bytescircle User Manual"

Description

bytescircle is a function that shows statistics about bytes contained in a file as a circle graph of deviations from mean in sigma increments. Histogram and boxplot graphs can also be generated.

The function can be useful for statistically analyze the content of files in a glimpse: text files are shown as a green centered crown, compressed and encrypted files should be shown as equally distributed variations with a very low CV (sigma/mean), and other types of files can be classified between these two categories depending on their text vs binary content, which can be useful to quickly determine how information is stored inside them (databases, multimedia files, etc).

bytescircle() accepts a character string as path for the file, though if it is not indicated, a file selection GUI will demand it. The 'ascii=TRUE' param replicates the linux behaviour of bytes-circle command with params '-o 1' (or equivalently '-b'), as R output does not have colour output. bytescircle's linux command examples can be found here: https://circulosmeos.wordpress.com/2015/10/10/statistics-circle-for-analysing-byte-entropy-in-files/.

bytescircle() outputs data (file, mean, sd, CV, file size) on R console, but this can be turned off using 'output=0'. A value of 2 will output the char array used for ASCII graph output.

'plot' param accepts a number from 0 (no plot) to 5 (boxplot)

Colours can be indicated as a vector of colours from 1 to 3 elements, which will be used differently depending on the plot selected. By default, the first colour of the vector will replace the default green, the second the default red, and the third the default blue. Not all colours are used on every plot.

bytescircle() can accept its own output as input using 'input=variable'. This can be useful for generating a new graph without the hassle of R reading and analysing the file again. The input can also be a bare 256 element vector: in this case each element represents the appeareances in the file of that [n-1] byte value.

bytescircle() parameters

FILE char array with the path to an existing file to analyse. If it is not indicated, a file selection GUI will demand it.

ascii boolean, if TRUE R will output an ASCII circle char of deviations from sigma (true sd). Each ASCII char represents a different deviation from sigma. The array of chars used (from -9/4 to +9/4 sigma, in increments of 0.5 sigma) can be printed using parameter 'output=2'

plot number from 0 to 5, indicates plot to represent:

0: no plot

1: circle of bytes: using an archimedean spiral each byte value is represented with a coloured circle which size indicates the amount of deviation from sigma. A green colour indicates positive sigma value whilst red indicates a negative sigma value. Blue little circles represents byte values that do not appear in the file

2: circle of bytes with indication of the byte bucket represented

3: graph of byte counts: in green values over mean, in red values below it. Also the lines for +/- sd over mean (black dotted line), IQR (Interquartile Range) (dotted green line), and boxplot's binf and bsup values (dotted blue) values are represented as horizontal lines.

  binf=max(min(BYTES$bytes), quantile(BYTES$bytes,0.25)-1.5*IQR(BYTES$bytes))

  bsup=min(max(BYTES$bytes), quantile(BYTES$bytes,0.75)+1.5*IQR(BYTES$bytes))

4: bar graph of byte counts

5: boxplot() graph of byte's data

Note that ascii parameter's value is independent of the value of 'plot'

col vector of color values, colours can be indicated as a vector of colours from 1 to 3 elements, which will be used differently depending on the plot selected. By default, the first colour of the vector will replace the default green, the second the default red, and the third the default blue. Not all colours are used on every plot.

output integer (0, 1, 2), as function outputs data (file, mean, sd, CV, file size) on R console after every call, this output can be turned off using 'output=0'. A value of 2 will output the char array used for ASCII graph output.

input factor or vector, the function can accept its own output as input. This can be useful for generating a new graph without the hassle of R reading and analysing the file again. The input can also be a bare 256 element vector: in this case each element represents the appeareances in the file of that [n-1] byte value.

restrict boolean, if TRUE statistics will use only the number of byte values (buckets) that appear in the file, and not the 256 default value. This makes a difference only if there're byte values that do not appear in the file.

Return value

Returns factor of values :

$bytes: vector of 256 elements, counts of each byte value in the file

$deviation: vector of 256 elements, (count-mean)/sigma for each byte value in the file

$file: char array, input file analysed. If input were a vector or the input factor didn't have a $FILE element, it is "R input"

$mean: mean value

$sd: sigma (true sd) value: sigma=sd()*sqrt((n-1)/n)

$cv: coefficient of variation (mean/sigma*100)

$circle: 14x35 complex matrix representing an ASCII circle. The center of the circle represents the byte with value 0; from it and in counterclockwise next byte values are packaged, so the more the distance from the center, the bigger the value of the represented byte. Elements which do not represent bytes have Imaginary part 1i and Real part 0 (0+1i). Elements which represent bytes have a zero Imaginary part (n+0i). The Real part of each element is the 4*deviation from sigma of the represented byte, calculated as: (BYTES\$bytes - BYTES\$mean)/BYTES\$sd*4
Bytes that do not appear in the file are marked with value 11.0. Deviations over +/-10.0 (no matter how much more) are truncated to exactly 10.0 if over zero, or -10.0 if below zero. Note that this convention allows the use of the truncated values as indexes of a vector of chars to generate the ASCII graph (see ascii=TRUE and last example).

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Examples

BYTES = bytescircle( '/R/.RData', plot=1 )
bytescircle( input=BYTES, plot=2 )
knitr::include_graphics("bytescircle_plot_1.png")
knitr::include_graphics("bytescircle_plot_2.png")

Using an archimedean spiral, each byte value is represented with a coloured circle which size indicates the amount of deviation from sigma. A green colour indicates positive sigma value whilst red indicates a negative sigma value. Blue little circles represents byte values that do not appear in the file.

\newpage

bytescircle( input=BYTES, plot=3 )
knitr::include_graphics("bytescircle_plot_3.png")
bytescircle( input=BYTES, plot=4 )
knitr::include_graphics("bytescircle_plot_4.png")

\newpage

bytescircle( input=BYTES, plot=5 )
knitr::include_graphics("bytescircle_plot_5.png")

Note that an ascii=TRUE parameter would print an ASCII circle on R output (and this is independent of plot parameter value):
```r bytescircle( "bytecircle.Rmd", plot=1, ascii=TRUE )

           ======               
       = ==============         
      [email protected]*#**=====       
     ====*@**=*=****======      
   =====o=****[email protected]**=*@=====    
   [email protected]*=*==O=====****@====    
   [email protected]==*==O======***@====    
   ====****=========***O====    
   =====o=***=====***==*====    
    ====**@**********@=====     
      =====******OO*#=====      
       =================        
          ==========

file =  ./bytescircle.Rmd   
mean =  25.914   
sigma=  103.628 ( CV=  399.8927 \% )   
size =  6.48 kiB  ( 6634 bytes)

This mimics linux bytes-circle command ouput with options set to not show colours (-o 1, or -b) as R console does not allows functions to select their colour output. In this case, each character represents the deviation from mean in 0.5*sigma (true sd) increments, using the array of ten chars: . \, - \~ + * o O # \@ which left-most element represents <= -2.5*sigma, and which rigth-most element represents >= +2.5*sigma ("*" char represents a value between zero and 0.5*sigma). "=" char is used to represent byte values that do not appear in the file (zero count).

\newpage

Notes on implementation

This package is implemented with a fast function in native code for file byte's values reading, that is apt for use with big files, even over 2 or 4 GiB (implements LFS).



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bytescircle documentation built on May 2, 2019, 9:48 a.m.