Thoughts of a geek

20 May 2013

7/7: The Rainbow Connection

Filed under: Me, The Blog Roll — qwandor @ 1:07 am

(Day 7 of an effort to blog every day for a week, alongside a bunch of blogging friends.)

The Rainbow Connection has been going through my head all day. Humming the tune to myself in time to my steps as I walk down the street.

Went to church in the morning as usual, the 11:30 am service. Matthew was there, with a friend of his who is visiting from NZ for a couple of weeks. The sermon was about spiritual gifts, among other things, from I Corinthians 12:1-11. I disagreed with some of the implications made by Rico Tice; it is a pity that there is never much of an opportunity for discussion. Oh that I could find the perfect church!

Afterwards I walked down Oxford Street and through Hyde Park and Kensington Gardens to a pub in Kensington for lunch to celebrate Fi‘s birthday. She was a bit late to arrive (for the fairly reasonable excuse that it was her first day getting around without a wheelchair, just crutches), but fortunately I was able to find two of her friends who were there already. In the end 6 of us got there before her, to much amusement. ‘Twas good to catch up a bit, and chat to a few nice people, and the food was good too. I had a tasty beef and bacon burger.

Afterwards I caught a bus down to Clapham Junction to catch the end of an afternoon swing-dancing fundraiser a friend was running for a movie she is going to be involved in making. I got there in time for a bit of dancing, said friend singing a couple of songs (she has a great voice, I had not heard her sing before; she has a number of videos on Youtube though, such as this one), a duo on ukelele and banjo playing a couple of songs for everyone to sing along to, an amusing short act by two Victorian time-travelers, and then a band playing a great set for us to dance to. The band was more rockabilly than swing, but great fun and very energetic. They did throw in one more bluesy tune in the middle which was nice. It has been much to long since I have done any blues dancing, I really need to get back into that! There were some tasty homemade cakes on sale too; I had a bit of ginger cake and a macaroon. It was a good afternoon, but exhausting.

Afterwards I bussed home, had some ryebread with cheese and marmite, did a load of washing, and called my mum to walk her through the process of moving her new harddrive from her computer to my old computer (which is marginally newer and hopefully less noisy, and had been sitting in the basement unused for the past 3 years). The only complication was that apparently for some reason my computer names its Ethernet interface eth1 rather than eth0, so we needed to update a config file accordingly. And GRUB is giving an error message ‘out of disk’ on a cold boot, which goes away after resetting. Rather odd, but at least there is a workaround for now. Has anyone come across anything similar before? This is GRUB 2, and it is booting from a 1 TB SATA drive. What little information I can find online seems to suggest it might be something to do with the BIOS not liking large drives, but that does not explain why it works on the second try.

Watched the final episode of this series of Doctor Who on iPlayer. It was alright. I have not been impressed with this latest series on the whole, especially the second half. Hopefully they will find a new writer to replace Steven Moffat sometime soon. He did start off well, but seems to have run out of good ideas.

Bedtime.

19 May 2013

6/7: No tea

Filed under: Me, The Blog Roll — qwandor @ 1:00 am

(Day 6 of an effort to blog every day for a week, alongside a bunch of blogging friends.)

I was going to be making muffins with a friend this morning, but sadly that fell through. I slept instead. Finally got up at about 11:45 am. That is the most I have slept in in a long time. Perhaps needed though, I had not been getting enough sleep lately.

Did not do anything terribly productive. Bought groceries for Tuesday’s dinner-party. Ate the left-over pizza in the fridge from Monday’s dinner which I had forgotten about; it was still mostly edible, if a little stale (or soggy, in one part. That was weird.) Washed some clothes and my towel. Did not quite get around to doing the vacuuming I had planned to do. Made a smoothie, and the blender leaked.

In the evening I went out to a contra up in St. Albans. The caller was excellent, and the band were decent, but it was almost all old people which was a pity. My attempts at getting people from London to come along were not very successful, only Gareth came. Still, mostly enjoyable. The train back stopped at Blackfriars so I Boris-biked from there, and got home some time after midnight.

