Re: [R] lm and anova

2011-05-12 Thread Paul Chatfield
anova uses sequential sums of squares (type 1), summary adjusted sums of squares (type 3) Take for example the first line of each output. In summary this tests whether vole1 is needed ASSUMING volelag and year are already in the model (conclusion would then be: it isn't needed p=.89). Whereas

[R] All other variables in upper scope arg for stepAIC

2010-10-21 Thread Paul Chatfield
Hi - I am trying to substitute for the_other_y in the code below. I want y2 and y3 to be there when i is 1, y1 and y3 to be there when i is 2 and y1 and y2 to be there when i is 3. I'm sure it's to do with what format the data should be in and I've tried alldata[,-i], but it fits all the

[R] Referencing factor name

2010-09-22 Thread Paul Chatfield
Simple problem - I want the ylab to automatically pick up x1 rather than having to define x1 in the plot statement. x1-c(1.2,2,3);x2-c(1,2.1,2.6) y-x1 plot(1:3,y, ylab=x1) There must be a way of accessing the name x1 somehow, but unfortunately I don't know how to search for it. Any help

Re: [R] A question about conducting crossed random effects in R

2010-07-07 Thread Paul Chatfield
There is a mixed effects e-mail list you might want to join for more in depth discussion of these topics - you can subscribe here https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models. In general the format for crossed effects would be lmer(y~f1+f2+(1|r1)+(1|r2)) where f1, f2 are fixed

Re: [R] information reduction-database management question

2010-07-06 Thread Paul Chatfield
If you redefine your NAs as below to be detected as some arbitrary large number, then the code should work through. Any 5's left in your dataset can be replaced just as easily by NAs again. Not elegant, but effective. site - c(s1, s1, s1, s2,s2, s2) pref - c(1, 2, 3, 1, 2, 3) R1 - c(NA, NA, 1,

Re: [R] A question about conducting crossed random effects in R

2010-07-06 Thread Paul Chatfield
Sounds distinctly like an assignment you've been set for which we wouldn't help. All I'll say is crossed random effects can be dealt with effectively in lmer. See that for more. -- View this message in context:

Re: [R] information reduction-database management question

2010-07-06 Thread Paul Chatfield
July 2010 15:48 To: Paul Chatfield Subject: Re: information reduction-database management question Thanks Paul, I appreciate your time and this is an interesting approach. Unfortunately, I need it to work for all types of information, including character data (i.e. text). Again.. thanks

[R] How to say if error

2010-06-24 Thread Paul Chatfield
Hi - I am looping over a structural equation model for a variety of datasets. Occasionally, the model returns an error and the loop then breaks. I'd like to set a condition which says something like if error, then print NAs rather than the loop breaking, but I don't know how to say if error.

Re: [R] How to say if error

2010-06-24 Thread Paul Chatfield
I've had a look at the conditions in base and I can't get the ones to work I've looked at but it is all new to me. For example, I can work the examples for tryCatch, but it won't print a finally message for me when I apply it to my model. Even if I could get this to work, I think it would

Re: [R] How to say if error

2010-06-24 Thread Paul Chatfield
Thanks Roman - you're right it can do more than I thought. We're close now to solving it I feel. Essentially I'm trying to get the code below to work. If the condition is satisfied, it prints 2, but it doesn't save it in z. I want it to save it even though there's an error. Perhaps you can

Re: [R] How to say if error

2010-06-24 Thread Paul Chatfield
That's great. That solves it. I can work on eloquence later :) I just to sort out that model problem: dof-numeric(10) for (i in 1:10){ x-rnorm(i-1);y-rnorm(i-1) cc - try(lm(y~x), silent=T) if(is(cc,try-error)) {dof[i]-NA} else

Re: [R] How to say if error

2010-06-24 Thread Paul Chatfield
On a similar issue, how can you detect a warning in a loop - e.g. the following gives a warning, so I'd like to set up code to recognise that and then carry on in a loop x-rnorm(2);y-c(1,0) ff-glm(y/23~x, family=binomial) so this would be incorporated into a loop that might be

Re: [R] How to say if error

2010-06-24 Thread Paul Chatfield
Thanks again Joris - you've been very helpful J From: Joris FA Meys [via R] [mailto:ml-node+2267176-1824205151-120...@n4.nabble.com] Sent: 24 June 2010 16:40 To: Paul Chatfield Subject: Re: How to say if error You could do that using the options, eg : set.seed(1) x - rnorm(1:10) y

[R] Read in dataset without saving it

2010-06-09 Thread Paul Chatfield
A simple question - I have a small dataset to read in and want to copy and paste part from Excel and paste it into an R script file without creating more files saving it as a .txt/.csv and then reading that in. I want to read in 3 columns e.g. 1 2.5 3.4 1 2.3 3.1 1 2.6 3.9 2 2.9 2.8 2 2.6 2.9 2

