search for: biostatisics

Displaying 14 results from an estimated 14 matches for "biostatisics".

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2009 Aug 11
1
re placePatterns() for multiple words replacement in tm
Hi all, I wonder how you can replace all words that need to be changed using replacePatterns(). The following is my code. I want to replace both "abc" and "def" to " Yes ". However, I can only replace the first occurrence in sample[[1]]. > sample[[1]] [1] abc def ghi > change <- c("abc","def") >
2009 Aug 26
1
specify a model in differential equations (nlme)
Dear all, I wonder if there is a way to specify a model in differential equations for nlme(). Or in other packages? Appreciate any comment. Thanks. Jun Shen [[alternative HTML version deleted]]
2009 Aug 18
2
value of nth percentile
Dear All, I have to get the value of say 90th percentile of precipitation time series.. The series is of daily precipitation value of 96 years, I have to to get 90the percentile value of daily precipitation each year. If you know the R code or command for this please let me know. I would appreciate your early response. Thanking you, Sincerely, Ajay.
2009 Aug 12
2
R numeric string problem
Hi, I have a text (.dat) file, in which each row contains several long numeric strings. One of the strings is 38 digits long, for example: 03200801200801172008011720092904008901 When I read in the data file, this string shows up as 3.200801e+36. To get rid of the scientific notation, I used "options(scipen=999)." When I did this, the scientific notation went away, but the numeric
2009 Aug 19
3
a naive question
Hi, and my apologies for the following very naive question : I would like to read a column of numbers in R and plot a histogram. eg : x<-read.table("txSTART"); y<-as.numeric(x); and I do obtain the error : Error: (list) object cannot be coerced to type 'double'. Please could you let me know the way to fix it. thanks, bogdan <r-help@r-project.org> [[alternative
2009 Aug 27
2
setting par(srt) according to plot aspect ratio
How can I look up the aspect ratio of a plot, so I can use that to correctly adjust the angle of text which is supposed to be parallel to a line in the plot? The following example code works for a 1:1 aspect ratio, but puts the text at the wrong angle if the plot region is short and wide or tall and narrow. I can't find a par() component containing the plot aspect ratio. It will be for
2009 Aug 21
5
splitting a string up
x <- "1041281__2009_08_20_.lev" I would like to split this string up and only extract the leading numbers. 1041281 to use as a label for a data column in a bigger for loop function to read in data. regards, -- Stephen Sefick Let's not spend our time and resources thinking about things that are so little or so large that all they really do for us is puff us up and make us
2009 Aug 11
3
Is there a summary on different version of 'apply' functions? What is the meaning of the prefixes?
Hi, There are quiet a few different 'apply' functions, such as lapply, sapply and many more. I'm very familiar with the 'Apply' function in Mathematica. Can somebody point me a summary of all the 'apply' functions in R. Also, I'm curious that what 'l' and 's' (and other prefixes) stand for in 'lapply' and 'sapply' Regards, Peng
2009 Aug 25
3
Regular expression to define contents between parentheses
Hello dear R-helpers, I haven't been able to figure out of find a solution in the R-help archives about how to delete all the characters contained in groups of parenthesis. I have a vector that looks more or less like this: myvector<-c("something (80 km/h, sd) & more (6 kg/L,sd)", "somethingelse (48 m/s, sd) & moretoo (50g/L , sd)") I want to extract all
2009 Aug 24
1
lme, lmer, gls, and spatial autocorrelation
Hello folks, I have some data where spatial autocorrelation seems to be a serious problem, and I'm unclear on how to deal with it in R. I've tried to do my homework - read through 'The R Book,' use the online help in R, search the internet, etc. - and I still have some unanswered questions. I'd greatly appreciate any help you could offer. The super-super short explanation is
2009 Aug 13
3
shading between two smoothed curves
I have a set of 52 weekly values, one is the desired high lake stage for a week, and the other is the desired low lake stage for each week. It looks like this: week High Low 1 16 14.5 2 16 14.5 3 15.95 14.45 4 15.84 14.34 5 15.73 14.23 6 15.61 14.11 7 15.5 14 8 15.38 13.88 9 15.25 13.75 10 15.13 13.63 .... 52 15 13.5 I can plot out two nice curves
2009 Aug 25
3
Covariates in NLS (Multiple nonlinear regression)
Dear R-users, I am trying to create a model using the NLS function, such that: Y = f(X) + q + e Where f is a nonlinear (Weibull: a*(1-exp(-b*X^c)) function of X and q is a covariate (continous variable) and e is an error term. I know that you can create multiple nonlinear regressions where x is polynomial for example, but is it possible to do this kind of thing when x is a function with unknown
2009 Aug 27
5
Transform data for repeated measures
I have a dataset that I'm trying to rearrange for a repeated measures analysis: It looks like: patient basefev1 fev11h fev12h fev13h fev14h fev15h fev16h fev17h fev18h drug 201 2.46 2.68 2.76 2.50 2.30 2.14 2.40 2.33 2.20 a 202 3.50 3.95 3.65 2.93 2.53 3.04 3.37 3.14 2.62 a 203 1.96 2.28 2.34 2.29 2.43 2.06 2.18 2.28 2.29 a
2009 Aug 19
4
Several simple but hard tasks to do with R
Hello everybody. I've been learning R for about a month to do a econometric study and now i'm stuck with some problems to make R do the things I want. Here I give the list of things I wanna do from the most simple to the more complex (for me of course): 1. Make a log. I've been using Stata and there i have a great tool to register what the program do: the log file, wich it's a