I wonder when I will watch tonight’s Doctor Who episode. Certainly not tonight, it being 12:55 am, and probably not tomorrow night either. Maybe Monday.

Things to be done: vacuuming, selecting and cropping a passport photo, working out how tall I am and what my eye colour is called, sleeping, writing a blog post about dwarves, finding a new time for muffin-making, thinking about plays to go to, organising travel plans for the summer. What else have I forgotten?

18 May 2013

5/7: Eurovision is not terribly exciting

Filed under: Me, The Blog Roll — qwandor @ 12:32 am

(Day 5 of an effort to blog every day for a week, alongside a bunch of blogging friends.)

Friday! Busy day at work, as it has been since I got back.

This week’s TGIF (our Friday afternoon drinks) were Eurovision themed, which meant various Eurovision songs playing in the background, flags hanging from the ceiling, and food (supposedly) from various different European countries.

I left to have a nap at home before going up, but I only ended up with about 10 minutes to nap in the end. Went to an English ceilidh I sometimes go to, which happens once a month at Cecil Sharp House, the home of the English Folk Dance and Song Society up in Camden Town. For some reason there were not many people there this month, only about half to a third of the usual number. And only a couple of people I knew. Still, decent fun. Decent band, good caller, younger than most of the usual ones. Nothing particularly out of the ordinary. I do tend to prefer the contra a lot more these days.

Bedtime soon, I just need to send a few messages organising next week’s dinner party.

Doctor Who finale tomorrow! And the St. Albans contra, if I go to that. And maybe muffins in the morning.

17 May 2013

4/7: No blues

Filed under: Me, The Blog Roll — qwandor @ 10:18 am

(Day 4 of an effort to blog every day for a week, alongside a bunch of blogging friends.)

Nothing terribly exciting. Let’s see.

Oh, the weather was relatively nice today. Still a bit cold, but nice and clear. I think this morning was my first time for the year eating breakfast outside in the sun on the balcony. I ate lunch outside as well. The weather not being so warm did have the advantage that there were still seats available outside.

Food Revolution Week continues at work. This afternoon there was another cooking demo, with four different types of stir fries based on chicken, tofu, beef, and some sort of seafood, with all sorts of vegetables, rice, and various different sorts of noodles. They were all tasty (except for the seafood, which I do not like). A fair bit of work to do.

My bike ride home is quite scenic, if I can take the time to look up from the road. On my 15 minute ride, at around 9:30 pm this evening, I could see the MI6 building, Westminster Palace, the London Eye, the Shard and the Imperial War Museum, all nicely lit up.

No blues dancing this evening sadly, as the night I usually go to was moved to Wednesday this week, so I could not go.

Starting to organise having friends over for dinner next week sometime. And making muffins with other friends. I got some photos for my passport today, so I need to pick one and crop it, then measure my height so I can put in the online application at some point soon. And I still need to sort out my Boris bike account, which for some reason I cannot login online to update my debit card details.

Perhaps I will get to bed before midnight tonight. (Hah.)

16 May 2013

3/7: Rosemary, lemon, and the GRand Unified Bootloader

Filed under: Me, The Blog Roll — qwandor @ 11:21 am

(Day 3 of an effort to blog every day for a week, alongside a bunch of blogging friends.)

There was a cooking demo at work this afternoon as part of Food Revolution Week. Apparently it is only a day in the outside world, but all week at Google. Anyway, some celebrity-ish chef showed us how to cook 5 recipes from her cookbook, and we got to try some of the results. The only one I am likely to make, if I get the details, was a dessert made from double cream, lemon juice, sugar and rosemary, and served in shot glasses with a raspberry on top. A quick search suggests that this is called a posset. The rosemary seemed like a strange addition, but it actually worked really well, adding an interesting flavour. I might have to try it myself sometime.

