Displaying 17 results from an estimated 17 matches for "schatzi".
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tchatzi
2011 May 05
6
Averaging uneven measurements by time with uneven numbers of measurements
I have a new device that takes measurements anywhere from every second, to
every 15 minutes (depending on changes). The matrix has a date, time and Y
column (Y is the measurement). For three days it is 25,000 rows. How do I
average the measurements by every 30 minutes so my matrix is 48 rows per
day? I have been working on this and cannot figure out a simple method. Any
ideas? Thank you.
-----
In
2011 May 09
2
Round down to earliest hour or half hour
I have times and would like to round down to the earliest 30 minute
increment. For instance, a time of
2011-04-28 09:02:00
(the as.numeric value = 1303999320)
I would like it to be rounded down to:
2011-04-28 09:00:00
(the as.numeric value = 1303999200)
Any ideas of how to do this?
-----
In theory, practice and theory are the same. In practice, they are not - Albert Einstein
--
View this
2011 Oct 26
6
sometimes removing NAs from code
Sometimes I have NA values within specific columns of a dataframe (in this
example, the first two columns can have NAs). If there are NA values, I
would like them to be removed.
I have been using the code:
y<-c(NA,5,4,2,5,6,NA)
z<-c(NA,3,4,NA,1,3,7)
x<-1:7
adata<-data.frame(y,z,x)
adata<-adata[-which(apply(adata[,1:2],1,function(x)any(is.na(x)))),]
This works well if there are NA
2011 Apr 18
3
Power Analysis
I am trying to do a power analysis to get the number of replicas per
treatment.
If I try to get the power it works just fine:
setn=c(2,3)
sdx=c(1.19,4.35)
power.t.test(n = setn, delta = 13.5, sd = sdx, sig.level = 0.05,power =
NULL)
If I go the other way to obtain the "n" I have problems.
sdx=c(1.19,4.35)
pow=c(.8,.8)
power.t.test(n = NULL, delta = 13.5, sd = sdx, sig.level = 0.05,
2011 May 10
2
need to delete by time, not date
I have a matrix where one column has a date and another column has a time. I
need to delete all times before 6am. I had combined the Date and Time column
into DateTime.
Mat1:
Weight Date Time
7.6 04/28/11 09:03
8.4 04/29/11 03:11
8.6 04/29/11 05:32
8.6 04/29/11 09:53
1.4 05/01/11 19:52
I tried just picking up the time:
as.POSIXct(Mat1$Time, format = "%H:%M")
but
2011 Feb 08
2
Plot where points are treatment letter
I would like to create a plot of y vs x with different treatments where the
points are actually the letter of the treatment. Here is the code:
A<-as.matrix(rnorm(10,10))
B<-as.matrix(rnorm(10,9.5))
C<-as.matrix(rnorm(10,10.5))
Y<-as.matrix(rnorm(30,13))
X<-rbind(A,B,C)
nA<-matrix("A",10,1)
nB<-matrix("B",10,1)
nC<-matrix("C",10,1)
2006 Jul 18
4
How can I extract information from list which class is nls
Hello!
I work with :
R : Copyright 2006, The R Foundation for
Statistical Computing
Version 2.3.1 (2006-06-01)
On Windows XP Professional (Version 2002) SP2.
At this moment I use the function "nls" combined
with a selfStar model (SSmicmen, related to
Michaelis-Menten equation, and provided by the
"stats" package).
When I realise the following operation (cf. p 59
of the
2011 May 12
3
assigning creating missing rows and values
I have a dataset where I have missing times (11:00 and 16:00). I would like
the outputs to include the missing time so that the final time vector looks
like "realt" and has the previous time's value. Ex. If meas at time 15:30 is
0.45, then the meas for time 16:00 will also be 0.45.
meas are the measurements and times are the times at which they were taken.
meas<-runif(18)
2011 May 12
1
separate date and time
I have a combined date and time. I would like to separate them out into two
columns so I can do things such as take the mean by time across all dates.
meas<-runif(435)
nTime<-seq(1303975800, 1304757000, 1800)
nDateT<-as.POSIXct(nTime, origin="1970-01-01")
mat1<-cbind(nDateT,meas)
means1<- aggregate(mat1$meas, list(nDateT), mean)
This doesn't do anything as each day
2011 May 13
1
Plots: I've deleted axes, now to delete space
I am plotting 28 plots on one screen:
par(mfrow=c(4,7))
for (i in 1:28) {
a<-seq(1,3,1)
plot(a,a, ann=FALSE)
}
I want a main title for all the plots (I tried using main but that doesn't
work). I deleted the axes, but am not sure how to delete the space. There
are such large margins between plots so the plots themselves are very small.
If I delete the margins I can leave them all on one
2020 Aug 01
4
Boot failed on latest CentOS 7 update
Totally and completely on my HP microfiber. Wouldn't get past anything to
even get me into the grub menu. NOT AMUSED!
_______________________
Kay Schenk
2006 Apr 11
3
ext3 filesystem corruption
Hi -
We have had 3 rather major occurances of ext3 filesystem corruption
lately,
i.e. so bad we couldn't event mount, and fsck didn't help.
I am looking for pointers, that could help us investigate the root
cause.
In general...
We are running RedHat WS 3 Update 6, 2.4.21-40.2.ELsmp or
2.4.21-37.ELsmp
We have a small SAN system that looks like this
2011 Nov 03
1
For loop to cycle through datasets of differing lengths
I have encountered this problem on several occasions and am not sure how to
handle it. I use for-loops to cycle through datasets. When each dataset is
of equal length, it works fine as I can combine the datasets and have each
loop pick up a different column, but when the datasets are differing
lengths, I am struggling. Here is an example:
A<-1:10
B<-1:15
C<-1:18
2011 Feb 28
3
nls not solving
I am running the following nls equation. I tried it with data that excel was
fitting and got the error:
singular gradient matrix at initial parameter estimates
I thought it was due to a low number of points (6), but when I create a
dataset, I get the same problem. If I remove the parameter "a," then it can
find a solution. Does anyone know what I can do to fit this model?
2011 Sep 12
6
barplot in hexagram layout
dev.new(width=6, height=1.5,mar=c(0,0,0,0))
par(mfrow=c(1,1),mar=c(.5, .5, 1.5, .5), oma=c(.4, 0,.5, 0))
barplot(c(1,1,1,1,1,1),col=c("blue","purple","red","green","orange","yellow"),
axes = FALSE)
I have a barplot that returns six colors in a line. I would like to get the
same six color blocks in a hexagram layout (if it were a clock,
2020 Aug 02
0
Boot failed on latest CentOS 7 update
And for whatever reason, both my centos 7 and 8 survived this apparently
with flying colors. Actually, this is out of character for how fate has
been dealing the cards recently.
I'm very leary about rebooting either, now, though.
On Sat, Aug 1, 2020 at 12:50 PM Kay Schenk <kay.schenk at gmail.com> wrote:
> Totally and completely on my HP microfiber. Wouldn't get past
2011 Oct 21
0
nls making R "not responding"
Here is the code I am running:
library(nls2)
modeltest<- function(A,mu,l,b,thour){
out<-vector(length=length(thour))
for (i in 1:length(thour)) {
out[i]<-b+A/(1+exp(4*mu/A*(l-thour[i])+2))
}
return(out)
}
A=1.3
mu=.22
l = 15
b = .07
thour = 1:25
Yvals<-modeltest(A,mu,l,b,thour)-.125+runif(25)/4
st2 <- expand.grid(A = seq(0.1, 1.6,.5), mu = seq(0.01, .41,.1), l=1, b
=seq(0,.6,.3))