Displaying 20 results from an estimated 10000 matches similar to: "hashing using named lists"
2005 Jan 06
5
How to avoid rounding of matrix elements?
Hi all R-users,
If I have a matrix with numeric elements as follows, the values are
rounded when I try to refer to a specifici element using [], the value
is rounded.
The same thing happens if the matrix is read from a file, the values are
stored to the correct precision but then when I try to refer to a
specific element (such as using [], it is rounded.
How do I avoid this rounding?
2020 Jun 17
2
subset data.frame at C level
Hi,
Hope you are well.
I was wondering if there is a function at C level that is equivalent to
mtcars$carb or .subset2(mtcars, "carb").
If I have the index of the column then the answer would be VECTOR_ELT(df,
asInteger(idx)) but I was wondering if there is a way to do it directly
from the name of the column without having to loop over columns names to
find the index?
Thank you
Best
2016 May 24
5
IPv6, ULAs and FreeBSD
Hello,
I already consulted related lists @freebsd.org [1,2] but I have remained
unsuccessful to solve the following issue: VPN works for an internal
IPv4 subnet, but I doesn't for an internal IPv6 subnet with ULAs. To be
honest, I don't have any experience setting up a local IPv6; so I guess
that I'm doing something wrong here.
For those that know FreeBSD: The main aim is to connect
2009 Sep 09
2
vector of Vectors
I just learned that vectors can't contain vectors, which frankly simply confuses me (can you imagine arrays or lists in any other language not being able to contain arrays or lists?). At any rate, I need to create a data structure (size to be determined at runtime) which I will instantiate and then fill with vectors using a for loop. Clearly I'm new to the R game. Data Frame doesnt seem to
2010 Aug 04
1
Optimising the Rsync algorithm for speed by reverting to MD4 hashing
Hi,
From v3.0.0 onwards the hash function implemented by Rsync was changed from MD4 to MD5 (http://rsync.samba.org/ftp/rsync/src/rsync-3.0.0-NEWS). My understanding is that MD5 is a more secure, slower version of MD4 but I am not convinced that the added security of MD5 would alone have merited the change from MD4 (particularly since MD4 is ~30% faster than MD5). I wonder if I am missing other
2012 Feb 13
0
[LLVMdev] We need better hashing
On 13 February 2012 00:59, Talin <viridia at gmail.com> wrote:
> Here's my latest version of Hashing.h, which I propose to add to llvm/ADT.
> Comments welcome and encouraged.
> /// Adapted from MurmurHash2 by Austin Appleby
Just out of curiosity, why not MurmurHash3 ? This page seems to
suggest that #2 has some flaw, and #3 is better all round:
2006 Apr 25
4
Help needed
Hi,
I am trying to change a SAS macro to R.
here is my code. I get an error at the last line.
attach(fram)
dset1<-cbind(AGE,BMI,DEATH)
> BMIGRP<-cut(BMI,breaks=3,right=TRUE)
> AGEGRP<-floor(AGE/10)-2
> dset<-cbind(AGEGRP,BMIGRP,DEATH)
> maxage<-max(dset[,1])
> minage<-min(dset[,1])
> #maxcls<-dset[,2]
> #mincls<-dset[,2]
>
2004 Aug 12
2
Hashing table based on FWMARK
We currently use iptables, matching packets based on IP address and marking
them with an ID. Multiple IP addresses can be marked with the same ID. We
then filter based on the ID. We have close to 2000 filters now and I''m
looking into hashing tables. Is there any way to create a hashing filter
based on the fwmark?
Paul C. Diem
PCDiem@FoxValley.net
2012 Jul 27
4
why order doesn't work?
hi all,
I want to get a cumsum according to the order of some variable.
However, it doesnt' work.
For example,
**********************
test<-data.frame(cbind(x=c(3,5,2,6,7),y=c(8,1,4,9,0)))
test[order(test$x),]$sumy<-cumsum(test[order(test$x),]$y)
**********************
R complians Warning message:
In `[<-.data.frame`(`*tmp*`, order(test$x), , value = list(x = c(2, :
provided 3
2012 Feb 14
0
[LLVMdev] We need better hashing
On Feb 13, 2012, at 1:27 AM, Jay Foad wrote:
> On 13 February 2012 09:22, Jay Foad <jay.foad at gmail.com> wrote:
>> Would it be possible to use CityHash instead for strings?
