search for: i_th

Displaying 4 results from an estimated 4 matches for "i_th".

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2007 Oct 26
1
finding birth position
...'s birth history. So, I was thinking of creating six variables boy_1, boy_2, ..., boy_6. boy_1 would record the position of the first boy, boy_2 would record the position of the second boy and so on till boy_6. I want to assign a value of zero to boy_i if the family in question did not have the i_th boy. I am not sure how best to do this (i.e., whether to create variables as I have suggested or do something else) and would appreciate any suggestions. Later, I want to use the information on the position of the male births to compute a likelihood function and do an MLE. Here is how my data fr...
2003 Oct 23
1
Variance-covariance matrix for beta hat and b hat from lme
...for the estimated beta_i hat and b_i hat from the lme fitted object? The reason for needing this is because I want to have interval prediction on the predicted values (at level = 0:1). The "predict.lme" seems to provide point estimates only. The predicted value for new observation of the i_th subject, with E_i and F_i as regressor matrices for fixed- and random-effects respectively, is y_i hat = E_i * beta hat + F_i * b_i hat which can also be written as y_i hat = [ E_i, F_i ] * [ beta hat ', b_i hat' ]' , where prime denotes transpose. Therefore, the variance of y_i hat i...
2005 Apr 27
0
Fitting a kind of Proportional Odds Modell using nlme, polr, lrm or ordgee
...em is how to fit this model in R although I have a SAS code from Whitehead which is availabe at http://www.rdg.ac.uk/mps/mps_home/misc/publications.htm . There it is fit by using Proc NLMIXED. The result for beta is there: The problem is that alpha_{ik} represents the k_th intercept for the i_th study. A "normal" Proportional-Odds model has only alpha_k which represents the k-th intercept without any associaton to the study. I tried to fit it by using the functions of Pinheiro/ Bates nlme, nls, gnls; polr by Venables/Ripley ; lrm by Harrell ordgee by Yan; but I cam...
2009 Jan 07
0
How-To extract data from a matrix of lists subject to a set of given constraints
....mat[[6,4]] $data [1] 1.187133 $variable [1] "10146:6" > d5.mat[[8,4]] NULL > d5.mat[[10,4]] $data [1] 0.7789786 $variable [1] "10146:10" > d5.mat[[50,4]] $data [1] 0.8909976 $variable [1] "10146:50" How can I extract, for instance, all the data from the i_th column of the matrix that satisfy a given conditon? In the case of a matrix A made up of numbers I would write : which (A [,i] > 0.1) ...? Thank you in advance for your help. Maura tutti i telefonini TIM! [[alternative HTML version deleted]]