[R] question about R code

Dear Sir/Madam, If I have matrics as follows: a - c(1,1,0,0) b - c(4,4,0,0) c - c(3,5,5,6) How can I use R code to solve the equation ax^2+bx+c=0. thanks! yuying shi [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing

[R] question about R code

Dear Sir/Madam, If I have matrics as follows: a - c(1,1,0,0) b - c(4,4,0,0) c - c(3,5,5,6) How can I use R code to solve the equation ax^2+bx+c=0. thanks! yuying shi [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing

[R] R help

!= 0) {y.solution[1]- -1*c/b} } else ## Put your R code here } else { ## Put your R code here } y.solution } # Interate through the coefficients y - matrix(0,nrow=4,ncol=4) for (k in 1:4) { y[k,] -SolveQuad(a[k],b[k],c[k]) } y Thanks very much for all the help! yuying shi [[alternative

[R] solve the quadratic equation ax^2+bx+c=0

If I have matrics as follows: a - c(1,1,0,0) b - c(4,4,0,0) c - c(3,5,5,6) How can I use R code to solve the equation ax^2+bx+c=0. thanks! yuying shi [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing list https

[R] some questions

Dear R expert, The following is my questions: 1. How to generate two sequences of 150 uniform deviates, called v1 and v2, in the range [-1,1]. 2. How to compute r=(v1)^2+(v2)^2 3.If r is outside the range of (0,1) then it will be discarded. 4 How to compute (v1)*sqrt(-2*log(r)/r) and output

[R] R questions

help is greatly appreciated. Thanks in advance! best wishes yuying shi [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R

[R] Newton iteration questions

Dear Sir/Madam, If I have a sample of observations that come from an extreme value distribution, the density function for the extreme value distribution is: f(x)=(1/b)exp[-(x-a)/b]exp{-exp[-(x-a)/b]}, b0, x can be any value, my question is how to implement the Newton iteration and

[R] r question

If there are two random variable X1 and X2 which have a bivariate normal distribution with mean vector (10, 10)and variance covariance matrix [21.95 1.953] How to calculate the mean and variance of the function Y=X1/X2? Thanks a lot! xingyu