sample

I have a matrix in R that I would like to take a single random sample from each row. Some of my data is in NA, but when taking the random sample I do not want the NA to be an option for the sampling. How would I accomplish this? For example, a <- matrix (c(rep(5, 10), rep(10, 10), rep(NA, 5)), ncol=5, nrow=5) a [,1] [,2] [,3] [,4] [,5] [1,] 5 5 10 10 NA [2,] 5 5 10 10 NA [3,] 5 5 10 10 NA [4,] 5 5 10 10 NA [5,] 5 5 10 10 NA When I apply the sample function to this matrix to output another matrix I get b <- matrix(apply(a, 1, sample, size=1), ncol=1) b [,1] [1,] NA [2,] NA [3,] 10 [4,] 10 [5,]

So I am trying to see how close the sample size calculations (for two sample independent proportions with unequal samples sizes) are between proc power in SAS and some sample size functions in r. I am using the data found here at a UCLA website. The UCLA site gives parameters as follows: p1=.3,p2=.15,power=.8,null difference=0, and for the two-sided tests it assumes equal sample sizes; for the unequal sample size tests the parameters are the same, with group weights of 1 for group1 and 2 for group2, and the tests they perform are one-sided. I am using the r function pwr.t.test(n=NULL,d=0,sig

Basically I am teaching myself C++ and part of the program function will be to open and close an image specified. How would I go about doing this? Or what resource would I use? Thanks! deeiip In c++ (without any extra library) you may open an image. But there will be nothing particularly useful except a bunch of binary data. then you have to use your own decoder If you use opencv you can write to open an image and display it: Mat m("fileName"); imshow("windowName",m); To do the same with a general purpose library like qt you can use this code : int main(int argc, char *argv[]) { QApplication a

This question already has answers here : generate random integers between two values with a given probability using R (2 answers) Closed 6 years ago . I need to get out a sample of subjects from a list to assign them as a Control Group for a study which has to have a similar composition of variables. I am trying to do this in R with the sample function but I don´t know how to specify the differetnt probabilities for each variable. Lets say I have a table with the following headers: ID Name Campaign Gender I need a sample of 10 subjects with the following composition of Campaign attributes: D2D

So following up from here , I now need to collect negative samples, for cascaded classification using OpenCV. With positive samples, I know that all samples should have the same aspect ratio. What about negative samples? Should they all be larger than positive samples (since OpenCV is going to paste positives on top of negatives to create the test images). Should all be the same size? Can they be arbitrary sizes? Should they too have the same aspect ratio among themselves? From OpenCV doc on Cascade Classifier Training : Negative samples are taken from arbitrary images. These images must not

I have a JavaScript app with a requirement to protect the drawing interface of the model so that it is not to public. I want to use three.js on a server, save the model in JSON format and deliver it the client side. Three.js on the client will display it. But I don't know how to implement it on a server. Are there any Node.js examples that run three.js apps? If so, how do I save a mesh into JSON format from three.js? But I don't know how to implement it on a server. three module Are there any Node.js examples that run three.js apps? Yes If so, how do I save a mesh into JSON format from three