User talk:Slaunger/Archives/2010/1

New Year's greetings

Dear Kim,

Greetings from my stormy Portugal to you and your family! Even in Xmas time I can't be away from my beloved sea. -- Alvesgaspar (talk) 14:57, 2 January 2010 (UTC)

Stormy sea in Porto Covo, Portugal

Thank you, Joaquim for your greetings and your wonderful storm! --Slaunger (talk) 18:39, 2 January 2010 (UTC)

Let's say problem #10

Hi Kim, Thank you for correcting the dates in my archive :) Let's please talk about problem #10. I of course solved it, but it took 40 minutes or so to run. I am using Basic BTW. Here's how I tried to speed it

up:

1. In my main for loop I used step 2 (no need to check even numbers)
   • What you could do to speed this up is to remove all factors of 2, 3, and 5, such that you repeat candidates numbers with a period of 2*3*5=30, using whats left, which is 1, 7, 11, 13, 17, 19, 23, 29. This means you need to test 7 instead of 15 numbers for each interval covering 30 integers, which should give you a x2 speed up
2. I calculated square root of the numbers, and used integer of that value for my second for loop to run to
   • You mean that you maintain a list/array of already found primes up to sqrt(pmax) and use them for division? If yes, that is correct.
3. I exited my second for loop (the one for division) as soon as a number was divided with no reminder.
   • Yes.

So my question is: Am I missing something else to make it run faster, or a slow performance is because of Basic and my old computer?

You use Basic in a version where I guess each line is interpreted as you go along (I have not toyed with basic in 18 years or so, so I do not recall the possibilities in the language). My guess is that the actual intrepretation of each line is taking considerably longer than the actual computation, be it a modulus operation, the incrementation of a candidate number, etc. I use Python, which has the same disadvantage (but powerful in many other ways). The trick you make there to speed things up is to make it do as much as possible in one line, such that the interpretation of the line is neglible as compared to the actual computation. So you try to vectorize/linearize it as much as possible. In Python I use the efficient range and set operations in Python on chunks of numbers to accomplish that. I do not know the possibilities in BASIC, but surely it should be possible to linearize the bottlenecks somehow.

Another trick is to avoid division and multiplications of integers as addition/subtraction is cheaper. You can to that by "sieving" the numbers using the sieve of Erasthostenes.

Using these tricks, I can compute the result in 0.34 seconds on my 2 year old midrange laptop.

It is worthwhile to take the time to implement a good and efficient prime sieve, as prime number generation is used over and over again in the problems. Later you may also want to implement a Rabi-Miller is_prime test, as there are quite a few problems where it is handy to be able to efficiently test if a given (sometimes very large, like in problem 60) number is prime, without knowing all primes up to sqrt(n) and do all the trial divisions.

Thank you.--Mbz1 (talk) 20:18, 5 January 2010 (UTC)

Hope this helps and have fun. --Slaunger (talk) 21:23, 5 January 2010 (UTC)

Come on now, you two. Math is a precise science, and you're telling me to to implement a Rabi-Miller is_prime test with all its strong liars? Don't you see I have more than enough strong liars to deal with already? :) Thank you. I will think about the suggestions. --Mbz1 (talk) 02:50, 6 January 2010 (UTC)

Thanks generally

For the time taken to comment on a number of FPs. I have made a brief response on mine - I cannot honestly say I disagree with some of your points made. Equally I find myself in agreement with some of your other FP comments too and will re-read them in more detail. Regards --Herby ^{talk thyme} 09:29, 22 January 2010 (UTC)

It is only rarely seen that a user is being thanked for being the sole oppose of an image nominated by the creator! But I am glad that you appreciate my comments there and elsewhere! I have taken my saturation claims back in the review of your image after reading your response. I have also noticed the diligence you exert in your reviews. it is a pleasure to see the photographer side of you after having seen you in another role here for several years (which you also did very well). It seems like you are enjoying your new Alpha 350. I got myself an Alpha 300 last spring and I am very happy about that too, but quite frankly not yet symbiotic with it. --Slaunger (talk) 10:13, 22 January 2010 (UTC)

At the risk of boring you

My life has changed somewhat over the last 12 months and I decided to take photography more seriously than I had. I am happy to contribute images to Commons however I am also using Commons to learn. I tried a camera club but found such things did not work for me and then realised I was already part of such a club here in some senses. As such feedback is appreciated.

