search for: bias

Displaying 20 results from an estimated 1632 matches for "bias".

Did you mean: bas
2017 Jul 09
0
Histogram plots in Lattice with spatialgrid dataframe data
Hello all, After more digging I was able to find out how to do this. The answer came from an example here: https://stackoverflow.com/questions/3541713/how-to-plot-two-histograms-together-in-r yr_1997<-data.frame(bias=ann_bias$bias1997) yr_1998<-data.frame(bias=ann_bias$bias1998) yr_1999<-data.frame(bias=ann_bias$bias1999) yr_2000<-data.frame(bias=ann_bias$bias2000) yr_2001<-data.frame(bias=ann_bias$bias2001) yr_2002<-data.frame(bias=ann_bias$bias2002) yr_2003<-data.frame(bias=ann_bias$bias2003...
2017 Jul 09
2
Histogram plots in Lattice with spatialgrid dataframe data
Hi all, I can not seem to get what I want using the Lattice package to generate an array of histograms of spatialgrid dataframe data. I can use the sp package and spplot to generate an array of maps that display an array of spatialgrid dataframe data -- that's good. I have: spplot(ann_bias,xlim=c(1423987.5,2614612.5),ylim=c(-5862637.5,-4624387.5),at=brks,col.regions=colp(length(brks)-1),main="NOAA/NWS OHRFC Stage-3/MPE Precipitation Estimate Bias with respect to PRISM\n1997 - 2016") Which works... I can also do histogram(ann_bias$bias1997), which works too. I have also cre...
2017 Jul 10
1
Histogram plots in Lattice with spatialgrid dataframe data
...ons below). In the future, follow the recommendations of the Posting Guide: use plain text, and provide a reproducible example. Some elaborations on what "reproducible" means are [1][2][3]. One issue here was that you did not include sample data to work with (I have assumed below that ann_bias has no other columns than the biasNNNN columns, which is not the usual case). There are a number of ways to achieve the reshaping of your ann_bias data frame that are less painful than your approach. For example, the base R "stack" function: bias2 <- stack( ann_bias ) names( bias2 )...
2005 Feb 23
3
bias of a boot statistic
Question: How can I get access to the bias value of a boot statistic? Details: Boot function: boot(data, statistic, R, sim="ordinary", stype="i", strata=rep(1,n), L=NULL, m=0, weights=NULL, ran.gen=function(d, p) d, mle=NULL, ...) When I create an object, containing the bootstrap statistic (objec...
2003 Dec 11
2
read.spss question warning compression bias
Hello again I have a file from SPSS in .sav format. when I run library(foreign) cvar<-as.data.frame(read.spss("c:\\NDRI\\cvar\\data\\cvar2rev3.sav")) I get a warning Warning message: c:\NDRI\cvar\data\cvar2rev3.sav: Compression bias (0) is not the usual value of 100. The data appear to be OK, but I am concerned. (I tried searching the archives and the documenation for data import export, but saw nothing). Thanks as always Peter Peter L. Flom, PhD Assistant Director, Statistics and Data Analysis Core Center for Drug U...
2008 Jun 04
2
array of arrays
Dear R users, I want to calculate the bias and variance of an estimator for several values of two parameters a and b. For example : b1 b2 a1 bias bias variance variance a2 bias bias variance variance Can one do array of arrays ? I have tried and it did not work. Actually I would like to get this array...
2009 Nov 11
1
Clarification on generic functions and methods
I have constructed the following functions and need a little clarification: ### function to fit the model parameters jml.fit <- function(dat, con = 1e-3, bias=FALSE, ...){ do stuff ... } ### default function which calls jml.fit jml.default <- function(dat, con = 1e-3, bias=FALSE, ...){ result <- jml.fit(dat, con = 1e-3, bias) result$call <- match.call() class(result) <- "jml" result } ### Function to make use of formula jml.f...
2006 Jul 10
1
How can I obtain the values of BIAS and STD. ERROR from a bootstrap.
R 2.3.1 Windows XP Question: How can I obtain the values of BIAS and STD. ERROR from a bootstrap. Background: I am running a bootstrap: result2<-boot(1:400,regSEvssample,R=5000) and obtain the following results: Bootstrap Statistics : original bias std. error t1* 1.876602 -0.0001368616 0.1630380 I would like to get the values of ORIGINAL a...
2018 Sep 18
3
Bias in R's random integers?
Dear list, It looks to me that R samples random integers using an intuitive but biased algorithm by going from a random number on [0,1) from the PRNG to a random integer, e.g. https://github.com/wch/r-source/blob/tags/R-3-5-1/src/main/RNG.c#L808 Many other languages use various rejection sampling approaches which provide an unbiased method for sampling, such as in Go, python, and...
2006 Apr 05
1
Combination of Bias and MSE ?
