Displaying 20 results from an estimated 6000 matches similar to: "Z test and proportions"
2008 Jun 20
2
Problems with basic loop
I'm having trouble creating a looping variable and i can't see wher ethe
problem arises from any hep gratfully appreciated
First create a table
x<-table(SURVEY$n_0,exposed)
> x
exposed
False True
Under 16 24 1
16-19 68 9
20-24 190 37
25-34 555 204
35-44 330 87
45-54 198 65
55-64 67 35
65+
2008 Oct 24
1
pwr.2p2n.test when the ratio of n1/n2 is known
Hi,
I am trying to do a power calculation for a difference in proportions
test where I want to estimate the sample size required. I know (well
estimate) that group one (n1) is 10% of the population and group 2 (n2)
is 90% of the population. I know the effect size (h). pwr.2p2n.test
only allows one variable to be left null whereas I would like both n1
and n2 to be determined where I know there
2008 Dec 16
1
pwr.prop.test and continuity correction
Hi,
I am trying to sort out a discrepancy between power calculations results
between me and another statistician. I use R but I am not sure what she
uses. It is on the proportions test and so I have been using
pwr.prop.test. I think I have tracked the problem down to pwr.prop.test
not using the continuity correction for the test (I did this by using
the java applet from
2010 Sep 21
2
Trouble installing pwr package
Hi all,
I'm having trouble getting access to the pwr. This is on Ubuntu Lucid Lynx,
64 bit.
I'm installing pwr via packages.install('pwr'), and loading it via
library(pwr), both of which appear successful.
Strangely, I never get access to the pwr object in R.
I tried installing it to /usr/local/lib/R/site-library and
~/R/x86_64-pc-linux-gnu-library.
I also tried installing it
2008 Jun 06
2
Merging two dataframes
Hi All,
Newbie question for you all but i have been looking at the archieves and the
help dtuff to get a rough idea of what i want to do
I would like to merge two dataframes together based on a keyed variable in
one dataframe linking to the other dataframe. Only some of the cases will
match but i would like to keep the others as well.
My dataframes have 67 and 28 cases respectively and i would
2009 Sep 15
2
Viewing Function Code
Hi All,
I'd like to see the function code behind the barplots2() function in the
gplots package, however i come across a bit of a stumbling block of a hidden
function, can anyone help?
> library(gplots)
> methods(barplot2)
[1] barplot2.default*
Non-visible functions are asterisked
> barplot2
function (height, ...)
UseMethod("barplot2")
<environment:
2008 Jun 17
2
Calling functions
Another newbie question.
I've written a function and saved the file as Xtabs.R, in a central place on
a network so others will be able ot use the function,
My question is how do i call this function?
I've tried to chance the working directory, and tried to load it via;
> library(Xtabs, lib.loc="//filer/common/technical/surveys/R_test")
but neither seem to work? the function
2014 Dec 23
2
[PATCH V2 2/4] pwr: make nouveau_pwr_pgob() non-static
On 12/22/2014 05:11 PM, Vince Hsu wrote:
> The platform device does not use the common nouveau_pwr_init() to initialize
> the PWR, but it does need the .prob() be assigned to avoid NULL pointer
> dereference in graph/nve4.c.
s/prob/pgob/ :-(
Will fix in next version.
>
> Signed-off-by: Vince Hsu <vinceh at nvidia.com>
> ---
>
> v2: this patch is added since v2. (v1
2012 Mar 28
1
binomial sample size calculation
Hi everyone.
I need to do a sample size calculation for a one sample based on a CI interval of +- 5% of the proportion, we expect to have a rate of 0.07 based on similar studies. I have looked at the pwr-package as well as the power.prop.test function, but I can't see how to make either do what I need. Could anyone point me to a function, or explain how to do this will the functions in pwr?
2008 Dec 05
1
Loop swith String replacement
Hi All,
I'm trying to split my dataset, into multiple datasets that i'll analyse
later, i wanted to do this dynamically as i might need to rerun the code
later.
I was looking at doing this via a loop, (Are other methods more appropriate?
Would a function be better?)
However i'm not sure in R how do do string replacement within the loop in
order to create unique dataset names based on
2009 Aug 25
1
Help with nls and error messages singular gradient
Hi All,
I'm trying to run nls on the data from the study by Marske (Biochemical
Oxygen Demand Interpretation Using Sum of Squares Surface. M.S. thesis,
University of Wisconsin, Madison, 1967) and was reported in Bates and Watts
(1988).
