Displaying 20 results from an estimated 200 matches similar to: "Extract time from irregular date and time data records"
2011 Mar 24
2
Help with creating a ts (time series) object with daily sampling values
Hi All,
I have a data set of daily measurements of river flow. I would like to
create a "ts" object from this data.
Here's a sample data set:
date <- as.Date(c(1:300), format="%Y")
year=as.numeric(format(date, format = "%Y"))
month=as.numeric(format(date, format = "%m"))
julianday=as.numeric(format(date, format = "%j"))
2010 Mar 24
2
translating SQL statements into data.table operations
I've recently stumbled across data.table, Matthew Dowle's package. I'm
impressed by the speed of the package in handling operations with large
data.frames, but am a bit overwhelmed with the syntax. I'd like to express
the SQL statement below using data.table operations rather than sqldf (which
was incredibly slow for a small subset of my financial data) or
import/export with a
2012 Feb 10
2
apply pairs function to multiple columns in a data frame
I am very new to R and programming and thank you in advance for your patience
and help with a complete novice!
I am working with a large multivariate data set that has 10 explanatory
environmental variables (e.g. temp, depth) and over 60 response variables
(each is a separate species). My data frame is set up like the simplified
version below:
JulianDay Temperature Salinity Depth Copepod
2010 Aug 20
3
rollmean help (or similar function)
I am working on a simple pilot project comparing the capability of SQL,
SAS and R to perform a rolling mean per the following instructions. I
have completed the SQL and SAS analysis, so now it's R's turn.
Calculate mean values of x (x=count) for each date in the dataset where
mean = the average count of days [t-9] through day [t-3] for each
date/illness combination.
Dataset aggpilot
2009 Nov 03
10
programación básica
Necesito algo de programación básica para resolver un problema, un
inconveniente es que intente "if", cuándo se lo aplico digamos a x <-
5 no hay drama, pero si es a leche$litros me dice que solo se toma el
primer elemento. Como pueden ver estoy re perdido.
Mi problema: los datos están en un data.frame como el siguiente
animal inicio fin control idlactancias
2009 Apr 06
1
Comparing 2 slopes of 2 regression lines
Hello everyone,
I would like to test two regression slopes:do they differ significantly?The data and commands I've used so far:
x<-8.5:32.5 #Vektor x
y<-c( NA , NA , 5.67 , 6.53 , 6.83, 7.41 , 7.93 , 8.5 , 8.86, 9.46 , 9.82 , 10 ,10.35 , 10.7 ,11.03 ,11.37 ,11.61 ,11.84, 12.12, 12.39 ,12.67 ,12.96, 13.28 ,13.47, 13.65) #Vektor y
(regression<-lm(y~x))
summary(regression)
2012 Jul 10
2
estimation of NA by predict command
Dear arun and all R users,
I will first of all try to simply define my issue..
I have data in the following format
Year Discharge
dd/mm/yyyy x
.. …
… …
There are some NA values in the discharge which I would like to predict by using “predict command”. I cant figure out the way to write the coding for that. Could you please help me on that???
I have also ,written
2011 Apr 26
1
splitting and reorganising a data.frame
Hey,
i have a question about how to reorganize a data frame in the easiest way.
my example: what would be the easiest way to bring a data.frame such like this:
----
nr height age Seed
1 1 4.51 3 301
2 15 10.89 5 301
3 29 28.72 10 301
4 43 41.74 15 301
5 57 52.70 20 301
6 71 60.92 25 301
7 2 4.55 3 303
8 16 10.92 5 303
9 30 29.07 10 303
10 44
2017 Jan 23
2
[InstCombine] rL292492 affected LoopVectorizer and caused 17.30%/11.37% perf regressions on Cortex-A53/Cortex-A15 LNT machines
Confirm there is no change in IR if the hack is disabled in the sources.
David wrote that these instructions are created by SCEV.
Are other targets affected by the changes, e.g. X86?
Kind regards,
Evgeny Astigeevich
Senior Compiler Engineer
Compilation Tools
ARM
From: Sanjay Patel [mailto:spatel at rotateright.com]
Sent: Sunday, January 22, 2017 10:45 PM
To: Evgeny Astigeevich
Cc: llvm-dev; nd
2017 Jan 22
2
[InstCombine] rL292492 affected LoopVectorizer and caused 17.30%/11.37% perf regressions on Cortex-A53/Cortex-A15 LNT machines
Thank you for information.
I’ll build clang without the hack and re-run the benchmark tomorrow.
-Evgeny
From: Sanjay Patel [mailto:spatel at rotateright.com]
Sent: Sunday, January 22, 2017 8:00 PM
To: Evgeny Astigeevich
Cc: llvm-dev; nd
Subject: Re: [InstCombine] rL292492 affected LoopVectorizer and caused 17.30%/11.37% perf regressions on Cortex-A53/Cortex-A15 LNT machines
> Do you mean to
2017 Jan 24
3
[InstCombine] rL292492 affected LoopVectorizer and caused 17.30%/11.37% perf regressions on Cortex-A53/Cortex-A15 LNT machines
Hi Sanjay,
Thank you for your analysis. It’s interesting why the x86 machine is not affected. Maybe the x86 backend is smarter than the AArch64 backend, or it might be micro-architectural differences.
