COmmon Business Oriented Language (COBOL) 85 standard was the first language I was taught. Napier University was a feeder into the banking and insurance industries in Edinburgh at the time and they had sizeable COBOL farms. It proved profitable too, as a number of students I knew went to the US to alleviate Y2K bugs in thousands of legacy applications. COBOL had fallen out of favour in US colleges.

I was talking to someone the other day who mentioned that he maintains COBOL legacy applications. Apparently things have gone full circle for the UK, where COBOL is no longer taught so his company outsources to India. I’m not overly surprised COBOL is dying out as an educational tool because as languages go its not like much else – Dijkstra certainly didn’t rate it:

The use of COBOL cripples the mind; its teaching should, therefore, be regarded as a criminal offence.

Who am I to argue with the man who killed the goto statement? Certainly as a language it has issues – the 86 standard wasn’t totally compatible with the previous 74 standard; it has no functions; and it has no pointers. Then again it was in part based around the work of Rear Admiral Grace Hopper, the coolest woman ever in computer science, so it couldn’t be all bad could it? She believed that programming languages in mathematical notation were generally not well understood – COBOL is about as self documenting as it gets. It is a product of its time – for example the first six columns are reserved for sequence numbers, this came about as forms were used to write programs which were in turn converted to punch cards.

An example is the best way to explain this, so I decided to revisit Project Euler’s first problem and code it in COBOL, something I haven’t touched in years. As Rear Admiral Grace Hopper said:

It’s easier to ask for forgiveness than it is to get permission.

Of course we need a compiler, Ubuntu has Open COBOL available:

sudo apt-get install open-cobol

Lets consider the problem again:

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Find the sum of all the multiples of 3 or 5 below 1000.

My solution is to iterate through every number from 1 to 1000, test if it divides by 3 or 5 without a remainder and if so then add it to a counter. In pseudocode:

For counter = 1 to 1000 Step 1
    If counter % 3 = 0 or number % 5 = 0 Then
        total = total + counter
    End If
End For
Display total

But wait – this is COBOL, a language that doesn’t include the word “terse”. So let’s adapt this to a more verbose piece of pseudocode:

For counter = 1 To 1000
    If counter % 3 = 0 Then
        Set flag To TRUE
    End If
    If counter % 5 = 0 Then
        Set flag To TRUE
    End If
    If flag = TRUE Then
        total = total + counter
        Set flag To FALSE
    End If
    Display total
End For

Right, here we go. Its been a long time.  COBOL is organised into divisions, sections, paragraphs, sentences and statements – all are terminated by a period. There are four divisions:

• Identification. Unsurprisingly contains information about the program.
• Environment. This isn’t initially obvious but is concerned with portability – this section allows you to isolate anything that is platform specific. So in theory only the environment division needs changing between platforms.
• Data. This holds all the variables and has four sections – file (file handling); linkage (used with sub-routines); report (for report writers); and the one you almost always need, working-storage (where all your working variables are).
• Procedure. Guess what? Yes this is where the program itself is.

        IDENTIFICATION DIVISION.
        PROGRAM-ID. EULER_PROBLEM_ONE.

Not much explanation required there then. We don’t need an environment division, it doesn’t hurt to populate the division name anyway.

The next division requires a little more explanation. We need a working-storage section but COBOL defines variables using level, name, picture clause and optionally a value.

Picture clauses define a variable’s format. Levels allow data to be grouped, for example if you defined a student as having an ID and a name you might have:

01 student.
    02 identifier          PIC A9(7).
    02 name                PIC A(30).

Level numbers are for the most part arbitrary as long as the lower the number the higher the level, with the exception of 66 (deprecated), 77 (individual elements) and 88 (used to define conditions). Picture clauses can use: 9 (digit); A (letter); X (digit or letter); V (decimal point); S (sign). You can use A(30) rather than typing loads of A’s.

That just leaves us a procedure division. If you have ever coded assembler then you’ll probably find this easier than if you’ve used C. You need to describe every step. The main iteration construct we need from our pseudocode is a For Loop. COBOL has a PERFORM statement, you need to increment your counter yourself:

PERFORM UNTIL counter = 3
    ADD 1 TO counter GIVING counter
END-PERFORM.

A general convention is to use upper-case for reserved words and lower-case for variables. Pretty much all operations follow this command’s format – do something (ADD 1) to something (counter) and store it somewhere (counter).

IF condition1 > condition2 THEN
   STATEMENT
ELSE
   STATEMENT
END-IF.

You can nest if statements (there’s no Else If statement). Its not uncommon to find a lot of legacy code that only uses IF statements, why I don’t know because it has a Case statement called EVALUATE.

That just leaves us assignment:

MOVE value TO variable

Putting it all together, you need variables to Hold temporary values used to calculate answers, I always call it junk:

        IDENTIFICATION DIVISION.
        PROGRAM-ID. EULER_PROBLEM_ONE.

        ENVIRONMENT DIVISION.

        DATA DIVISION.
        WORKING-STORAGE SECTION.
        01 total        PIC 999999     VALUE 0.
        01 counter      PIC 9999       VALUE 1.
        01 junk         PIC 999999     VALUE 0.
        01 flag         PIC 9          VALUE 0.