I watched the first part of the Google I/O keynote at work before heading to Springboard, a course I am doing at church on Wednesday evenings. Biking through Hyde Park in the light is really quite a different experience than when it is dark and rainy. Last week was my first time doing so, not having biked that route in the previous month (since BST started) as I was away in New Zealand. The ride home was a bit slow due to various roadworks, and trucks stopping in bad places.

I spent the rest of the evening in a G+ Hangout with my mum again, this time trying to fix bootloader issues so she could boot of her new hard drive successfully. We got there in the end, but it would have been much quicker if I had been in the same room; remotely diagnosing problems when I cannot very easily see what is happening or type directly is rather fiddly.

And now it is too late again. Goodnight.

15 May 2013

2/7: Serial ATA

Filed under: Me, The Blog Roll — qwandor @ 11:58 am

(Day 2 of an effort to blog every day for a week, alongside a bunch of blogging friends.)

Work much the same as yesterday, nothing particularly out of the ordinary. Making some progress.

Flatmates did not have any of the leftover dessert from last night in the end. Nor did I.

Spent most of the evening in a G+ hangout with my mum back in Wellington walking her through how to install her new SATA hard drive in her computer, copy the data from the old IDE drive across, so that she can then put the new drive into my old desktop (which is slightly better than hers, and hopefully significantly less noisy). Slightly tricky explaining how to do everything without actually being there, but she did well. I am proud of my mum. (-:

Did not get to catch up with Rachel after all, sadly.

Watched last Saturday’s episode of Doctor Who. It had some interesting bits, but I am still not very impressed with this season. Oh well. The Doctor Who prom this summer should be fun though! Hopefully I can get a good group of people together with whom to queue. I should see what plays are on at the Globe this summer too, that is always fun.

Setting up a Facebook page to promote the monthly contra dance in London. Not quite ready yet.

I really should be trying to sleep, it is almost 1:00 am.

14 May 2013

1/7: Desserts came very quickly after agriculture

Filed under: Me, The Blog Roll — Tags: — qwandor @ 11:35 am

(Day 1 of an effort to blog every day for a week, alongside a bunch of blogging friends.)

Work was busy in a stop-start way. We have a launch coming up soon of something I have been working on for some time so need to get everything ready, but I am often blocked on other people. This has been more or less my usual state of being for some time though, so nothing is all that new.

I need to get on with applying for a new passport soon, which will require getting a passport photo taken. And measuring my height. I have vague memories of having a tape measure somewhere. I also need to help my mum back up her computer, and copy everything on her old small IDE hard drive to a new bigger SATA hard drive, so she can then migrate to my old desktop (which is at least slightly newer than her current machine, and hopefully noticeably quieter). Attempts to catch up with Rachel in the weekend failed, so need to find a time to see her before she leaves on Wednesday. Hmm, what am I forgetting?

As usual, not much time to think.

Had Aga, Luca and Luca’s flatmate Emily over for dinner this evening, my first London dinner party since before Easter. Aga is a Googler, Luca is a blues dancing friend. There was some confusion about the meaning of the expression “+1″. They all seemed to enjoy trying feijoas. We made a couple of pizzas: one vegetable pizza with capsicum, mushroom and fresh basil, and one with sausages, salami, pineapple and more basil. I had forgotten that salami contains pork, and that they were pork sausages (Luca does not eat pork, sadly). I did not get the ratio quite right for the dough (or something) and the texture was completely wrong at first, but I managed to fix it passably in the end. They were both pretty tasty, especially the basil. Fresh basil always smells amazing too. Oh, and we had smoothies too; banana, peach, strawberry yoghurt and orange juice. Luca decided to compliment me each time she sees me.

Dessert was microwave steamed pudding, now that I can finally make it again over here. My microwave ring pan went missing many months ago and I could not find anywhere to buy a new one over here, but while I was back in NZ my mum found one so I brought it back with me. It still did not work out quite right; despite adding extra flour I still had the problem I always seem to have over here of it not rising enough and not cooking through properly at the bottom (the top when it is tipped out). I am not sure what is to blame — it always used to work very reliably back in NZ. I can only assume the flour is different somehow, but I would have thought adding more to make the batter match in consistency would have fixed that. The golden syrup is different here too. Lighter.