As to the camera I confess it was bought with a degree of ignorance at the time (I do know more now) but I am fairly happy with it and do not regret the investment. It is less good in low light than I would like (I saw some images a while back taken at 8000iso on a Nikon that were infinitely better than mine at 400iso) and I may get tempted with a full frame camera at some stage. The lens, while ok, irritates me with its failings - ca mainly but, as you noticed, some issues with wide angle work too. However at the time I was not prepared to spend more. Given the fact that much of what I do involves walking some distance I guess any lens will need to be a compromise as I would prefer to use one mostly. I'm not sure I am symbiotic yet but the shutter has fired rather a lot of times since I got it.

I certainly share your enthusiasm for early and late light.

Thanks again for your comments both here (kind of you) and in FP generally. Regards --Herby ^{talk thyme} 10:41, 22 January 2010 (UTC)

You are certainly not boring me. I find it delightful to correspond about spin-off topics from core Commons work on my talk page. Yeah, I also dream of better equipment, but I still think I have a lot to learn with what I have. I rarely have dedicated (daylight) time to just photograph, but I enjoy it when targets of oppurtunities pop up. --Slaunger (talk) 22:04, 23 January 2010 (UTC)

The old chapel

Strangely I awoke in the night with a similar idea! I've uploaded a crop here, your views more than welcome. I am not totally happy with the perspective correction but that was commented on at QI (although I had a little help there). It has been through both manual and automatic correction (Shift_N). The roof is fine as are most of the verticals but maybe not all (I think in part it is an illusion due to the hill it is on). Given it is significantly older than both of us combined some movement might well have occurred I guess. Depending on the day I'll put it in FP later. Thanks & regards --Herby ^{talk thyme} 10:28, 24 January 2010 (UTC)

Retouch

Hi Slaunger,

With regards to the retouched template in the uploaded fruit stand picture, technically speaking the image is not retouched, at least not in the traditional photographic way.

A retouched picture is that which alters elements of the image, replacing or hiding elements. Removing moles from faces, changing colors, etc.

I am basically a purist in photography, meaning that I do very little alterations to the images.

The alterations that I did are comparable to traditional darkroom practices using the yellow/cyan/magenta filters on traditional enlargements, which do not constitute manipulation.

I am a photo.net user, and they have a definition of manipulated vs unmanipulated, and this image falls, according to that criteria, under unmanipulated image. Please see http://photo.net/photodb/manipulation

It is an interesting point you raise here, but I am a stubborn old school photographer.

In darkroom photography we have yellow, cyan and magenta filters to correct or adjust color and/or finetune the final print for display lighting conditions, etc., because color is really a funny thing. Nowadays, color depends more on the monitor of the viewer than on the information itself, and we also have to worry about the output, different printers will provide different results.

In black and white we used magenta for contrast in multigrade papers or used different grade papers to match the density of a given negative and the desired result.

I am not just stubborn by holding on to analog photography practices, but as in painting, painting done in watercolors, oil or acrylic adhere to base painting principles, and photography is no different. Analog and digital photography share the same core attributes. This is a medular point that analog and digital photographers fail to see. Good photography is more the result of vision, and the capacity to capture the raw information either on film or sensor, and then proceeding to render the image seen by the brain, not the camera. Cameras, analog or digital are just a medium. Vision is what it is all about.

A good poem can be written by hand, in typewriter, in computer... the medium does not make it better or worse... photography is the same...

And with the risk of being redundant, this quote applies:

The notes I handle no better than many pianists. But the pauses between the notes--ah, that is where the art resides! Arthur Schnabel, in Chicago Daily News, June 11 1958 Austrian composer & pianist (1882 - 1951)

--Tomascastelazo (talk) 23:39, 26 January 2010 (UTC)

Hi Tomás,

Thank you for telling me about your thoughts about what retouched is what is not. I actually agree with you that it is not a retouched photo in the traditional sense, and I did suspect that my mentioning of the template would trigger a reaction for you ;-). In the description of the template it says that when it is placed on an image page it "...means that it has been digitally altered from its original version. Modifications: ...". Being stubborn as well (and semi-old) I would say that the "dark room" adjustments you have made is a digital alteration from the original version, although of a purist nature emulating dark room techniques. However, I also agree with you that the name of the template is misleading as its scope is stretched beyond what is traditionally meant by retouching. And in practise there is also great diversity in how the template is applied on Commons. Quite a big fraction of users would not use it if they have made adjustments to the curves, or if they have applied moderate sharpening. And others are happily unaware of its existance. So, if you personally dislike using the template, don't use it! Just add what you have done to the image page in the description. I think only a minority of the reviewers and especially the users of Commons photographs are familiar with dark room techniques for color photography. A larger fraction would be familiar with B&W dark room techniques as these have been more available for non-professionals, but most are probably only familiar with digital photography and PS. Personally, I attended a course in photography in the mid eighties as a teenager and learned how to develop and to some extend manipulate exposures in B&W photography. I have also tried to manually retouch a B&W photo to remove a spots/defects in the image, but that is where it stop for me, and probably before that for many others.

