Why do languages require parenthesis around expressions when used with "if" and "while"? The ecdf function in R generates the empirical cumulative distribution function for a set of observations. I tried the following code and it returns NAs data$Date <- as.Date(data$Date, "%B %d, %y %I:%M:%S %p") Any help would be highly appreciated Reply With Quote + Reply to Thread Recall that R also provides a simulation-based method as an alternative to this parametric test. Check This Out

The data was imported into R from a csv file. Formally where n is the total number of data values. We **will see this below.** It turns out that there is a relationship between the temporal and spatial correlation in these data. http://stackoverflow.com/questions/25184569/error-when-trying-to-coerce-date-format-in-r

Two of its parameter arguments are the desired mean and standard deviation of the log-transformed variable. List components are accessed using double bracket notation. > the.lags[[1]] [1] 2 1 2 1 1 1 2 1 37 2 1 Just center intervals of length one over each of the possible discrete values. I tried your commandson Windows 2000 Pro and Windows XP Pro and was unable to reproducethe output R gave you on either:as.POSIXlt("1970-01-01")[1] "1970-01-01"as.POSIXlt("1970-01-02")[1] "1970-01-02"as.POSIXlt("1970-02-01")[1] "1970-02-01"as.POSIXlt("1970-12-31")[1] "1970-12-31"as.POSIXlt( strptime("1970-01-01",format="%Y-%m-%d") )[1] "1970-01-01"is.na( strptime("1970-01-01", f

An approximate 95% confidence interval is given by where N is the number of pairs of observations that went into the calculation. http://www.R-project.org/posting-guide.html Received on Tue Oct 12 02:44:34 2004 This message: [ Message body ] Next message: Tony Plate: "Re: [R] read "4-jan-02" as date" Previous message: wfang: "[R] How to read get.acf<-function(maxlag,oldei,lag.list) { #center the variable ei<-oldei-mean(oldei) #initialize variables N.list<-length(ei) ACF.list<-1 total.sum<-0 total.count<-0 #cycle through all desired lags for (i in 1:maxlag) { all.guys<-NULL full.list<-NULL #cycle through lag.list looking for the desired If we treat the sample times as fixed then we would expect in a truly randomized design that the sample times would occur randomly with respect to reef locations.

The converted data looks like the following "2006-04-29" "2006-04-30" NA NA NA Thanks again Reply With Quote 03-11-201206:28 PM #7 Lazar View Profile View Forum Posts Phineas Packard Location Sydney Posts Anderson-Darling test The Anderson-Darling test, like the Kolmogorov-Smirnov test, compares the empirical and theoretical cumulative distribution functions. See lecture 6. https://stat.ethz.ch/pipermail/r-help/2004-February/045941.html D.

In general, dealing with data that exhibit both spatial and temporal correlations is not trivial. ndates1 <- as.Date(dates1, "%d%B%Y"); ndates1 [1] "2001-09-06" "2004-06-21" "2006-07-04" "2005-08-06" class(ndates1) [1] "Date" Case 3: Formatting a vector with inconsistent date formats If you can see that there are multiple date How to cite this page Report an error on this page or leave a comment The content of this web site should not be construed as an endorsement of any particular Forum Normal Table StatsBlogs How To Post LaTex TS Papers FAQ Forum Actions Mark Forums Read Quick Links View Forum Leaders Experience What's New?

In R the lognormal cumulative distribution function is plnorm. http://grokbase.com/t/r/r-help/094wz4jpjw/working-with-date-values Join Today! + Reply to Thread Results 1 to 15 of 15 Thread: Convert factor to date Thread Tools Show Printable Version Email this Page… Subscribe to this Thread… Display Linear This highlights what I like to call the "goldilocks problem" in statistics. In this version of the test the values of the parameters of the theoretical distribution must be known exactly and not estimated from the data.

I thought it would be > very simple, but after checking the documentation and the > list I still don't have something that works. > > 1. Gabor Grothendieck Threaded Open this post in threaded view ♦ ♦ | Report Content as Inappropriate ♦ ♦ Re: help working with date values In reply to this post by R packages used date for the function as.date MASS for the function glm.nb truncgof for the function ad.test Testing Goodness of Fit to Continuous Distributions Pearson test In lecture 4 (lab Use a format appropriate to the misread dates.

For the coral data we've seen that statistical dependence manifests itself as temporal correlation. Second, you need to convert your date factors into characters on conversion; otherwise, there can be problems when converting because dates can be referenced as numeric objects (number of days since Although the primary use of the Pearson chi-squared test is in assessing the fit of discrete distributions to data, it can also be used to test the fit of continuous probability this contact form Recall that a random variable is said to have a lognormal distribution if the natural logarithm of that random variable has a normal distribution.

Unlike the Kolmogorov-Smirnov test, the Anderson-Darling test is valid even when the parameters of the theoretical model are estimated using the data. Why is looping over find's output bad practice? In addition there is an optional sims argument for specifying the number of simulations desired for computing the p-value. > library(truncgof) > ad.test(amy5$fg.pop,'plnorm', list(meanlog=mean(log(amy5$fg.pop)), sdlog=sd(log(amy5$fg.pop))), sim=1000) Supremum Class Anderson-Darling Test data:

Although there is no complete remedy for the deficiencies inherent in observational data, it is possible to control for some of the problems statistically. Accordingly its confidence interval **is so wide that we would** fail to call it significantly different from zero. How would you model 'a sphere with a shell' like object? The R equivalent of the above expression applied to a lognormal distribution is shown below. > exp.probs<-c(plognorm.func(.5), sapply(seq(1.5,60.5,1), function(x) plognorm.func(x)-plognorm.func(x-1)), 1-plognorm.func(60.5)) #error check: verify that the probabilities sum to 1 >

as.Date returns the error below. Based on a single test we can never be sure if the model truly fits the data or if it appears to fit only because of the way we grouped things. D. > Spatial Statistical Analyst > Everglades and Dry Tortugas National Park > 950 N Krome Ave (3rd Floor) > Homestead, Florida 33034 > > [hidden email] > Office (305) 224 In our vector dates2, we can start by specifying a date format that appears appropriate for the first few dates including %d, which allows for days within a month to optionally

sector.plot<-function(num,mycol) { #plot all the reefs plot(subset.corals$Lat,subset.corals$Lon, pch=1, cex=.5, col='grey70', xlab='Latitude', ylab='Longitude') #connect current sampled reefs with line segments line.plot(sector.breaks[num], sector.breaks[num+1]-1, mycol, 1, 3) #connect last of current reefs to next To focus on the first year, I pull off the observations corresponding to these dates and display the identity of the geographic sectors of the reefs in the order the samples I call the function get.acf and its code is displayed below.

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