Aga took lots of photos, so I guess they will be up on G+ shortly. Quote of the day was from Luca: “I bet desserts came very quickly after agriculture”. There was much hilarity all round. And some tomato paste. Luca and Emily (mostly Luca) decided they would buy muffins tins and a blender and start making muffins and smoothies. Apparently I am to come over and teach Luca to bake muffins as her parents neglected to show her this vital life skill. Should be fun.

We had some interesting conversations about gender roles, discrimination, hugs, muffins, haptic technology, robot cats, people, and accents.

My attempt at kidnapping was ultimately unsuccessful.

I should be trying to sleep.

Goodnight!

Oh, I should see if anyone wants to go up to St. Albans with me for a contra this Saturday.

[Edit 2013-05-14: Added links]

12 May 2013

Visiting home

Filed under: Travel — Tags: , , , , — qwandor @ 3:02 am

Back in London! (Well okay, I got back almost a week ago now, but I started writing this post on the flight from Sydney to Dubai.) That was an eventful visit back to Wellington: rain, sun, an indoor picnic, dancing, a couple of walks, various dinners, chats and catch-ups, playing in a playground in the middle of the night, star-gazing, painting a horse-jump to look like a sailboat, several attempts at geocaching with mixed success, and wandering around Sydney.

Before you get bored with the wall of text, here are some photos (or on Facebook if you prefer). Follow along if you like.

I spent just under 3 weeks in NZ, so a bit over 3 weeks away from London. My flight out, rather depressingly, left London on Sunday night to arrive in Wellington on Tuesday afternoon. I did not visit Auckland this time around, as I did not have quite so many people up there to see any more, so my only trip outside of Wellington was a day in and around Palmerston North. I went up with my mum to have lunch with my grandparents, one of my cousins and an aunt in Feilding, and saw the house my grandparents recently moved into in a retirement village there. They seem to be settling in well, though it is a bit smaller than their old house. I then spent some time with my friends Daniel and Sharon, whose wedding I went back for last year. Daniel has spent the last few months working as a grounds keeper at an equestrian centre just out of Palmerston North, and I ended up helping him with a few things he wanted to get finished before going home. In particular, he was repainting the stands for a horse jump to look like a sailing boat on the sea, so I painted part of that. I then headed to a family dinner with a different set of cousins and aunt, and my grandparents again. My cousin Lisa, who works as a chef, made us a very tasty dinner. I was then back down to Wellington first thing the next morning and back to work.

On Friday night some friends who blog together on common topics from time to time had organised a dinner to get together and chat, so as I was conveniently in town I was able to join them. I think there were about 14 of us who made it to the dinner, including a few hangers-on, and we had some good conversations over Chinese food at Cha. After dinner some of us went for hot chocolate and coffee somewhere else, and then I continued on to my friend Emma’s birthday party. She lives in a bit of a hippy flat in Mount Vic full of vegetarians and green activists, which suits her rather well. As well as a couple of other friends, there also happened to be a guy there with whom I had been friends in primary school, and probably not seen since, so we caught up a bit and he told me about his radio play. Wellington is full of connections like that!

On Saturday I had hoped to go for a walk, but the weather was not at all up for it, so instead a few friends came over to play card games and catch up, and then we made pizza together for dinner. I went back to my old church, The Street City Church, on Sunday morning, but did not see many people I knew there any more. Afterwards I had planned to have a picnic at Freyberg Beach to catch up with lots of people, but again it was raining so we had an indoor picnic at my parents’ house instead. Though not quite as good as the beach I think we did a decent job, with picnic rugs out on the carpet and even a stone turtle. It was good to catch up with everyone all the same, though as always at big gatherings it was hard to have many long conversations with people coming and going all the time.