I don’t mind to keep the changes on trunk.
What I’d like to see is who will/should be involved in solving the issue. What kind of help/support is needed? Should we (ARM Compilation Tools) start
2017 Jan 24
2
[InstCombine] rL292492 affected LoopVectorizer and caused 17.30%/11.37% perf regressions on Cortex-A53/Cortex-A15 LNT machines
> On Jan 23, 2017, at 3:48 PM, Sanjay Patel via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>
> All targets are likely affected in some way by the icmp+shl fold introduced with r292492. It's a basic pattern that occurs in lots of code. Did you see any perf wins on your targets with this commit?
>
> Sadly, it is also likely that many (all?) targets are negatively
2017 Jan 22
2
[InstCombine] rL292492 affected LoopVectorizer and caused 17.30%/11.37% perf regressions on Cortex-A53/Cortex-A15 LNT machines
Hi Sanjay,
The benchmark source file: http://www.llvm.org/viewvc/llvm-project/test-suite/trunk/SingleSource/Benchmarks/Shootout/sieve.c?view=markup
Clang options used to produce the initial IR: clang -DNDEBUG -O3 -DNDEBUG -mcpu=cortex-a53 -fomit-frame-pointer -O3 -DNDEBUG -w -Werror=date-time -c sieve.c -S -emit-llvm -mllvm -disable-llvm-optzns --target=aarch64-arm-linux
Opt options: opt -O3
2017 Jan 24
3
[InstCombine] rL292492 affected LoopVectorizer and caused 17.30%/11.37% perf regressions on Cortex-A53/Cortex-A15 LNT machines
> On Jan 24, 2017, at 7:18 AM, Sanjay Patel <spatel at rotateright.com> wrote:
>
>
>
> On Mon, Jan 23, 2017 at 10:53 PM, Mehdi Amini <mehdi.amini at apple.com <mailto:mehdi.amini at apple.com>> wrote:
>
>> On Jan 23, 2017, at 3:48 PM, Sanjay Patel via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>>
2012 Mar 22
2
R 2.14.1 memory management under Windows
I computed "system.time(diag(30000))" with R 2.12.0 on Fedora 13 Linux
with 4 GB RAM and with R 2.14.1 on Windows 7 with 8 GB RAM:
Linux (4 GB RAM): 0, 0.21, 0.21 -- a fifth of a second
Windows 7 (8 GB RAM): 11.37 7.47 93.19 -- over 1.5 minutes. Moreover,
during most of that time, I could not switch windows or get any response
from the system. When I first encountered this, I
2009 Apr 28
2
correlation coefficient
Hello,
I would like to get a correlation coefficient (R-squared) for my model.
I don't know how to calculate it in R.
What I've done so far:
x<-8.5:32.5 #Vektor x
y<-c(NA ,5.88 , 6.95 , 7.2 , 7.66 , 8.02 , 8.44 , 9.06, 9.65, 10.22 ,
10.63 ,11.06, 11.37, 11.91 ,12.28, 12.69 ,13.07 , 13.5 , 13.3 ,14.14 , NA , NA , NA , NA , NA) #Vektor y
2010 Sep 15
1
Difficulty creating Julian day in data frame
Hi,
I'm attempting to add a "Julian Day" column to a data frame.
Here is my code and the resulting data frame:
vic.data <- read.table("C:/VIC/data/vic.data.csv", header=F)
names(vic.data) <- c("year", "month", "day", "precip", "evap",
"runoff", "baseflow", "Tsup",
2017 Jan 20
3
[InstCombine] rL292492 affected LoopVectorizer and caused 17.30%/11.37% perf regressions on Cortex-A53/Cortex-A15 LNT machines
Hi,
We found that today's 17.30%/11.37% performance regressions in LNT SingleSource/Benchmarks/Shootout/sieve on LNT-AArch64-A53-O3__clang_DEV__aarch64 and LNT-Thumb2v7-A15-O3__clang_DEV__thumbv7 (http://llvm.org/perf/db_default/v4/nts/daily_report/2017/1/20?filter-machine-regex=aarch64%7Carm%7Cthumb%7Cgreen) are caused by changes [rL292492] in InstCombine:
https://reviews.llvm.org/D28406
2012 Sep 10
2
how to create a segplot in black and white?
Hi to all
I hope you can help me.
# I'm trying to plot the following ratio data with standard error bars
(horizontal).
ratioBiomass <- c(1.327, 0.865, 1.900, 0.992, 1.469, 1.381, 1.230,1.269,
2.411, 1.288, 1.861, 0.714, 1.341, 1.362, 1.065, 2.374)
SEratio <- c(19.28, 5.04, 0.01, 0.01, 0.90, 0.02, 0.002, 11.37,
0.004, 0.29, 0.003, 0.13, 0.21, 0.52, 1.66, 14.57)
Species <-
2017 Oct 13
2
How to define proper breaks in RFM analysis
Hey,
i want to define 3 ideal breaks (bin) for each variable one of those
variables is attached in the previous email,
i don't want to consider quartile method because quartile is not working
ideally for that data set because data distribution is non normal.
so i want you to suggest another method so that i can define 3 breaks with
the ideal interval for Recency, frequency and monetary to