R: Optical Recognition of Handwritten Digits of Frank A,...
optd
R Documentation
Optical Recognition of Handwritten Digits of Frank A, Asuncion A (2010).
Description
The dataset describes n = 1797 digits from 0 to 9 (K = 10), handwritten by 13 subjects.
Raw observations are 32x32 bitmaps, which are divided into nonoverlapping
blocks of 4x4 and the number of on pixels are counted in each block.
This generates p = 64 (= 8x8) variable, recording the normalized counts of pixels in each block and each element
is an integer in the range 0 to 16.
The row names of the matrix optd contains the true labels (between 0 and 9), and the column names of it contains the position of the block in original bitmap.
Usage
data(optd)
showbitmap(index)
Arguments
index
A vector containing integers between 1 and 1797.
Given the observation indices, the showbitmap returns their original 32 by 32 bitmaps on R console.
Details
The original dataset is freely available from USIMachine Learning Repository (Frank and Asuncion (2010)) website http://archive
.ics.uci.edu/ml/datasets.html.
## Not run:
data(optd)
truedigit <- rownames(optd)
(re <- RSKC(optd,ncl=10,alpha=0.1,L1=5.7,nstart=1000))
Sensitivity(re$labels,truedigit)
table(re$labels,truedigit)
## Check the bitmap of the trimmed observations
showbitmap(re$oW)
## Check the features which receive zero weights
names(which(re$weights==0))
## End(Not run)