Introducing: System.Numeric.BigInteger [Inbar Gazit]

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Levi — Wed, 17 Jan 2007 10:55:37 GMT

Excellent work on the BigInteger type! I've been going over the assembly with Reflector, and it looks like it will be very useful.

One concern, though - the type uses managed arrays as a backing store. It is likely that many people will implement cryptographic operations using BigInteger, and the potential for sensitive information (keys, etc.) to remain in memory is high. Is there any plan to mitigate this risk, or am I missing some implementation detail and overthinking here?

Thanks!

New BCL type: BigInteger

Ernst Kuschke — Wed, 17 Jan 2007 13:14:00 GMT

There's been a need for this for some time, and the guys have finally included this new BCL type in the

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Chyld Medford — Wed, 17 Jan 2007 21:07:13 GMT

awesome work! i can't wait to use it.

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Jon Skeet — Thu, 18 Jan 2007 00:34:17 GMT

The most important (good) part of the naming decision, IMO? It's the one all Java programmers will look up first when they want to find the type.

So, can we expect BigDecimal next? :)

Jon

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Chyld Medford — Thu, 18 Jan 2007 02:13:19 GMT

TrackBack from http://chyld.net/CS/blogs/cmedford/archive/2007/01/17/that-s-so-big-of-you.aspx

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Chyld Medford — Thu, 18 Jan 2007 04:05:49 GMT

I ran the code supplied above and gave it 4000 to find the factorial and it worked, but when I gave it 5000 I got a StackOverflowException. Why is this? I have over 1GB memory - it seems like it should of worked. Any thoughts?

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Inbar Gazit — Thu, 18 Jan 2007 07:29:51 GMT

Sorry, the way I implemented Factorial is using recursion which means that we are going to use the stack before we run out of memory as each time you make another call into Factorial the stack grows and the number of calls is the factorial you are trying to implement. You can write this method in an iterative way using a simple for loop and you would avoid this issue.

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

grauenwolf — Thu, 18 Jan 2007 09:05:18 GMT

That's cool and all, but are you going to create an INumeric interface so I can use generics with it?

You know, something that supports this syntax

Function Average(Of T AS INumeric)(a as T, b as T)

Return A.Add(b).Divide(2)

End Function

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Chyld Medford — Fri, 19 Jan 2007 06:49:08 GMT

I changed the recursion to a loop and then computed the factorial for 50,000...the article with the results are here: http://chyld.net/CS/blogs/cmedford/archive/2007/01/17/that-s-so-big-of-you.aspx

Introducing: System.Numeric.BigInteger

DotNetKicks.com — Fri, 19 Jan 2007 10:01:46 GMT

You've been kicked (a good thing) - Trackback from DotNetKicks.com

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Oleg Ufaev — Fri, 19 Jan 2007 10:44:56 GMT

>Bitwise operations are not supported, but we will have an MSDN article coming soon with how to write your own library extension of BigInteger.

"Great Idea"

May be include extension code example from article to BigInteger standart implementation? I can't understand your policy: write article about how inmplement bitwise operations and not implement it in BigInteger.

Bitwise operation are used often!

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Vadimmer — Fri, 19 Jan 2007 21:24:37 GMT

IMHO BigDecimal and bitwise operations are extremely needed

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

George Tsiokos — Fri, 19 Jan 2007 22:24:53 GMT

We definitely need the ability to work with numeric types in generic methods.

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Aaron — Sat, 20 Jan 2007 12:20:53 GMT

Wow, I am so used to working with Java and C# at the same time I always just assumed that .NET had a BigInteger type already ;)

Well, I guess better late than never. I do wonder what the BCL people were doing when they designed certain parts of the framework initially. This reminds me of the total absence of a LinkedList type of collection class before 2.0. How could they forget something like that? I wanna call "slackers", but other parts of the BCL are so well though out. Its perplexing.

On a different note, why does every MS project have a "code name" that has nothing to do with the project or what the project will really eventually be called? Seems goofy ;)

Welcome to the Future

Runar Jordahl — Tue, 23 Jan 2007 14:34:42 GMT

Smalltalk had “LargeInteger” since the 1970s.

