On Fri, Oct 8, 2010 at 12:47 PM, Gabor Grothendieck <ggrothendi...@gmail.com> wrote: > On Fri, Oct 8, 2010 at 11:35 AM, epowell <epowe...@med.miami.edu> wrote: >> >> My data looks like this: >> >>> data >> name G_hat_0_0 G_hat_1_0 G_hat_2_0 G_0 G_hat_0_1 G_hat_1_1 G_hat_2_1 G_1 >> 1 rs0 0.488000 0.448625 0.063375 1 0.480875 0.454500 0.064625 1 >> 2 rs1 0.002375 0.955375 0.042250 1 0.000000 0.062875 0.937125 2 >> 3 rs2 0.050375 0.835875 0.113750 1 0.877250 0.115875 0.006875 0 >> 4 rs3 0.000000 0.074750 0.925250 2 0.897750 0.102000 0.000250 0 >> 5 rs4 0.000125 0.052375 0.947500 2 0.261500 0.724125 0.014375 1 >> 6 rs5 0.003750 0.092125 0.904125 2 0.023000 0.738125 0.238875 1 >> >> And my task is: >> For each individual (X) on each row, to find the index corresponding to the >> max of G_hat_X_0, G_hat_X_1, G_hat_X_2 and then increment the cell of the >> confusion matrix with the row corresponding to that index and the column >> corresponding to G_X. >> >> For example, in the first row and the first individual, the index with the >> max value (0.488000) is 0 and the G_0 value is 1, so I would increment >> matrix index of the first row and second column. (Note that the ranges >> between rows and columns are one off. That is accounted for in the code.) >> >> In reality the data will be much bigger, containing 10000 rows and a >> variable number of columns (inds) between 10 and 500. >> >> The correct result is: >> >>> cmat >> tru_rr tru_rv tru_vv >> call_rr 2 2 0 >> call_rv 0 4 0 >> call_vv 0 0 4 >> > > If we reform data into a 3d array, arr, it can be vectorized like this > where the two args of table correspond to Gmax and Gtru: > > arr <- array(t(data[-1]), c(4, 2, 6)) > table(apply(arr[-4,,], 2:3, which.max), arr[4,,] + 1)
A couple of further improvements are that we can replace the array, arr, with a matrix, mat, and also we can add dimension names in the table() call: mat <- matrix(t(data[-1]), 4) table(Gmax = apply(mat[-4,], 2, which.max), Gtru = mat[4,] + 1) -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
