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On November 6, 2016 8
Perhaps the C function Rf_logspace_sum(double *x, int n) would help in
computing log(b). It computes log(sum(exp(x_i))) for i in 1..n, avoiding
unnecessary under- and overflow.
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Sun, Nov 6, 2016 at 5:25 PM, Rolf Turner wrote:
> On 07/11/16 13:07,
To whom it may concerns,
We encountered stack overflow issues when we implemented DFS(depth first
search) algorithm on a directed graph having 800,000+ vertices and millions of
edges. The purpose of running DFS is to use Kosaraju Algorithm to calculate
the size of SCC(strongly connected compon
On 07/11/16 15:46, Charles C. Berry wrote:
On Mon, 7 Nov 2016, Rolf Turner wrote:
On 07/11/16 13:07, William Dunlap wrote:
Have you tried reparameterizing, using logb (=log(b)) instead of b?
Uh, no. I don't think that that makes any sense in my context.
The "b" values are probabilities and
On Mon, 7 Nov 2016, Rolf Turner wrote:
On 07/11/16 13:07, William Dunlap wrote:
Have you tried reparameterizing, using logb (=log(b)) instead of b?
Uh, no. I don't think that that makes any sense in my context.
The "b" values are probabilities and must satisfy a "sum-to-1" constraint.
To a
On 07/11/16 14:14, ProfJCNash wrote:
Rolf, What optimizers did you try? There are a few in the optimrx package on
R-forge that handle bounds, and it may be
useful to set bounds in this case. Transformations using log or exp can be
helpful if done carefully, but as you note,
they can make the
On 07/11/16 13:07, William Dunlap wrote:
Have you tried reparameterizing, using logb (=log(b)) instead of b?
Uh, no. I don't think that that makes any sense in my context.
The "b" values are probabilities and must satisfy a "sum-to-1"
constraint. To accommodate this constraint I re-parametr
Rolf, What optimizers did you try? There are a few in the optimrx package on
R-forge that handle bounds, and it may be
useful to set bounds in this case. Transformations using log or exp can be
helpful if done carefully, but as you note,
they can make the function more difficult to optimize.
Be
On 06/11/2016 12:25 PM, Joshua Banta wrote:
Dear everyone,
Please consider the following code, which I am using to make a custom text
file. (I need to build the text file line-by-line like this for some
idiosyncratic reasons that I will not get into here. But basically the real
text file I am
Hi Joshua,
Use Notepad++. It will also convert the linefeed EOLs to CR/LF.
Jim
On Mon, Nov 7, 2016 at 4:25 AM, Joshua Banta wrote:
> Dear everyone,
>
> Please consider the following code, which I am using to make a custom text
> file. (I need to build the text file line-by-line like this for so
Dear everyone,
Please consider the following code, which I am using to make a custom text
file. (I need to build the text file line-by-line like this for some
idiosyncratic reasons that I will not get into here. But basically the real
text file I am making is longer and more complicated than th
Thank you Bert, Jeff and David for great answers.
Let me provide more context to clarify the question:
- I am running this on a large server (512GB), so the data still fits
into memory (and I also know how to process in chunks if necessary)
- I agree that DBMS and other software would me better s
Have you tried reparameterizing, using logb (=log(b)) instead of b?
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Sun, Nov 6, 2016 at 1:17 PM, Rolf Turner wrote:
>
> I am trying to deal with a maximisation problem in which it is possible
> for the objective function to (quite legitimately) re
Note that in the OP's example c.Date is never invoked. c.Date is called if
.combine
calls c rather than if .combine is c:
> library(zoo)
> trace(c.Date, quote(print(sys.call(
Tracing function "c.Date" in package "base"
[1] "c.Date"
> foreach(i=1:10003, .combine=c) %do% { as.Date(i) }
[1]
On 06/11/2016 5:02 PM, Jim Lemon wrote:
hi James,
I think you have to have a starting date ("origin") for as.Date to
convert numbers to dates.
That's true with the function in the base package, but the zoo package
also has an as.Date() function, which defaults the origin to
"1970-01-01". If
hi James,
I think you have to have a starting date ("origin") for as.Date to
convert numbers to dates.
Jim
On Sun, Nov 6, 2016 at 12:10 PM, James Hirschorn
wrote:
> This seemed odd so I wanted to check:
>
> > x <- foreach(i=1:10100, .combine='c') %do% { as.Date(i) }
>
> yields a numeric vec
Hi Lucas,
This is a rough outline of something I programmed years ago for data
cleaning (that was programmed in C). The basic idea is to read the
file line by line and check for a problem (in the initial application
this was a discrepancy between two lines that were supposed to be
identical). Here,
I am trying to deal with a maximisation problem in which it is possible
for the objective function to (quite legitimately) return the value
-Inf, which causes the numerical optimisers that I have tried to fall over.
The -Inf values arise from expressions of the form "a * log(b)", with b
= 0.
Dear R users,
If you use quantmod::GetSymbols to download financial data from yahoo or
google finance, you might find my new package *BatchGetSymbols* very
useful. It no only downloads data for multiple tickers but also organizes
it in an efficient way, making it easy to use dplyr and ggplot2 in
> On Nov 6, 2016, at 5:36 AM, Lucas Ferreira Mation
> wrote:
>
> I have some large .txt files about ~100GB containing a dataset in fixed
> width file. This contains some errors:
> - character characters in column that are supposed to be numeric,
> - invalid characters
> - rows with too many cha
?readLines ... given the large size of file you may need to process chunks by
specifying a file connection rather than a character string file name and using
the "n" argument.
?grepl
?Extract
?tools::showNonASCII
There are many ways for data to be corrupted... in particular when invalid
cha
Hello,
Somebody would indicate the correct way to use the option the
fontchooser widget into tcltk package (in R-devel, Tcl 8.6) ?
I tried to use as other traditional widgets but no success. (code below)
Thanks
Cleber
> tt <- tktoplevel(); but <- ttkbutton( tt, text='Test'); tcl('pack', but )
>
I have some large .txt files about ~100GB containing a dataset in fixed
width file. This contains some errors:
- character characters in column that are supposed to be numeric,
- invalid characters
- rows with too many characters, possibly due to invalid characters or some
missing end of line chara
> On Nov 6, 2016, at 6:10 AM, Jeff Newmiller wrote:
>
> I am not aware of a "-1" option for R CMD INSTALL [1]. Nor do I have a
> Macintosh.
It compiles from the MacGUI console using an ordinary call (no extra
environment variables need be set) to install.packages, and then loads without
err
I am not aware of a "-1" option for R CMD INSTALL [1]. Nor do I have a
Macintosh.
Do be prepared to keep reading the documentation once you get past this point,
as the whole reason you are doing this is that the original maintainer chose to
not fix whatever problems existed in that package, an
Hi Jeff,
Many thanks for your reply.I know that R packages can be downloaded as "tar.gz"
file for Mac OS X from CRAN sources. I have found on Internet that the command
is the following :
R CMD INSTALL -1 rlme_0.4.tar.gz
When I run that command on my R console, I get an error as you can read he
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