Data is as follows, (stored as mydata)
time bod
1 1 0.47
2 2 0.74
3 3 1.17
4 4 1.42
5 5 1.60
6 7 1.84
7 9 2.19
8 11 2.17
I then
2012 Feb 10
3
problem subsetting data frame with variable instead of constant
Hello,
I've encountered a very weird issue with the method subset(), or maybe this
is something I don't know about said method that when you're subsetting
based on the columns of a data frame you can only use constants (0.1, 2.3,
2.2) instead of variables?
Here's a look at my data frame called 'ea.cad.pwr':
*>ea.ca.pwr[1:5,]
MAF OR POWER
1 0.02 0.01 0.9999
2 0.02
2004 Jun 14
2
Member Server in Active Directory
I'm trying to join a Samba 3.0.4 (compiled from source on Debian) to an
Active Directory as a member server. I believe Kerberos is configured
correctly as kinit creates a ticket for the realm. Executables appear to have
support for Kerberos and LDAP (smbd -b | grep KRB and grep LDAP) return OK.
When I try to join the AD with
net ads join -U myadminusername
I'm prompted for my
2008 Dec 31
3
Paste in a FOR loop
Hi All,
I've been having a little trouble using R2HTML and a loop, but can't figure
out where the problem lies, any hints gratefully received.
My code at the minute, (Which does work) is in the following:
library(R2HTML)
HTMLStart(outdir =
file.path("C://Example_work","R_projects","Dynamic_creative"),filename =
"RMDC_mockup",Title="Mock up for
2008 Aug 05
2
Selecting Variables
Hi All,
i have a dataset that i want to dynamically inspect for the number of
variables that start with "Exposure_" and then for these count the entries
across each case i.e
ID Exposure_1 Exposure_2 Exposure_3
1 y y y
2 y y -
3 y - -
So the corresponding new variables
2011 Dec 17
1
properly check for _DSM function support and Optimus support for vga_switcheroo
Hello guys,
I've prepared a patch based on my findings for the bbswitch module
(https://github.com/Lekensteyn/acpi-stuff/tree/master/bbswitch). This adds
a proper
check whether a _DSM function is supported or not and make OFF / ON for
vga_switcheroo work for nVidia Optimus models. The patch is based against
the
mainline kernel.
It has been tested on my Clevo B7130 laptop running kernel 3.2
2009 Aug 13
1
power.t.test (PR#13891)
Full_Name: Michael J. Lew
Version: R version 2.9.1 (2009-06-26)
OS: OS X
Submission from: (NULL) (210.49.195.149)
The default function power.t.test gives inaccurate values, particularly with
large sig.level.
There are two reasons for me to propose that power.t.test is inaccurate:
1. When sig.level approaches 1, so should the power. However,
2013 Oct 03
2
SSweibull() : problems with step factor and singular gradient
SSweibull() : problems with step factor and singular gradient
Hello
I am working with growth data of ~4000 tree seedlings and trying to fit non-linear Weibull growth curves through the data of each plant. Since they differ a lot in their shape, initial parameters cannot be set for all plants. That’s why I use the self-starting function SSweibull().
However, I often got two error messages:
2016 Oct 11
2
Unable to find driver for a supported device
Hello everyone,
I have a Tripp-Lite UPS (smart1500rmxl2ua) I'm trying to get working with nut.
This is a FreeBSD 10.3 box. I've tried using the usbhid-ups<http://networkupstools.org/docs/man/usbhid-ups.html> driver but everytime I try to start up nut, I get this:
# upsdrvctl start
Network UPS Tools - UPS driver controller 2.7.4
Network UPS Tools - Generic HID driver 0.41 (2.7.4)
2006 Mar 08
1
power and sample size for a GLM with Poisson response variable
Craig, Thanks for your follow-up note on using the asypow package. My
problem was not only constructing the "constraints" vector but, for my
particular situation (Poisson regression, two groups, sample sizes of
(1081,3180), I get very different results using asypow package compared
to my other (home grown) approaches.
library(asypow)
pois.mean<-c(0.0065,0.0003)
info.pois <-