Monday night I caught up with some friends from Memphis (the old compsci graduate lab at Victoria University) and Innaworks for pizza, Tuesday was dinner with the Hornblows (aunt/uncle/cousins on my mum’s side of the family), and Wednesday dinner with my old flatmate Richard and his wife Sarah. It was great to catch up with Richard about what he has been up to, and his plans to perhaps start a small local brewery with some friends following his recent success with a home brewed beer of his winning an NZ-wide competition.

Thursday was ANZAC day, so I took a day’s leave from work and got some friends together for a walk. 4 people came in the end: Cat, Gael, Jill and my brother Tim. We started at Aro Park, in Aro Valley, and walked up through Polhill Reserve to the Brooklyn wind turbine. From there we continued along the fenceline of the Karori Wildlife Sanctuary (aka. Zealandia) for a little, before continuing off along the ridgeline to Red Rocks, then back along the coastline past Owhiro Bay to Island Bay, from where we caught a bus home (except Cat, who decided to walk the whole way). I made a map of our route, or as near as I could get it. We stopped to look for a couple of geocaches along the way, though only found one of them. The weather started out rather rainy, for the first couple of hours, but cleared up beautifully in the afternoon. Cat managed the first hour or two of the walk (uphill, on gravel and mud) without shoes, but eventually gave up and put his shoes on.

NZ visit 2013: A curious sign along the way to Red Rocks

Thursday evening was dinner with some of the Walbran side of the family.

Friday night I went out for some swing dancing to see how the Wellington scene was doing, though sadly was not able to convince any friends to join me. It was pretty small, only about 10–20 people I think. After a couple of hours of swing they had a woman named Elizabeth Wise who was over from the US to sing and play some blues for us to dance to. By this point there were only about 10 people and not many dancing, but it was good music, and I had a few nice dances before I headed home.

My second Saturday in Wellington had much nicer weather than the previous one. We started the day with brunch at a local café to celebrate my dad’s birthday. My little brother Mark was down from Auckland for a few days as well, so it was cool to have all 5 of us together in the same place. After that, my friend Michael organised a walk at Otari-Wilton’s Bush, and I invited some more friends to join us. There were 8 of us in the end, which was an excellent number: me, Michael, Melissa, Isabel, Matthew Kiernan, Enoch, Josh Baker and Polly. This was a much shorter and easier walk than the previous one, and the weather was great all day. We took a few silly photos at the end, and after a little car trouble all headed our different ways.

I went to the Makertorium exhibition at Te Papa, a one-day showcase of all sorts of creations from people, clubs and companies around NZ. It was pretty cool. There were a lot of 3D printers and quadcopters, but all sorts of other things as well. I took a few photos, though they do not really do it justice.

After that I went to a friend’s house-cooling party in Mount Victoria, then Richard’s beer launch party. The prize for the homebrew competition he won was to have a brewery in Auckland make a batch of his beer, and so he organised a bit of a celebration at the Kelburn Village Pub, which had it on tap. Most of the people I knew had unfortunately gone by the time I arrived, but I did see a few on their ways home as I made my way up, and also got to see a couple of people I knew still there. I then got a last-minute invite to another friend’s flatwarming party up in the far reaches of Brooklyn, so walked all the way there to hang around for a bit, then all the way back home to Hataitai.

Sunday morning I visited the local Elim church where a number of my friends go, then caught up with a few friends in the afternoon, walking around the waterfront and then meeting some others in the Botanic Gardens. Emily, Beth and Teresa were all in Wellington for a few days, in a happy coincidence, so I was able to catch up with them to varying degrees.

The next Monday night I was invited to a party which was partly to celebrate my friend Josh Thompson getting back to Wellington, so it was good to catch up with him and my other friend Daniel. Tuesday night was dinner at the Greenhaus flat in Newtown with Peter and Elaine. Peter, being his usual self, had ended up double-booking himself so was not able to join us for dinner after all, but I made some dessert for us to share when he got back a bit later in the evening and before he had to go out again. And I had a great long chat with Elaine, catching up on and discussing all sorts of things. Peter, Elaine and I (plus a bunch of others) all used to flat together in 2008, my last year of university, and Peter and I were also friends from college.