Dear R Users, My question is overall and not necessarily related to R. Suppose we face to a situation in which MSE( Mean Squared Error) shows desired results but Bias shows undesired ones, Or in advers. How can we evaluate the results. And suppose, Both MSE and Bias are important for us. The ecact question is that, whether there is any combined measure of two above metrics. Thank you so much for any reply. Amir Safari ---------------------...
2017 Sep 13
2
Help in R
I don?t know if my question is answerable, but it is worth a try. I have a data set that I am trying to analyze in R for a course and the instructions were to get a standard deviation which I already computed in R and use that number and change it to a biased standard deviation?.(I have the two equations and I understand the difference between the two and how the unbiased has the degree of freedom?..I just do not know how use my standard deviation and transform it in R to a biased one. Thanks in advance, Jessie
2018 Sep 19
2
Bias in R's random integers?
El mi?., 19 sept. 2018 a las 14:43, Duncan Murdoch (<murdoch.duncan at gmail.com>) escribi?: > > On 18/09/2018 5:46 PM, Carl Boettiger wrote: > > Dear list, > > > > It looks to me that R samples random integers using an intuitive but biased > > algorithm by going from a random number on [0,1) from the PRNG to a random > > integer, e.g. > > https://github.com/wch/r-source/blob/tags/R-3-5-1/src/main/RNG.c#L808 > > > > Many other languages use various rejection sampling approaches which > > provide a...
2018 Sep 19
0
Bias in R's random integers?
On 18/09/2018 5:46 PM, Carl Boettiger wrote: > Dear list, > > It looks to me that R samples random integers using an intuitive but biased > algorithm by going from a random number on [0,1) from the PRNG to a random > integer, e.g. > https://github.com/wch/r-source/blob/tags/R-3-5-1/src/main/RNG.c#L808 > > Many other languages use various rejection sampling approaches which > provide an unbiased method for samplin...
2007 May 09
1
Fitting model with response and day bias
Hi, I'm trying to fit a model which has a response bias, but also a day to day bias. If I try to simulate the data, I don't get the right values with optim, and also I can't use the function to give a prediction interval. My simulated data are: DF <- as.data.frame(cbind(x=rep(1:10,2),dag=rep(1:2,each=10))) bias <- c(-0.2,0.5) DF$y <...
2012 Oct 26
1
Gini with bias correction
Hey there, I was wondering if someone could tell me if there's a package or command that allows me to compute a GINI coefficient using a vector of weights. Also the coefficient should be bias corrected. Diego Rojas [[alternative HTML version deleted]]
2018 Sep 19
0
Bias in R's random integers?
...r wrote: > El mi?., 19 sept. 2018 a las 14:43, Duncan Murdoch > (<murdoch.duncan at gmail.com>) escribi?: >> >> On 18/09/2018 5:46 PM, Carl Boettiger wrote: >>> Dear list, >>> >>> It looks to me that R samples random integers using an intuitive but biased >>> algorithm by going from a random number on [0,1) from the PRNG to a random >>> integer, e.g. >>> https://github.com/wch/r-source/blob/tags/R-3-5-1/src/main/RNG.c#L808 >>> >>> Many other languages use various rejection sampling approaches which >...
2003 Jun 13
5
covariate data errors
Greetings, I would like to fit a multiple linear regression model in which the residuals are expected to follow a multivariate normal distribution, using weighted least squares. I know that the data in question have biases that would result in correlated residuals, and I have a means for quantifying those biases as a covariance matrix. I cannot, unfortunately, correct the data for these biases. It seems that this should be a straightforward task, but so much of the literature is concerned with the probability mod...
2018 Sep 19
2
Bias in R's random integers?
...8 a las 14:43, Duncan Murdoch > > (<murdoch.duncan at gmail.com>) escribi?: > >> > >> On 18/09/2018 5:46 PM, Carl Boettiger wrote: > >>> Dear list, > >>> > >>> It looks to me that R samples random integers using an intuitive but > biased > >>> algorithm by going from a random number on [0,1) from the PRNG to a > random > >>> integer, e.g. > >>> https://github.com/wch/r-source/blob/tags/R-3-5-1/src/main/RNG.c#L808 > >>> > >>> Many other languages use various rejection...
2017 Aug 16
1
Bias-corrected percentile confidence intervals
Hi folks, I'm trying to estimate bias-corrected percentile (BCP) confidence intervals on a vector from a simple for loop used for resampling. I am attempting to follow steps in Manly, B. 1998. Randomization, bootstrap and monte carlo methods in biology. 2nd edition., p. 48. PDF of the approach/steps should be available here: https://wy...
2018 Sep 20
1
Bias in R's random integers?
...TML browser interface to help. Type 'q()' to quit R. > set.seed(123) > m <- (2/5)*2^32 > m > 2^31 [1] FALSE > x <- sample(m, 1000000, replace = TRUE) > table(x %% 2) 0 1 499412 500588 So I doubt that this has anything to do with bias from using 32-bit random values. Radford Neal