Displaying 20 results from an estimated 140 matches similar to: "Problem with diff(strptime(..."
2010 Dec 30
2
optim and singularity
Hello,
I was unable to find clues to my problem in ?optim. Using the data and code
below, I get an error ("system is exactly singular") when a particular line
of code is left in, but have found that 'optim' works when I comment it out.
The line of code in question is after the closeAllConnections() line of code
and contains a call to "na.approx" from the zoo package.
2010 Dec 22
0
adjust secondary y-axis bounds to minimize visual residuals
Hello,
I'm plotting two sets of data referenced to either the left or right y-axes.
The first, water table depth (blue circles), is plotted on the left y-axis
in reverse order (0 at the top) as this is more intuitive when thinking in
terms of depth. The second is electrical conductance (a surrogate for
salinity), and is referenced to the right y-axis. The data and plot
commands follow
2018 Apr 25
2
Wanted: WebRTC tutorial
On 04/24/2018 09:08 AM, Matt Fredrickson wrote:
> On Tue, Apr 24, 2018 at 10:54 AM, Bruce Ferrell <bferrell at baywinds.org> wrote:
>> A while back (last year maybe?), there was a Digium blog post on setting up
>> WebRTC.
>>
>> I was never able to get that working.
>>
>> I was working with Asterisk 15 on a RHEL derived distro and had no idea of
>>
2011 Jan 26
2
applying a set of rules to each row
All,
I would like to apply a set of rules to each row of the sample data set
below. The rule sets are the guidelines for determining an individual's
date for retirement eligibility. The rules are found in this document,
http://www.opm.gov/feddata/RetirementPaperFinal_v4.pdf. I am only
interested in the top two categories for retirement eligibility, the
CSRS and FERS plans.
The data set has
2018 Jan 15
1
Time-dependent coefficients in a Cox model with categorical variants
Suppose I have a dataset contain three variants, looks like
> head(dta)
Sex tumorsize Histology time status
0 1.5 2 12.1000 0
1 1.8 1 38.4000 0
.....................
Sex: 1 for male; 0 for female., two levels
Histology: 1 for SqCC; 2 for High risk AC; 3 for low risk AC,
2007 Sep 24
2
Calculate difference between dates in years
Hello,
I would like to be able to calculate the age of someone at a particular
date. Both dates are date objects. Here is what I have come up with:
floor(as.numeric(sampleInfo$Date.of.DIAGNOSIS-sampleInfo$Date.of.birth)/365.25)
Is this the best approach? or is there an inbuilt function? I have
looked at difftime but that does not seem to allow output in years.
Many thanks
Dan
--
2007 Oct 25
1
Strange behavior with time-series x-axis
I recently called plot(x,y) where x was an array of POSIXct timestamps,
and was pleasantly surprised that it produced a nice plot right out of
the box:
z <- as.POSIXct(c("2006-10-26 08:00:00 EDT","2007-10-25 12:00:00 EDT"))
x <- seq(z[1],z[2],len=100)
y <- 1:100
plot(x,y,type="l")
The X axis had nice labels, one tick mark every other month. (Plotting
on
2012 Nov 27
4
Fitting and plotting a coxph with survfit, package(surv)
Hi Dear R-users
I have a database with 18000 observations and 20 variables. I am running
cox regression on five variables and trying to use survfit to plot the
survival based on a specific variable without success.
Lets say I have the following coxph:
>library(survival)
>fit <- coxph(Surv(futime, fustat) ~ age + rx, data = ovarian)
>fit
what I am trying to do is plot a survival
2010 Nov 24
2
Is there an equivalent to predict(..., type="linear") of a Proportional hazard model for a Cox model instead?
Hi all,
Is there an equivalent to predict(...,type="linear") of a Proportional hazard
model for a Cox model instead?
For example, the Figure 13.12 in MASS (p384) is produced by:
(aids.ps <- survreg(Surv(survtime + 0.9, status) ~ state + T.categ +
pspline(age, df=6), data = Aidsp))
zz <- predict(aids.ps, data.frame(state = factor(rep("NSW", 83), levels =
2009 Mar 30
1
Possible bug in summary.survfit - 'scale' argument ignored?
