Displaying 3 results from an estimated 3 matches for "guijarro".
2012 Feb 01
1
package sampling, function strata
Dear all,
I have to select 122 stratified random samples from a population of
>3900 cells. I have 41 strata and I have to draw a different number of
samples from them(between 2 and 8).
I have tried to apply the funtion strata following the instruction in
the manual:
strata(dataframe, stratanames=NULL, size, method=c("srswor"),
pik,description=TRUE)
but I get the error
2011 Sep 28
2
apply lm function to dataset split by two variables
Dear all,
I am not fluent in R and am struggling to 1) apply a lm to a weight-size
dataset, thus the model has to run separately for each species, each
year; 2) extract coefs, r-squared, n, etc. The data look like this:
year sps cm w
2009 50 16 22
2009 50 17 42
2009 50 18 45
2009 51 15 45
2009 51 16 53
2009 51 17 73
2010 50 15 22
2010 50 16 41
2010 50 16 21
2010
2011 Nov 02
0
mapping bathymetries and species abundances
Dear all,
I am new to R and even newer to mapping with R. I have installed
PBSMapping, maptools and maps, and I am struggling to produce a map of
fish abundance in the Grand Banks. I have tried several approaches to
plot the bathymetry in my study area:
1) download the data from http://topex.ucsd.edu/cgi-bin/get_data.cgi
(42N46N313W307W)
To start with, the map I get is blank between