Wednesday night I was able to join in a regular ribs night that some of the ex-Memphis crowd have, trying out different restaurants around the place. This time was Uncle Mike’s Kansas City BBQ in Petone, which was good. Thursday night I was originally planning to do some night geocaching with a few friends, but it was all a bit disorganised and then it ended up raining so we decided not to go after all. My friend Jill dragged me along to a ballroom dance class instead, which was interesting.

Friday afternoon I went to the Xero drinks for a bit to catch up with Will and Donald. Will was a colleague of mine at Google London, who recently moved back to Wellington with his wife and young kids after having lived in London for many years. He seems to be enjoying being back. Afterwards I was catching up with Talitha, as I had not yet seen her by that point. As we were looking for somewhere to eat we happened to run into my friend Tim Best, so he joined us for dinner at a nice Korean Barbecue place. That certainly does happen a lot more in Wellington than it does in London! Even in the less than three weeks I was back, there were at least 6 times I randomly bumped into people I knew around town.

On Saturday I had a wander around my old university, VUW, to see what had changed. They have built a new building where the quad used to be, with several levels of space with seats, desks, shops and so on connecting to the library. It all feels rather different to how it used to. I met up with Felix and Tim for lunch in town; Felix had been back in China for a while so I had not been able to see him earlier. I then met up with Emma for a bit.

On Saturday night I dragged a bunch of my friends along to a contra dance, which was good fun in the end despite a few problems. There has been a monthly contra in Wellington for about 10 years, with a band called Chilli Jam. I had only been a couple of times, years ago, but wanted to see what it was like compared to London, and to dance with as many of my friends as possible, so invited a bunch to go with me. The numbers had always been fairly small, but little did I know it had been declining recently, and they were planning to stop this year after the April dance (i.e. just before I got back). Fortunately they got an excellent turnout in April, and a friend of mine happened to be there and told them that they should keep on going at least a bit longer as I was organising a group to come to the next dance, so they decided to keep running them for the time being. Anyway, so I had about 10 friends or maybe even a couple more who came along, which was great. There were only about 30 people dancing in total I think, so I knew almost half the people there. However, we turned up on the night, and the band and caller were there, but the church hall where we were supposed to be dancing was locked and we could not get in. Apparently it was also full of junk for some reason. Fortunately it was a nice calm mild night, and we were able to get some power for the band and caller, so after sorting ourselves out we formed up in a longways set on the footpath outside and had our dance there, to the bemusement of all the passersby walking and driving through Kelburn village that night. The combination of uneven footpath, background noise, about 3/4 of the people never having done any contra before and people walking through made for a rather chaotic few dances, but they were good fun nonetheless, and quite a unique experience. We even managed to get a few passersby to join in which was cool. Perhaps this is something to do more often! I have danced Lindy Hop and blues outside a few times in London last summer, but not contra before. Oh, someone took some photos of us dancing. And one of my friends says we were mentioned in the local newspaper, though I have yet to see this.

Afterwards Polly had the excellent idea of organising a bunch of us to hang out for a while, so we headed down to Freyberg Beach in various cars to play on the climbing frame there for a bit and watch the stars, before heading to Enigma for some late night coffee and gelato. All in all, an excellent last night out in Wellington!

Sunday I went to church in the morning, then joined some people for lunch from the Chaffers market in Waitangi Park, then throwing a frisbee around for a bit. Great weather again. I then headed home to pack and get an early night, before getting up at 4:00 am on Monday to get to the airport and catch my flight out. By this point it had started to rain quite heavily, and apparently there was quite a bit of flooding in town on Monday, along with thunder, lightening and even an earthquake. It seems I got out just in time!

