On Thu, 24 Feb 2022 13:31:09 -0500 Paul Bernal <paulberna...@gmail.com> wrote:
> Basically, what I am being asked to do is to take the > train.csv dataset, and store it in a data structure so that the data > can be reshaped into a matrix of size 28 x 28, then I just need to > print some indices of that (e.g. index 1, 2, 4, 7,, etc.) Is this homework? It's considered a good idea to contact your instructor with homework questions. > dataframe_train <- array(read.csv(file_path_2, header=TRUE, > stringsAsFactors = FALSE), 28, 28) Almost there. Two problems left: 1. You did not remove the first column. R will do what is asked of it and mix the labels with the pixel values. You will probably need to subset the data frame that read.csv() returns to remove it before reshaping the rest of it into a three-way array. 3. The dimensions of the array should be specified in a single 3-element vector: c(N, 28, 28). I don't think there's a convenient way to do that in a single expression. Once you have your pixels in an N by 784 matrix, use c(nrow(your.matrix), 28, 28) to construct the dimension vector. > then printing out several indices by doing (I know this could be done > with a for loop better but I tried this): > print(dataframe_train[1]) That chooses the N'th pixel value from the whole array. The syntax to extract whole slices of an array is different: https://cran.r-project.org/doc/manuals/r-release/R-intro.html#Array-indexing -- Best regards, Ivan ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