[R] NAs are not allowed in subscripted assignments

2010-04-09 Thread Paul Chatfield
I'm trying to assign NAs to values that satisfy certain conditions (more complex than shown below) and it gives the right result, but breaks the loop having done the first one viz: new-c(rep(5,4),6) for (i in 1:6) {new[new[i]5.5][i]-NA} gives the correct result, though an error message appears

Re: [R] NAs are not allowed in subscripted assignments

2010-04-09 Thread Paul Chatfield
Thank you – that’s sorted it. Trying to make things too complicated! J From: Alain Guillet-2 [via R] [mailto:ml-node+1819104-1154170184-120...@n4.nabble.com] Sent: 09 April 2010 10:34 To: Paul Chatfield Subject: Re: NAs are not allowed in subscripted assignments Maybe you can

[R] Paste expression in graph title

2010-01-25 Thread Paul Chatfield
This was my initial attempt at creating a title on a graph of the R squared value: x-rnorm(10) y-rnorm(10) plot(x,y, main=paste(expression(R^2), = ,round(summary(lm(y~ x))$r.squared, digits=3), sep=)) I've read various other posts that say expression needs to be taken outside the paste, but I

Re: [R] Paste expression in graph title

2010-01-25 Thread Paul Chatfield
.nabble.com] Sent: 25 January 2010 12:21 To: Paul Chatfield Subject: Re: [R] Paste expression in graph title Try this: plot(x, y, main = bquote(R^2 == .(round(summary(lm(y ~ x))$r.squared, 3 On Mon, Jan 25, 2010 at 10:06 AM, Paul Chatfield [hidden email] http://n4.nabble.com/user

[R] Patterned shading in ggplot

2009-11-04 Thread Paul Chatfield
Am trying to produce a graph which prints out well in black and white using ggplot2. I have the following example set up nicely, but want to shade the red bars in one pattern and the blue in another so they print out clearly. I tried changing colours to 1 light, 1 dark, but then the overlapping

Re: [R] Plotting 1 covariate, 3 factors

2009-10-08 Thread Paul Chatfield
Cheers guys that's helpful. Doug, you're right, my code for ff should have been for (i in 1:length(y)) {if (f1[i]==after f3[i]==1) ff[i]-1, after else if(f1[i]==after f3[i]==2) ff[i]-2, after else if(f1[i]==before f3[i]==1) ff[i]-1, before else if(f1[i]==before f3[i]==2) ff[i]-2, before}

Re: [R] Plotting 1 covariate, 3 factors

2009-10-08 Thread Paul Chatfield
That's solved it. Superb! All you probably need is to make f2 a factor (e.g., y ~ factor(f2) | f1). Otherwise dotplot() doesn't know which one to treat as categorical. -Deepayan -- View this message in context:

[R] Plotting 1 covariate, 3 factors

2009-10-07 Thread Paul Chatfield
I'm interested in plotting a y with an x factor as the combination of 2 factors and colour with respect to a third, which the code below does with interaction.plot(). However, this is because I redefine the x to be 1 factor. Is there a way of getting it to plot without redefining it, and

Re: [R] Statistician Needed

2009-08-11 Thread Paul Chatfield
Hi Noah - I work for the statistical services centre and could help. Email p.s.chatfi...@rdg.ac.uk, Paul Noah Silverman-3 wrote: Hello, I've come up with some challenges with my process that are a bit too complicated for the mailing list. Is there anyone out there, preferably a

Re: [R] Combine two matricies

2009-07-13 Thread Paul Chatfield
The following code should do it. This assumes matrices a and x are of the same dimension which is why you can index a as below x[is.na(x)==TRUE]-a[is.na(x)==TRUE] -- View this message in context: http://www.nabble.com/Combine-two-matricies-tp24458609p24458797.html Sent from the R help

Re: [R] random sampling or random replacement

2009-06-25 Thread Paul Chatfield
If you want to average 20% missing values then you could try it in 1 step, viz: sample(c(1:2, rep(NA, 2000)),100) Otherwise, 2 steps is preferable. Use code as below: sample(1:2,100)-kk kk[sample(1:100,20)]-NA Paul -- View this message in context:

[R] Snap axes to origin rather than around it

2009-06-12 Thread Paul Chatfield
I'm trying to plot a graph where the axes go through 0,0, rather than around it combined with a box round the graph, so x-0:10;y-0:10 plot(x,y) gives me a box but doesn't go through the point 0,0, but stays at a distance. In trying to circumvent this problem, I wrote plot(x,y) axis(1,

[R] Curved arrows

2009-04-30 Thread Paul Chatfield
I'm trying to draw an arrow with a curved shaft on the graph as a straight one looks messy on a detailed graph. I've looked in arrows but it doesn't seem to give an option. larrows doesn't look much more promising. I had a look in the archive and couldn't find anything. Any thoughts? Thanks