[R] Pixel Image Reshaping using R

[Paul Bernal]

Dear friends,

I apologize if the description is  a bit long, but I think that I need to
be as specific as possible so that you guys can help.

I wil share with you a file (train.csv), which contains gray-scale images
of hand-drawn digits, from zero through 9.

Each image is 28 pixels in height and 28 pixels in width, for a total of
784 pixels in total. Each pixel has a single pixel-value associated with
it, indicating the lightness or darkness of that pixel, with higher numbers
meaning darker. This pixel-value is an integer between 0 and 255,
inclusive. The training data set, (train.csv), has 785 columns. The first
column, called ”label”, is the digit that was drawn by the user. The rest
of the columns contain the pixel-values of the associated image. Each pixel
column in the training set has a name like pixel x, where x is an integer
between 0 and 783, inclusive. To locate this pixel on the image, suppose
that we have decomposed x as x = i ∗ 28 + j, where i and j are integers
between 0 and 27, inclusive. Then pixel x is located on row i and column j
of a 28 x 28 matrix, (indexing by zero). or example, pixel 31 indicates the
pixel that is in the fourth column from the left, and the second row from
the top, as in the ascii-diagram below.

  This data is set up in a csv file which will require the reshaping of the
data to be 28 × 28 matrix representing images. There are 42000 images in
the train.csv file. For this problem it is only necessary to process
approximately 100 images, 10 each of the numbers from 0 through 9. The goal
is to learn how to generate features from images using transforms and first
order statistics.

So I need to develop an algorithm to store the data in a data structure
such that the data is reshaped into a matrix of size 28 x 28 and then I
have to plot the developed matrix for indices 1, 2, 4, 7, 8, 9, 11. 12, 17
and 22.

I have been looking for information about how to process this with R, but
have not found anything yet.

The dataset is attached in this e-mail for your reference.

Any help and/or guidance will be greatly appreciated.

Best regards,
Paul
 train.csv
<https://drive.google.com/file/d/1WPb7bKHJ8BlzuLKJogMOAOqb-VCoXDMp/view?usp=drive_web>

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