Displaying 20 results from an estimated 90 matches similar to: "Testing year effects in lm()"
2009 Jul 30
1
Testing year effect in lm() ***failed first time, sending again
Dear R-helpers,
I have a linear model with a year effect (year is coded as a factor), i.e.
the parameter estimates for each level of my year variable have significant
P values (see some output below) and I am interested in testing:
a) the overall effect of year;
b) the significance of each year vis-a-vis every other year (the model
output only tests each year against the baseline year).
I'd
2005 May 19
1
logistic regression: differential importance of regressors
Hi, All. I have a logistic regression model that I have run. The
question came up: which of these regressors is more important than
another?
(I'm using Design)
Logistic Regression Model
lrm(formula = iconicgesture ~ ST + SSP + magnitude + Condition +
Expertise, data = d)
Coef S.E. Wald Z P
Intercept -3.2688 0.2854 -11.45 0.0000
ST 2.0871 0.2730 7.64
2003 Nov 29
2
Indexing ANOVA table
Hi all,
I'd like to extract a value from an ANOVA table, but experience the following
problem:
### This works:
> s.pseudo <- summary(aov(m ~ block + mix*graz,data=split1))
> s.pseudo
Df Sum Sq Mean Sq F value Pr(>F)
block 2 1114.66 557.33 4.4296 0.04192 *
mix 1 6.14 6.14 0.0488 0.82956
graz 2 1.45 0.72 0.0057 0.99427
mix:graz
2008 Feb 06
1
box.Cox.powers() warning
Dear Rlist,
Using an example in box.cox.powers() help, I have the following warning message.
example:
library(car)
>attach(Prestige)
> box.cox.powers(income)
Box-Cox Transformation to Normality
Est.Power Std.Err. Wald(Power=0) Wald(Power=1)
0.1793 0.1108 1.6179 -7.4062
L.R. test, power = 0: 2.7103 df = 1 p = 0.0997
L.R. test, power = 1: 47.261 df = 1 p = 0
2008 Aug 04
2
Howto Smooth a Curve Created with the Point Function
Hi all,
I have this figure:
http://docs.google.com/Doc?id=df5zfsj4_103rjt2v4d5
created with the following steps:
> x
[1] 90.4 57.8 77.0 103.7 55.4 217.5 68.1 85.3 152.0 113.0 97.1 89.9
[13] 68.1 83.7 77.4 34.5 104.9 170.3 88.6 88.1 108.8 77.4 85.6 82.7
[25] 81.3 108.0 49.5 71.0 85.7 99.3 203.5 275.9 51.1 84.8 16.5 72.6
[37] 160.5 158.3 136.7 140.0 98.4 116.1
2009 Oct 05
1
interpreting glmer results
Hi all,
I am trying to run a glm with mixed effects. My response variable is
number of seedlings emerging; my fixed effects are the tree species
and distance from the tree (in two classes - near and far).; my random
effect is the individual tree itself (here called Plot). The command
I've used is:
mod <- glmer(number ~ Species + distance + offset(area) + (1|Plot),
family = poisson)
2007 Jul 25
2
using contrasts on matrix regressions (using gmodels, perhaps)
Hi,
I want to test for a contrast from a regression where I am regressing the columns of a matrix. In short, the following.
X <- matrix(rnorm(50),10,5)
Y <- matrix(rnorm(50),10,5)
lm(Y~X)
Call:
lm(formula = Y ~ X)
Coefficients:
[,1] [,2] [,3] [,4] [,5]
(Intercept) 0.3350 -0.1989 -0.1932 0.7528 0.0727
X1 0.2007 -0.8505 0.0520
2000 Oct 03
3
prcomp compared to SPAD
Hi !
I've used the example given in the documentation for the prcomp function
both in R and SPAD to compare the results obtained.
Surprisingly, I do not obtain the same results for the coordinates of
the principal composantes with these two softwares.
using USArrests data I obtain with R :
> summary(prcomp(USArrests))
Importance of components:
PC1 PC2
2009 Jul 28
1
Sort a column in a dataframe
Dear Users
This is my dataset called mydata4. I want to sort the dataframe on the first
column PxMid which is basically a column with dates.
I've tried mydata4<-mydata4[order(mydata4$PxMid),] but it doesnt work. Could
it be because these are dates?
Please help I'm really stuck !!
Thank you for your time.
Regards
Meenu
PxMid EU0006MIndex.x DMSW1Curncy.x DMSW2Curncy.x DMSW3Curncy.x
1
2010 Mar 19
0
Different results from survreg with version 2.6.1 and 2.10.1
---------------------------- Original Message ----------------------------
Subject: Different results from survreg with version 2.6.1 and 2.10.1
From: nathalcs at ulrik.uio.no
Date: Fri, March 19, 2010 16:00
To: r-help at r-project.org
--------------------------------------------------------------------------
Dear all
I'm using survreg command in package survival.