I spent the better part of Monday in Sydney, as I had a stopover there from 8:10 am until 4:05 pm. I had a walk around Centennial Park, as I had not been there before, then went for lunch at Google to catch up with Arya (a friend from university) and stretch (who used to be on my team at Google London). It was good to see them both, though I lost track of time a bit and ended up leaving at about 2:30 pm, only just in time to get to the airport and catch my flight. I had not meant to cut things quite so close. Anyway, the rest of the journey home was fairly uneventful, some minor delays due to mechanical problems and air traffic control meant I arrived in London about an hour late, but otherwise everything was fine and I managed to nap a bit on the flights. I arrived in London around 7:30 am, headed to work, and did a fairly decent job of staying awake all day. And now here I am!

Starting this Monday I am going to try blogging every day for a week, as something I am trying with some blogging friends. I may find this a struggle.

23 March 2013

NZ visit and miscellany

Filed under: Me, Travel — Tags: , , , — qwandor @ 8:54 am

Firstly, for those of you in NZ who do not pay attention to Facebook, I am going back for a visit in a few weeks. I fly out of London on 14th April and arrive in Wellington at 2:45 pm on Tuesday 16th April, and stay until Monday 6th May. I plan to spend most of my time in Wellington, other than a trip up to Palmerston North for a few days at some point. If you are keen to catch up, let me know and we can organise a time! I am keen to organise a few picnics (weather permitting), walks, dinner parties and so on, as well as dragging people out dancing. I should probably get on with that soon, I have just been too busy with other things.

In the meantime, I have a friend coming to stay next week, which I am looking forward to, and then am off to Marseille (and hopefully some of the surrounding countryside and towns) for 4 nights over Easter, flying out there on Easter Saturday and then back to London on Wednesday 3rd April.

At the start of this year I decided to make an effort to have people over for dinner more often, and that has been working out so far. I have had lots of different groups of people over for dinner over the last few months, and Rachel and Matthew have returned the favour several times to have me over for dinner at theirs. I think I have averaged about one night a week (or perhaps even a bit more) of either having people over to my place for dinner or visiting others. So definitely a success so far! Lots of tasty food, interesting conversations, some music, dancing in kitchens, and all sorts of fun.

On the topic of dancing and fun, I went up to IVFDF in Sheffield a few weeks ago, which was good fun. Learnt some new dances (there were an enormous range of workshops), got to see what folk dancers make of blues, heard lots of great music, and did not sleep or eat all that much. Definitely well worth it.

18 February 2013

String colouring

Filed under: Maths — Tags: , — qwandor @ 8:08 am

One of my colleagues has an interesting combinatorial problem, perhaps the mathematically-minded among you might be interested to think trying to find a solution:

“I’m trying to work out the minimum size of a colouring of strings on a finite ordered alphabet, as follows.

Let Q be the set of integers from 1 to q, {1,…,q}

We consider all strings of length n on Q represented as path graphs with labelled edges:

Let G be the set of all qn path graphs consisting of n+1 nodes and n edges where there is an edge between node ni and ni+1 for each i = {1,…,n} and each edge is labelled with a integer from Q.

For any two nodes e and g on a graph in G, let max(e,g) be the highest label on the path between e and g.

Each node x in each graph in G is assigned a colour colour(x) from a set of colours C such that the following constraint holds:

For any pair of colours (a,b) from C, there is an integer f(a,b) in Q, such that whenever a and b appear on a graph in G, say colour(x) = a and colour(y) = b, then max(x,y) = f(a,b).

Question:

  • If q is constant, what is the minimum size of C?
  • What is the minimum number of colours I need to colour there graphs so that the maximum label between a pair of colours is always the same?

So far, I’ve manage to bound the minimum size of C between O(nq) and Ω(n logn). ie. O(nq) colours are sufficient but it can’t be done with fewer than Ω(n logn) colours.

Can you

  1. Show that there is a colouring of size O(n logn) or
  2. Come up with a higher lower bound? For example, show that a colouring has to be at least say 0.5n0.5q to respect this constraint

This problem has ratifications on unsolved problems in complexity theory related to the complexity of parity games and modal mu.”

Any thoughts? It has been far too long since I have done any real maths.

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