        PROCEDURE DIVISION.
        PERFORM UNTIL counter = 1000
             COMPUTE junk = FUNCTION MOD (counter, 3)
             IF junk = 0 THEN
                 MOVE 1 TO flag
             END-IF
             COMPUTE junk = FUNCTION MOD (counter, 5)
             IF junk = 0 THEN
                MOVE 1 TO flag
             END-IF
             IF flag = 1 THEN
                ADD counter TO total GIVING total
                MOVE 0 TO flag
             END-IF
             ADD 1 TO counter GIVING counter
        END-PERFORM.
        DISPLAY total.
        STOP RUN.

Remember that indentation is important (despite the code formatting here not wanting to do it) – areas A and B take the first 6 characters so you need to begin in column 7.

Save the file as euler.cob, compile and run it:

cobc -x euler.cob
./euler

Giving the correct answer of 233168, albeit without any frills.

Hold on to your hats...

It took me a while to get this to compile – Open COBOL doesn’t care for the AUTHOR statement in the IDENTIFICATION DIVISION so I removed it.

What this snippet of code doesn’t show us is that larger projects are unbelievably verbose, lines and lines of code. Nor does it cover the hilarity of design using Data Flow Diagrams - queuing for hours to collect printouts from the University’s only 132 column printer.

Well that’s been a fun trip down memory lane, I don’t remember why I started this post.

Now get off my lawn.

Find the greatest product of five consecutive digits in the 1000-digit number.

It then gives a massive number.

My solution is very quick and dirty and makes use of VB.Net’s happiness with jumping between characters, strings and integers. The Val() function treats a character as a value and to make matters easier still, VB Strings can access characters by position. Knowing this, I just iterated through the string multiplying every five consecutive numbers together.

Sub Main()
    Dim beganAt As Date = Now

    Dim hugeNumber As String = _
    "73167176531330624919225119674426574742355349194934" _
    & "96983520312774506326239578318016984801869478851843" _
    & "85861560789112949495459501737958331952853208805511" _
    & "12540698747158523863050715693290963295227443043557" _
    & "66896648950445244523161731856403098711121722383113" _
    & "62229893423380308135336276614282806444486645238749" _
    & "30358907296290491560440772390713810515859307960866" _
    & "70172427121883998797908792274921901699720888093776" _
    & "65727333001053367881220235421809751254540594752243" _
    & "52584907711670556013604839586446706324415722155397" _
    & "53697817977846174064955149290862569321978468622482" _
    & "83972241375657056057490261407972968652414535100474" _
    & "82166370484403199890008895243450658541227588666881" _
    & "16427171479924442928230863465674813919123162824586" _
    & "17866458359124566529476545682848912883142607690042" _
    & "24219022671055626321111109370544217506941658960408" _
    & "07198403850962455444362981230987879927244284909188" _
    & "84580156166097919133875499200524063689912560717606" _
    & "05886116467109405077541002256983155200055935729725" _
    & "71636269561882670428252483600823257530420752963450"

    Dim endAt As Global.System.TimeSpan = Now.Subtract(beganAt)
    Dim took As Integer = endAt.Milliseconds

    Dim answer As Integer
    Dim biggestAnswer As Integer = 0

    For index As Integer = 0 To hugeNumber.Length - 5
        answer = Val(hugeNumber(index)) _
                 * Val(hugeNumber(index + 1)) _
                 * Val(hugeNumber(index + 2)) _
                 * Val(hugeNumber(index + 3)) _
                 * Val(hugeNumber(index + 4))
            If answer > biggestAnswer Then
                biggestAnswer = answer
            End If
        Next

    Console.WriteLine(biggestAnswer.ToString + " in " + took.ToString + "ms.")
    Console.ReadKey()
End Sub

40,824 in 1 ms.

I’ve seen complaints on the module forum that tutors aren’t getting assessments back to quickly enough. The cut off was the 15th (I submitted on the 13th) and it was returned on the 27th, I don’t really see what the problem is.

Nested selection reared its head again but I didn’t lose any marks for it. In every programming module I’ve been picked up for using Else If so I played it safe and used nested If statements. So I was advised to use Else If proving I can’t win!

I enjoy mathematics and programming, my degree modules have revolved around the two, covering Java and VB.Net (its a very Windows centric place the Open University but it’s getting better). I’m in the UK and would like to go back to Edinburgh for family reasons when I leave the services in a couple of years time. Looking at the job boards, there’s a lot of Java contracts in the area.

Has anyone got a job with only open source experience? Does anyone know of any open source projects that are Java based and would be a good starting point to build on the fundamentals? Are there other qualifications or courses that you recommend? What are employers looking for? Does anyone work in a specific field that utilises both maths and programming? Is there a language that is in particular demand or do you find that good experience is more value? What’s a realistic starting salary?

His answer? “Oh no that’s free, it’s bound to be rubbish.”

Strange, I thought he wanted Photoshop free.

