Transpose vector extracted from a matrix Hello,
I am doing a recursive analysis that uses every line (vector) of a matrix in a loop. In the model, I need to transpose those vectors that are extracted from a matrix. Using simple vectors (no matrix involved) the transpose function works fine: simplevector <-matrix(1:3,3,1) tsimplevector <-t(simplevector) #transposed dim(simplevector) #3x1 matrix (vector) dim(tsimplevector)#1x3 PROBLEM: However, when the vector is extracted from a matrix, its dimension is NULL. In this case the transposed dimension is correct, but you'll see the next example, that if a row was extracted, the dimension would be wrong: initialmatrix <- matrix(1:9,3,3) extractedvector <-initialmatrix[,1] # extract first columm as vector textractedvector <-t(extractedvector)#transposed dim(extractedvector) #NULL!!!! <- not working dim(textractedvector)#1x3 as expected I have tried to transform the extracted vector as.vector and as.matrix. as.vector does not give the what I want (still NULL) and as.matrix can't specify the number of row and columns so both vectors are vertical. In this example, I extract a column and a row. Notice that both as.matrix(vector) have the same dimension. Notice that both transposed vectors have 1x3 dimensions. initialmatrix <- matrix(1:9,3,3) extractedvector3x1 <-initialmatrix[,1] # extract first columm as vector extractedvector1x3 <-initialmatrix[1,] # extract first row as vector #Both are NULL dim(extractedvector3x1) #NULL!!!! dim(extractedvector1x3) #NULL!!!! #transposed dimensions both 1x3 dim(t(extractedvector3x1)) #1x3 dim(t(extractedvector1x3)) #1x3 <- not 3x1 #as.vector: still NULL dim(as.vector(extractedvector3x1)) #NULL!!!! dim(as.vector(extractedvector1x3)) #NULL!!!! #as.matrix: Both dim at 3x1 dim(as.matrix(extractedvector3x1)) #3x1 dim(as.matrix(extractedvector1x3)) #3x1 <- Problem: not 1x3 #as.matrix transposed: Both dim at 1x3 dim(as.matrix(t(extractedvector3x1))) #1x3 dim(as.matrix(t(extractedvector1x3))) #1x3 <- Problem: not 3x1 How can I get correct dimensions? Is there a way to specify dimensions in as.matrix? Neuro ______________________________________________ [email protected] 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.
