search for: paleontological

Hello Everyone, I would like to know if I can call one of the columns of a list, to use it as a variable in a function. Thanks in advance for any advice! Jana -- Jana Makedonska, B.Sc. Biology, Universite Paul Sabatier Toulouse III M.Sc. Paleontology, Paleobiology and Phylogeny, Universite de Montpellier II Ph.D. candidate in Physical Anthropology and Part-time lecturer Department of

Dear all, Several days ago, I posted How to write a bmp file pixel by pixel. Instead of bmp, I succeeded in writing a PPM file by using the pixmap package. Thanks for the hint generously provided by Uwe Ligges. Now I have a new question. How to convert a PPM file to BMP file in R? I know I can do this in photoshop or by some other softwares, but I think if I Can do this in R, that

Dear all, I open a bmp device by the bmp() function in the png package, but I don't know how to write color pixel by pixel into the file? Any help or hint? What I want to do is to create a 512*512 bmp file with certain dots being red and others black. I have all the pixel coordinates for the red dots, but I don't know how to draw the color on the device. Please help

Hi Everyone, I am working with the R function "dataEllipse". I plot the 95% confidence ellipses for several different samples in the same plot and I color-code the ellipse of each sample, but I do not know how to specify a different line pattern for each ellipse. I can only modify the pattern for all ellipses with the "lty" argument. Any help will be highly appreciated.

I've been using the package rpart with R 1.3.0 for Windows to produce simple classification trees for some measurement data from paleontological specimens. Both the rpart documentation and the output confirm that the program produces splits on continuous data that leave "holes" in the data. It is probably of little practical importance, but is there a reason why the binary splits are constructed in the form (e.g): x7 < 3...

...n.r-project.org/web/packages/stratigraph/index.html It includes tools for plotting pollen diagrams, an implementation of an evolutionary algorithm for drawing stratigraphic lines of correlation, and several other functions for the analysis and plotting of geological, biological, ecological, and paleontological data distributed through time or stratigraphic depth. There are still some problems with the windows binary, which will be resolved shortly, but a source install should work. Older versions, which have been privately circulated in the past year are available at http://www.bricol.net/stratigrap...

...n.r-project.org/web/packages/stratigraph/index.html It includes tools for plotting pollen diagrams, an implementation of an evolutionary algorithm for drawing stratigraphic lines of correlation, and several other functions for the analysis and plotting of geological, biological, ecological, and paleontological data distributed through time or stratigraphic depth. There are still some problems with the windows binary, which will be resolved shortly, but a source install should work. Older versions, which have been privately circulated in the past year are available at http://www.bricol.net/stratigrap...

Here's a question for ecologists on the r-help list-- I'm addressing this to ecologists in particular because they're most likely to be familiar with the equation in question but I'll be happy to discuss the problem with anyone who's willing to take a whack at it. I'm trying to write a function to calculate the large sample variance of species richness estimates by

Curses, my laptop is hallucinating again. Hope I can get through this. So we're talking about correlations between binary variables. Suppose we have two 0-1-valued variables, x and y. Let A <- sum(x*y) # number of cases where x and y are both 1. Let B <- sum(x)-A # number of cases where x is 1 and y is 0 Let C <- sum(y)-A # number of cases where y is 1 and x is 0 Let D <- sum(!x

Hi Richard, Nice to know you had similar experience. Yes, your understanding is right. all correlations are negative after removing double-zero rows. It is consistent with a heatmap we generated. 1 is for a cancer patient with a specific mutation. 0 is no mutation for the same mutation type in a patient. a pair of mutation type (two different mutations) are exclusive for most of patients in

Your expanded explanation helps clarify your intent. Herewith some comments. Of course, feel free to ignore and not respond. And, as always, my apologies if I have failed to comprehend your intent. 1. I would avoid any notion of "statistical significance" like the plague. This is a purely exploratory exercise. 2. My understanding is that you want to know the proportion of rows in a

HI Bert, Thank you for extra help!! Yes, exactly, your interpretation is perfectly correct and your R code is what I should look for. after generated all those negative values of correlation, I thought about the extremely small p values associated with those negative correlation, which is not meaningful as I truncated my data. When examining the exclusiveness of mutation pairs, what I first

Let's go back to the original posting. > > > >> in each column, less than 10% values are 1, most of them are 0; > > > > > > > >> so I want to remove a row with value of zero in both columns when calculate correlation between two columns. > > So we're talking about correlations between binary variables. Suppose we have two 0-1-valued

...ratum for small units. The well known cumulative root frequency rule of Dalenius and Hodges and the geometric rule of Gunning and Horgan are also implemented. * stratigraph (0.61) Walton A. Green http://crantastic.org/packages/stratigraph A collection of tools for plotting and analyzing paleontological and geological data distributed through through time in stratigraphic cores or sections. Includes some miscellaneous functions for handling other kinds of palaeontological and paleoecological data. * survPresmooth (1.0) Ignacio Lopez-de-Ullibarri http://crantastic.org/packages/survPresmo...