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I just discovered this myself.
I am not sure the results are good enough, seems like they took the easy way out
(without much HSL conversion); DarkDark as far as I can see is always Black ?
Luc Pattyn [Forum Guidelines] [My Articles]
this weeks tips:
- make Visual display line numbers: Tools/Options/TextEditor/...
- show exceptions with ToString() to see all information
- before you ask a question here, search CodeProject, then Google
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Luc Pattyn wrote: I am not sure the results are good enough
You are right about the quality. But you can be lazy (ControlPaint) or good (do it your own way).
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Researchers in England may have finally settled the centuries-old debate over who gets credit for the creation of calculus.
For years, English scientist Isaac Newton and German philosopher Gottfried Leibniz both claimed credit for inventing the mathematical system sometime around the end of the seventeenth century.
Now, a team from the universities of Manchester and Exeter says it knows where the true credit lies — and it's with someone else completely.
Article[^].
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Hi,
this may interest me, unfortunately Internet Explorer 6.0 crashes on the link. 
Firefox survives it tho.
Luc Pattyn [Forum Guidelines] [My Articles]
this weeks tips:
- make Visual display line numbers: Tools/Options/TextEditor/...
- show exceptions with ToString() to see all information
- before you ask a question here, search CodeProject, then Google
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Luc Pattyn wrote: this may interest me, unfortunately Internet Explorer 6.0 crashes on the link.
Hmmm, it was fine for me and I was using IE...
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All they say in that article is that they discovered an infinite series without saying what it was. I don't really see what infinite series has to do with calculus. I think I'd need a more more information than that before I could judge wether they had really discovered calculus. The positive integers from 1 to infinity are an infinite series and I wouldn't rate them highly for discovering that.
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A Noteworthy Programmer wrote: I don't really see what infinite series has to do with calculus.
Just about everything, actually...
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Infinite series are used for way more that just calculus. Calculus is involved with the study of what happens when you let the step sizes used in area calculations and gradient calculations and such like become infinitlely small.
An infinite series is genereally any equation who's terms go forever, which could be like the series 1/2+1/4+1/8+... etc...
Anyway my main point is that they didn't really say what those Indian mathematicians had discovered which is what I was really interested in knowing on reading that article. Maybe this news item is on some other web site with more information?
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Actually searching the web lead me to this article on wikipedia that explains about some of the stuff they did:
http://en.wikipedia.org/wiki/Kerala_school_of_astronomy_and_mathematics
It seems they developed the equations for the sine & cosine function and others.
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A Noteworthy Programmer wrote: nfinite series are used for way more that just calculus. Calculus is involved with the study of what happens when you let the step sizes used in area calculations and gradient calculations and such like become infinitlely small.An infinite series is genereally any equation who's terms go forever, which could be like the series 1/2+1/4+1/8+... etc...
What are you telling me this for? I'm a theoretical physicist! 
A Noteworthy Programmer wrote: Anyway my main point is that they didn't really say what those Indian mathematicians had discovered which is what I was really interested in knowing on reading that article. Maybe this news item is on some other web site with more information?
I posted it here for general interest. I'm sure if you search the math periodicals from a university website you can probably locate an article of some kind by searching for the authors...
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73Zeppelin wrote: What are you telling me this for? I'm a theoretical physicist!
Thats funny, I used to work in Physics! I worked at this place called JET near Oxford in England that researched nuclear fusion. I used to program in FORTRAN, a language that you hardly ever here about these days.
Nowadays though, I program computer games for a living and genereally in C++.
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The integral is an infinite sum of infinitesimally small numbers.
Edit: And the general solution to the value of a converging infinite series is done via integration.
--
You have to explain to them [VB coders] what you mean by "typed". their first response is likely to be something like, "Of course my code is typed. Do you think i magically project it onto the screen with the power of my mind?" --- John Simmons / outlaw programmer
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I thought that was known for a long time ???
Me think "inventions" such as these were invented pretty much everywhere at about the same time; maybe was are to believe it was invented by an occidental (European) because they were the ones to "formalize" it and that the means of knowledge distribution was only better there than, for example in India or China or maybe in South America.
Also, the colonization of India and the rest of the world by Europeans might have try to erased some part of history that made them looked "bad" or "retarded" in some fashion compared to the cultures they colonized.
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I thought it was, "the first caveman who threw a spear".
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My mathematical skills are weak but I need to calculate a week number based on a date. The week number will be either 1, 2, 3 or 4.
I have a base date for a week 1 within the calendar year, which is always a monday, for example 15th Jan 2007.