Hi all,
Using:
R version 2.8.1 Patched (2009-03-07 r48068)
on OSX (10.5.6) with survival version:
Version: 2.35-3
Date: 2009-02-10
I get the following using the first example in ?summary.survfit:
> summary( survfit( Surv(futime, fustat)~1, data=ovarian))
Call: survfit(formula = Surv(futime, fustat) ~ 1, data = ovarian)
time n.risk n.event survival
2006 Aug 17
1
putting the mark for censored time on 1-KM curve or competing risk curve
Hi All,
I'm trying to figure out the cumulative incidence curve in R in some
limited time. I found in package "cmprsk", the command "plot.cuminc" can
get this curve. But I noticed that there is no mark for the censored
time there, comparing with the KM curve by "plot.survfit". Here are my
codes (attached is the data):
----------------
2011 Jul 14
1
glm() scale parameters and predicted Values
In glm() you can use the summary() function to recover the shape parameter (the reciprocal of the dispersion parameter). How do you recover the scale parameter? Also, in the given example, how I estimate and save the geometric mean of the predicted values? For a simple model you can use fitted() or predicted() functions. I will appreciate any help.
?
?
?
#Call required R packages
require(plyr)?
2009 Jan 19
1
further notes on model.frame issue
This is a follow-up on my note of Saturday. Let me start with two important
clarifications
- I think this would be a nice addition, but I've had exactly one use for it
in the 15+ years of developing the survival package.
- I have a work around for the current case.
Prioritize accordingly.
The ideal would be to change survexp as follows:
fit <- survexp( ~ gender,
2018 Mar 18
0
rdwd package error: invalid file argument raised by readDWD
Hi:
I tried to download germany' historical weather data with rdwd package.
However, when I tried to read downloaded data (1080 txt file in total) with
readDWD function, but R raised an error down below:
library(rdwd)
ftpURL <- selectDWD(name = "", exactmatch = TRUE,
res="monthly",
var="kl", per="historical",
2011 May 14
2
changing the day of the week in dates format
Dear all,
I have a question related to the POSIXlt function in R.
I have a set of dates and times, for exmaple:
startx <- as.POSIXct("2011-01-01 00:00:00")
finx <- as.POSIXct("2011-12-31 00:00:00")
daysx<- seq(startx, finx, by="24 hours")
I
want to change the dates of all the days falling on a Saturday to the
next working day (i.e. Monday). So I
2011 May 26
5
Survival: pyears and ratetable: expected events
Dear all,
I am having a (really) hard time getting pyears to work together with a
ratetable to give me the number of expected events (deaths).
I have the following data:
dos, date of surgery, as.Date
dof, date of last follow-up, as.Date
dos, date of surgery, as.Date
sex, gender, as.factor (female,male)
ev, event(death), 0= censored at time point dof, 1=death at time point dof
Could someone
2005 Aug 19
2
Handling dates
I have a problem with some functions handling dates, in packages 'date' and
'survival' (they seem to be identical). For instance, from the documentation,
--------------------
mdy.date {survival}
R Documentation
Convert to Julian Dates
Description
Given a month, day, and year, returns the number of days since January 1, 1960.
Usage
mdy.date(month, day, year, nineteen = TRUE,
2011 Nov 07
2
Problem working with dates
Hello All,
I've been reading books about R for awhile now and am in the process of replicating the SAS analyses from an old report. I want to be sure that I can do all the things I need to in R before using it in my daily work.
So far, I've managed to read in all my data and have done some data manipulation. I'm having trouble with fixing an error in a date variable though, and was
2005 Dec 20
2
Time data
Dear All, I wonder how to compute the age from the date of birth and the date of examination. Suppose that have the following data:
df <- as.data.frame(rbind(c(1,"10/08/1950","15/03/1998"), c(1,"10/08/1950","20/07/1998"), c(1,"10/08/1950","23/10/1998")))
names(df) <- c("ID", "date_birth",
2005 Dec 18
13
calculate age based on DoB
Hi,
I wrote a little helper that calulates someone''s age based on his/her
date of birth.
def age(dob)
diff = Date.today - dob
age = (diff / 365.25).floor
age.to_s
end
It works fine, but it''s not completely accurate as it just takes the
average days in a year. It should be able to calculate this more
accurately, right? I can''t work it out