Since you make some interesting points about the "old school" techniques you emulate in PS it would be worthwhile to flesh that out in quite some detail on the file page such that others could become knowledgeable about it and perhaps even learn from it, or could reproduce it. After all Commons media main purpose is to be educational and informative. So, getting back to my own stubbornness. Would you be so kind to add to the file page description what "dark room" manipulations you have done to achieve the result you have there? It adds value and most users will not understand it if you just refer to it as typical dark room techniques for color photography.

--Slaunger (talk) 07:31, 27 January 2010 (UTC)

{{VN/title}} & {{Synonyms/title}}

Hello my friend, as we are talking about {{VN}} & {{Synonyms}}, could you add a |da= section in {{VN/title}} & {{Synonyms/title}}?
That would allow you to spot them more easely.
Cheers Liné1 (talk) 06:33, 28 January 2010 (UTC)

Hi Liné1, my friend.

Thank you for your message. A seemingly simple task to add the da version is turning out not to be so simple for me, as I am a little bit in doubt about the best and most precide Danish terms for these words. I have conferred with a local expert I know, as I would like to do it right. --Slaunger (talk) 10:02, 28 January 2010 (UTC)

hihi, I tried to asked hu.wikipedia for the same, and the thread is still running. Is this a biology troll of some sort ?

Cheers Liné1 (talk) 10:49, 28 January 2010 (UTC)

 Resolved and implemented Quite fast, eh? --Slaunger (talk) 21:58, 28 January 2010 (UTC)

Thanks a lot. Now, do you know someone fluent in another langage that is not in those title. You see, the quicker you are, the more job there is ;-) Cheers Liné1 (talk) 07:32, 29 January 2010 (UTC)

Maybe, I've contacted a Swede and asked that user to find another user speaking another missing language when he is done, hoping for a chain reaction (albeit the chain is fragile as it does not branch out). --Slaunger (talk) 08:03, 29 January 2010 (UTC)

New VI set

Hello Slaunger, I'd like to know your opinion on this new VI set, just to better understand what a VI set actually should be. Is this one would be OK to you? Thanks in advance, --Myrabella (talk) 07:48, 28 January 2010 (UTC)

Hi Myrabella,

Thanks for your proactive notice regarding the new set on my talk page. I will have a look at it. A bit busy right now, but I will get to it soon. And thanks in general to help keep the VI project floating with your enthusiasm. --Slaunger (talk) 10:05, 28 January 2010 (UTC)

 Done --Slaunger (talk) 21:04, 30 January 2010 (UTC)

A big and enthusiastic thank you for this review and the other ones! --Myrabella (talk) 22:08, 31 January 2010 (UTC)

• I've changed the scope based on your recommendation. 99of9 (talk) 21:56, 30 January 2010 (UTC)
  • No worries, mate! I also noticed, as I always put images I edit on my watchlist, but thanks for notifying me proactivlely. --Slaunger (talk) 22:07, 30 January 2010 (UTC)

May I use use Your photo

Dear Sir!

My name is Igor, and I found your photos at wikimedia. You are great! Realy!

Now I am writing the screensaver, were there real and unreal landscapes became alive: the dancing fountains appear there. It is just a nice ralaxing fantasy.

May I use use Your photo "Nuna_island_Upernavik_district_2007-08-09_3" in my screen saver? It is almost ready, I hope to launch it in a couple of weeks. I can't find any mention in usung of your images in screen savers. I would like to add aYou as copyright owner to the main scee saver window and a link tom Your website.

Please let me know if I can use Your image in my work. I think that it can help to promote Your sime and Your great images too.

PS. screen saver release is not ready yet, so I can't send You a working copy. I will post You a link as sonn as it will be ready.

Thank You and best regards, Igor. agilescreensavers@gmail.com