I’m keeping the net book – I just replaced the battery on it. I forgot how much care Lithium Ion batteries require. After two journeys to the desert in two years I’ve watched the average life go from around 5 hours under normal use to 1 hour 50 minutes. Last week I noticed it was hitting 50% then telling me I had 8% and needed to charge – so I figured a cell was bad and ordered a new battery (a very reasonable £40 for an after market model). Now I’m relieved to see everything is back up at 5 hours.

I’ve had a couple of days to play with it and get it set up (I’m away on a course next week). First impressions are excellent.

Windows 7 Home Premium comes with Windows Media Centre, which is useful because the TV tuner software that came with my aged Freecom DVB-T is looking rather dated. Windows 7 didn’t recognise the device but luckily I have a copy of Freecom’s BDA driver (which has 32 and 64 bit drivers). I had to go into Device Manager and manually update the drivers.

Running the Windows Experience rating gave me a 4.9. Then I realised that I had no idea what that meant – apparently the index score is based on the lowest score of 5 components rated from 1 to 7.9. I would have expected “Gaming graphics” to have been the bottleneck but actually at 5.9 its not bad – I play a few titles on Steam and ran Bioshock at maximum resolution (1366 x 768) with no problems. The only game I’ve got (which isn’t many) that I have issues with is GTA IV but I have a feeling that’s something to do with DRM or Windows Live for Games.

The HDMI port is very useful, no problems with an HDCP connection between the laptop and my Panasonic TV. Lovefilm and Sky Go on a big screen are much better – my wife isn’t keen on crowding around a laptop screen.

Battery life is pretty good for this specification of laptop, I’m writing this using the “Balanced” setting, with a couple of applications open and downloading a big file over WiFi with the Bluetooth on – it’s at 81% and reading 3 hours 47 minutes.

Updates were a pain, three needed before the touch pad did multi-touch. About 1 Gb all told, with a service packs for Windows 7. That’s where the fun started because the Windows 7 SP failed repeatedly so I downloaded the system update readiness tool - take notice of this advice from Microsoft:

Although the progress bar may appear to stop, the scan is still running and you should not cancel the update.

It certainly appeared to stop. However it did complete and didn’t solve the problem. In the end I downloaded SP1 from Microsoft’s Windows 7 Download Centre (903 MB) and that did install. There’s a lot of forum posts on the Internet about this sort of problem with SP1 and with all the bits and bobs that are installed by Samsung for power management, updates, display and wireless it comes as no big surprise that there are issues with large updates.

Really pretty pleased with this laptop.

It would appear that Samsung uses a custom Master Boot Record (MBR) – so for Grub all is well because you can choose to boot into the recovery partition and away you go. However if you have followed any of the usual guides to removing grub (such as running an XP CD to a recovery console and typing fixmbr) F4 will not launch the restore tool.

System Rescue CD is a great tool to have handy on a USB key. You can, so booting into it run this command:

fdisk /dev/sda

Now pressing “p” should show you that the recovery partition is 1, so type “a” then “2″, “a” then “1″ to make it bootable. Now write the partition table by typing “w” then reboot. At this point you will boot into the recovery manager and be able to recover but the F4 key will not still not be available at boot and of course trying to create a backup will not work either (as Windows will be booted on restart).

Once Samsung Recovery Manager III has loaded up, press Ctrl+Alt+F10 – I had no idea there was a management mode until I read this page (French) but be aware its only available from the recovery partition. It asks for a password – “secos” (without the quotes). Once in management mode, click the “Image” tab and select “Export” then “Select Location”, I used “D:\”. Click “Start” and accept the dialogue box that comes up. This is a backup of the recovery partition.

Once this stage is finished, select the “Tools” tab, insert a spare USB stick and click “Admin Tool USB”. It will format the USB stick and then install some utilities. It takes a couple of minutes. Once finished click the close button in the top right and it’ll ask if the computer should be turned off – say yes.

Boot with the USB key we just made, bringing you to a completely different recovery menu. Click “MBR Fix” and then close the application.

Now when you reboot you’ll notice that the MBR has been repaired and F4 once again boots into Recovery Manager III.

Sure enough, it was a different size and type to the original specification so I refitted a 1 Gb 666MHz stick I had lying around from a previous upgrade and rebooted.

This time we re-flashed, verified and rebooted. Then it kept repeating this cycle so I took off the back panel (use the orange latch visible when the battery is removed) and removed the CMOS battery. After a short pause (30 seconds or so) I put it back and rebooted. This time there was an error message about the CMOS settings (unsurprisingly) and it rebooted.

However this time we got the Compaq BIOS boot screen, so I hit the escape key to enter BIOS. Then hit F9 to load default values, accept it and hit F10 to save values and hey presto the system is back up and running.

Making most, or even all, of the government’s services available online.

Bringing online services together, so that the user does not have to go to different departmental websites for different services.

The text also remarked there are a multitude of formats and making tools to mine this data is complicated.

Hand Rosling has a talk on TED about a dedicated tool to mine such publicly funded data – Gapminder. The software is free to download and the site even offers handouts, lecture plans and interactive presentations. It’s a fascinating talk, highlighting the possibilities of presenting data in new and more accessible ways.

Edit: Here’s Tim Berners Lee discussing open data availability a year after requesting it.