Maybe better to have a standard location built in.

3. Tightly built against a certain version of ANT.

4. Use of JSP and XSL in the web ui. Adds complexity.

Apart from that it is quite clever.

darker still

2004-10-01T06:16:00.000-07:00

Woke at 5am and its still dark out there. Back to sleep and awake again at 6.45 - it is lighter now.

subversion - has it arrived?

2004-10-01T06:12:00.000-07:00

No tasks shipped with ANT 1.6.2 release yet so I dont think it is ready for the big time. Built in ANT support has to be a measure of its readiness.

svnant - needs some dodgy jni libraries - never a good sign.
jsvn - where is the documentation?

Back to VSS I guess. But I dont want to.

the beginning

2004-09-07T13:28:00.000-07:00

And there was no light. Well at 8pm this evening there was no light as the sun had gone down. Winter is comin. If you like to know about the lights going out then as usual trouble maker Monbiot hits the spot with (http://www.monbiot.com/archives/2004/08/10/goodbye-kind-world-/).

Took new home built speed machine out for a quick evening spin on new rock hard pumped up tyres (thanks Murray). It surely fies. I predict time to work of 35mins on the new route but we will test that later

That will do for now. Pics of the speed machine later.