Therefore, if I enter a date of 22nd Jan 2007 I need a return value of 2 representing week 2, likewise for 23rd through to 28th Jan 2007. 29th Jan 2007 through to 4th feb 2007 would return week 3 and so on.
Just to clarify my calendar is divided in 4 weekly cycles, and I need the week within the 4 weekly cycle that a date falls in.
I would be grateful for any assistance on creating a formula to provide this information.
Steve Jowett
-------------------------
Sometimes a man who deserves to be looked down upon because he is a fool, is only despised only because he is an 'I.T. Consultant'
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Exactly how you do this depends on the language / support for calculating differences between dates. The formula you want is:
week number = ( ( (day(date) - day(base)) / 7 ) % 4 ) + 1
where day(date) - day(base) is the number of days difference between 'date' and 'base', and is assumed to be an integer.
e.g.: day(tomorrow) - day(today) = 1
% is the remainder operator in C/C++, so 4%4 = 0, 5%4 = 1, 6%4 = 2, 7%4 = 3 and so on
Peter
"Until the invention of the computer, the machine gun was the device that enabled humans to make the most mistakes in the smallest amount of time."
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Thanks Peter, you're the best.
Steve Jowett
-------------------------
Sometimes a man who deserves to be looked down upon because he is a fool, is only despised only because he is an 'I.T. Consultant'
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I have a 64 bit integer (C# long). Apparently the file format I'm writing (Internet Explorer cookies) wants the "high part" and the "low part." I'm pretty sure that the low part is just thingy >> 32. What about the high part...?
My integer is signed.
Thanks!
-Domenic Denicola- [CPUA 0x1337]
“I was born human. But this was an accident of fate—a condition merely of time and place. I believe it's something we have the power to change…”
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Hi,
that would be wrong.
the low part is the result of anding with a mask containing the bits you want,
for 64-bit that would be 0x00000000FFFFFFFFL (L suffix for ulong).
[Addition: the alternative is to cast to (uint)]
the high part is what you get if you right-shift an unsigned long
over 32 positions;
or simply cast to uint
The fact the Intel and the like store numbers the other way around has nothing
to do with it, since you are performing mathematical operations here, not
memory access operations.
I trust you could have figured this out yourself with a couple of small experiments ?
-- modified at 3:40 Friday 3rd August, 2007
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Interestingly, my experiments don't exactly follow your predictions...
long ticks = (new DateTime(2003, 3, 18, 21, 22, 10, DateTimeKind.Local) - new DateTime(1601, 1, 1, 0, 0, 0, DateTimeKind.Utc)).Ticks;
ticks >> 32: 29552020
(ulong)ticks >> 32: 29552020
ticks & 0x00000000FFFFFFFFL: 1869262080
(uint)((ulong)ticks): 1869262080
(uint)ticks: 1869262080
In particular casting to uint seems to give the same result as the bitmask, and not as the shifting, and signed versus unsigned doesn't seem to matter much (probably because all my numbers are positive and not too large?)
Also, strangely enough, the original source for which I'm working on this (see here) seems to want to want to multiply the high part by 2? Any reason why it would do this?
(Backstory: I have a Cookie object in .NET, and I want to write it to the Internet Explorer cookies file. Which has this wierd date format based on the high- and low- parts of a 64-bit ticks integer. But, as you can see above, apparently they multiply the high part by 2 before storing it.)
-Domenic Denicola- [CPUA 0x1337]
“I was born human. But this was an accident of fate—a condition merely of time and place. I believe it's something we have the power to change…”
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Sorry, I added the "or simply cast to uint" at the wrong position.
Obviously it holds the lower half, it couldnt possibly hold the upper half.
signed >> replicates sign bit, so resulting value does not equal high part.
Anyway, you now grasped the value of a little experiment.
In future, when interested in bit-related stuff, I suggest:
- you start with a known value, a very good one is 0x0123456789ABCDEFL and the like;
- you print everything in hex format e.g.with ToString("X16") or something similar.
Then it is quite apparant what is going on. Decimal printout completely hides
the bits, hex shows them much better.
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Luc Pattyn wrote: the high part is what you get if:
- you right-shift an unsigned long over 32 positions;
- or simply cast to uint
The above statements are incompatible. IMHO performing a uint cast provides the low part.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
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Of course, that was a lapsus; it got spotted and rectified by the previous two
messages. I now have modified the original post.
Greetings.
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Luc Pattyn wrote: it got spotted and rectified by the previous two
messages
I quikly read that messages and missed the point
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
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They're all wrong. It's known that Archimedes reached some conclusions which couldn't be reached without at least the most basic of what can be called "calculus," though no body's found a record of his exact steps.