2011 Jul 21
1
Select Random Rows from a dataframe
Hi all,
I have a dataframe of behavioral observations from 360 fish, each with 241 observation points(rows), which looks like this:
> head(d)
fish treatment tank trial video tid pid ang.chg abs.ac t len vel d2p x y
1 1 3 1 1 1 1 1 NA NA 0.0 0.000 NA NA 5.169 9.617
2
2017 Nov 10
1
How to create separate legend for each plot in the function of facet_wrap in ggplot2?
Hi R users,
I need to create more than 20 figures (one for each group) in one page. I
have a common legend for 20 figures using the facet_wrap. However the
range of the values among the groups are very wide. For example one group
has the value of 0 to 3, but the values of some of the groups has ranged
from 0 to 20 so that when I used a single common legend for all 20 figures,
I could not display
2010 Nov 06
10
Apparent SAS HBA failure-- now what?
My setup: A SuperMicro 24-drive chassis with Intel dual-processor
motherboard, three LSI SAS3081E controllers, and 24 SATA 2TB hard drives,
divided into three pools with each pool a single eight-disk RAID-Z2. (Boot
is an SSD connected to motherboard SATA.)
This morning I got a cheerful email from my monitoring script: "Zchecker has
discovered a problem on bigdawg." The full output is
2005 Feb 11
0
time series questions?
Two time series questions:
FITTING TRANSFER FUNCTIONS WITH LAGS: Consider the following toy example:
> dates <- paste(11:21, "/01/2005", sep="")
> Dates <- as.Date(dates, "%d/%m/%Y")
> set.seed(1)
> DF <- data.frame(date=Dates, y=rnorm(11), x=rnorm(11, 3))
> arima(DF$y, c(1,0,0), xreg=lag(DF$x, 1))
ar1 intercept lag(DF$x,
2011 Jun 02
1
an efficient way to calculate correlation matrix
Dear all,
I have a problem. I have m variables each of which has n observations. I want to
calculate pairwise correlation among the m variables and store the values in a m
x m matrix. It is extremely slow to use nested 'for' loops if m and n are large.
Is there any efficient alternative to do this? Many thanks for your
suggestions!!
Bill
2012 Apr 22
1
Survreg
Hi all,
I am trying to run Weibull PH model in R.
Assume in the data set I have x1 a continuous variable and x2 a
categorical variable with two classes (0= sick and 1= healthy). I fit the
model in the following way.
Test=survreg(Surv(time,cens)~ x1+x2,dist="weibull")
My questions are
1. Is it Weibull PH model or Weibull AFT model?
Call:
survreg(formula = Surv(time, delta) ~ x1
2010 Jan 19
1
splitting a factor in an analysis of deviance table (negative binomial model)
Dears useRs,
I have 2 factors, (for the sake of explanation - A and B), with 4 levels each. I've already fitted a negative binomial generalized linear model to my data, and now I need to split the factors in two distinct analysis of deviance table:
- A within B1, A within B2, A within B3 and A within B4
- B within A1, B within A2, B within A3 and B within A4
Here is a code that illustrates
2006 Sep 18
2
problems in sourcing R script
Dear list,
First my information:
platform i386-pc-linux-gnu
arch i386
os linux-gnu
system i386, linux-gnu
status
major 2
minor 3.1
year 2006
month 06
day 01
svn rev 38247
language R
version.string Version 2.3.1 (2006-06-01)
Now my question:
How is it possible that a command in an R script is not
2013 Mar 28
0
using cvlm to do cross-validation
Hello,
I did a cross-validation using cvlm from DAAG package but wasn't sure how to assess the result. Does this result means my model is a good model?
I understand that the overall ms is the mean of sum of squares. But is 0.0987 a good number? The response (i.e. gailRel5yr) has min,1st Quantile, median, mean and 3rd Quantile, and max as follows: (0.462, 0.628, 0.806, 0.896, 1.000, 2.400) ?
2016 Aug 11
3
Comparación de probabilidades de supervivencia en R
Hola, Manuel,
No entiendo tu pregunta (la repito aqui para que sea mas explicito):
hay alguna forma de comparar la probabilidad de
supervivencias (en este caso anual) entre grupos sin utilizar un
chi-cuadrado y un valor de P. Entiendo que lo que hace survdiff es comparar
las curvas de supervivencia, pero yo quiero comparar la probabilidad de
supervivencia entre grupos al final del estudio.
Con