>>
>> http://code.google.com/p/cityhash/
>
> Incidentally there was talk of using CityHash for LLVM's StringMap
> last year, but I don't think it ever came to anything:
>
2012 Feb 13
2
[LLVMdev] We need better hashing
On 13 February 2012 09:22, Jay Foad <jay.foad at gmail.com> wrote:
> Would it be possible to use CityHash instead for strings?
>
> http://code.google.com/p/cityhash/
Incidentally there was talk of using CityHash for LLVM's StringMap
last year, but I don't think it ever came to anything:
http://lists.cs.uiuc.edu/pipermail/cfe-dev/2011-April/014656.html
Jay.
2016 Jul 26
2
New password hashing scheme as plugin
Hi,
I want to add a new password hashing scheme as plugin and provide it for
the dovecot project, so that it will be included as optional plugin in
future releases.
Yet the plugin compiles fine and the .so file gets created.
My approach is to call the functions password_scheme_register() and
password_scheme_unregister() (src/auth/password-scheme.c) inside the
plugin's _init() and _deinit()
2017 Jan 10
2
Default hashing function for integers (DenseMapInfo.h)
> On Jan 10, 2017, at 9:36 AM, Bruce Hoult <bruce at hoult.org> wrote:
>
> Both are not very sophisticated.
> You should also look at the different MurmurHash versions, and descendants such as CityHash.
I did a few benchmark this morning, trying to tweak the hashing for pointers (as many people seem to use pointers as keys). The hash function in LLVM is quite simple, but it
2014 Feb 01
2
[LLVMdev] ADT/Hashing.h on 32-bit platforms
Hi,
Currently the hashing implementation in ADT/Hashing.h produces hash
values on 32-bit platforms that differ from the lower 32-bits of the
hash values produced on 64-bit platforms. It seems the only reason for
this difference is that the uint64_t integer seed is truncated to
size_t. Since the usage of uint64_t and size_t as types for seed values
in the implementation is somewhat
2016 May 27
0
IPv6, ULAs and FreeBSD
Kevin Oberman [2016-05-27 12:02 -0700] :
> This is fine, but why not use link-local for the VPN links? That's the
> primary reason for them. (N.B. I am not aware of your architectural
> details, and ULAs for the VPNs might be appropriate.)
Is it? I didn't know that I can use link-local addresses for the VPN
too. How do I decide between link-local or unique-local addresses for
2016 May 28
0
IPv6, ULAs and FreeBSD
Mark Tinka [2016-05-27 23:57 +0200] :
> On 27/May/16 21:02, Kevin Oberman wrote:
>
> > This is fine, but why not use link-local for the VPN links? That's
> > the primary reason for them.
>
> That's really not good advice.
>
> I'd caution against using link-local addresses for any type of
> service.
>
> Link-local addresses are used for
2016 May 28
0
IPv6, ULAs and FreeBSD
Mark Tinka [2016-05-28 14:11 +0200] :
> Why don't you have GUA IPv6 address space?
>
> Your ISP should be able to assign you a /48 or /56 prefix for you to
> use on your LAN. That's more than plenty of space.
As I wrote, I only got a /112 form my ISP. This still exceeds the amount
of addresses that I need but I decided to go for ULAs for flexibility.
Anyway, it's
2012 Feb 18
0
[LLVMdev] We need better hashing
On Fri, Feb 17, 2012 at 10:58 PM, Talin <viridia at gmail.com> wrote:
> However, I really do need an incremental hash for the various uniquing
> maps which I'm attempting to optimize. Take for example the case of
> uniquing a constant array - the key consists of a type* pointer and an
> array of constant*. Those data fields are not stored contiguously in
> memory, so I
2017 Jan 10
3
Default hashing function for integers (DenseMapInfo.h)
> On Jan 10, 2017, at 8:56 AM, Mehdi Amini <mehdi.amini at apple.com> wrote
>
> Some tests I can suggest is to replace the hash function with your favorite and:
Thanks. I’ll give it a try. It will take some time as I need to rewrite DenseMap if I want to use the Knuth multiplicative hash.
> ultimately I believe real-world impact is the best way to get a change in.
That’s
2013 Apr 13
1
[LLVMdev] Q: clang, obj-c: Hashing selectors to SEL's.
I'm trying to understand the method dispatch in objc_MsgSend.
At some point during compilation, ascii selectors are hashed
into integer SEL's. Is this hash somehow guaranteed to be unique?
If so, how? If not, how are collisions handled? Is this hashing
done during the link phase?
Any insights/pointers to the code/documentation related to this
hashing would be greatly appreciated.