In Smalltalk you do not even need to type your variable to LargeInteger: Any computation with an integer that flows over, will automatically convert to LargeInteger.

Welcome to the Future?

Tim — Wed, 24 Jan 2007 02:06:02 GMT

wow, bitwise operations are a part of all Smalltalk integer types. Simply because they inherit from the class Integer.

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Ri Geon-Un — Mon, 29 Jan 2007 18:41:32 GMT

Congratulations on the implementation of the BigInteger class.

Now we need a BitStreamReader and a BitStreamWriter class. :)

The .NET Framework is immense, but I feel it's quite lacking.

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Lem — Tue, 30 Jan 2007 23:50:49 GMT

Nice class, gonna try to take fun!

And don't forget that 0! = 1! = 1

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Fduch — Sun, 04 Feb 2007 17:01:03 GMT

System.Core.dll

Hmmm....

It's cool name but is it good?

System.Numeric.BigInteger

Small place on earth — Wed, 14 Feb 2007 18:10:29 GMT

În versiunea Orcas de .NET s-a introdus un nou namespace: System.Numeric. În acest namespace se regăseşte

.Net Framework 3.5 - System.Core.dll

Mike Chaliy's Blog — Thu, 15 Feb 2007 17:41:56 GMT

Незабаром в нас буде нова версія .Net Framework 3.5, яка схоже, як і 3.0, буде спиратися на базовий .Net

re: Introducing: System.Numeric.BigInteger [Inbar Gazit]

Sharp Fool — Fri, 16 Feb 2007 02:13:47 GMT

I would like to propose the inclusion of

a function

BigInteger BinaryShift(BigInteger b, int n) {

return b * BigInteger.Pow(2, n); }

This function is a convenience only, but an

important one when porting code from other

languages. For example it could replace the

ubiquitous Java functions

BigInteger shiftLeft(int n) [this << n]

BigInteger shiftRight(int n) [this >> n]

And, of course, it can be implemented much more

efficiently compared to the function above.

My second suggestion is a much more important

one. I think it is almost a must to have the

functions

Product(T[] a)

Sum(T[] a)

and for slices of T[]

Product(T[] a, int start, int end)

Sum(T[] a, int start, int end)

for T in {int, long, BigInteger}.

Well, you might answer a simple foreach loop

will solve this task. And I think a great many

people will indeed implement it in this way.

However, this is the most inefficient way to

compute a sum or a product. For *big* numbers

sequential adding or multiplying tends to be

'unbalanced', a small term or factor is paired

with an increasingly large one. Bad.

Much better is the strategy of binary splitting. Just for illustration of the idea:

BigInteger recProduct(BigInteger[] s, int len) {

if (len == 0) return BigInteger.One;

if (len == 1) return s[index++];

int len2 = len >> 1;

return recProduct(s, len - len2)

* recProduct(s, len2);

}

And the only 'right' place to implement this

is BigInteger, of course.

Furthermore, something like Product(T[] a) and

Sum(T[] a) assists the trend to functional

programming in C# 3.

So go ahead and show us some improvement over the BigInteger library of Java, written 15 years ago.

Cheers SharpFool

BigInteger type in Orcas

MikeWo's Musings — Sun, 01 Apr 2007 20:30:20 GMT

So, you know I was thinking, Int64 is just too limiting for my integers. I mean, I might generate a product...

Visual Studio Code Name "Orcas" Beta 1 Has Been Released! [Inbar Gazit]

BCL Team Blog — Sat, 21 Apr 2007 00:26:09 GMT

I'm pleased to let you all know that Microsoft released the first beta version of the next version of

New .NET 3.5 core stuff

Patrick Smacchia [MVP C#] — Wed, 08 Aug 2007 22:22:09 GMT

While installing VisualStudio 2008 Beta2 I was surprised that the NET framework 2.0 installation got

PDC Day 3: What's Coming in CLR 4.0 (Part 1)

All Your Base Are Belong To Us — Thu, 30 Oct 2008 23:07:04 GMT

Joshua Goodman's session on CLR futures was packed - the crowd of developers wanted to learn what's