Wolfram Function Repository
Instantuse addon functions for the Wolfram Language
Function Repository Resource:
Produce a Frequency Chaos Game Representation image from a string of nucleotides
ResourceFunction["FCGRImage"][str] gives the Frequency Chaos Game Representation image of a DNA nucleotide sequence str comprised of the characters “A”, “T”, “G” and “C”. 

ResourceFunction["FCGRImage"][str,k] gives the FCGR image at resolution 2^{k}. 

ResourceFunction["FCGRImage"][str,k, bases] gives the FCGR image using a square with corners given by bases, beginning at the lower right and proceeding counterclockwise. 
Select a human gene from the Wolfram Language curated data:
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Show the Chaos Game Representation image for this gene:
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Show this gene at higher levels of pixelation:
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One may observe a fractal nature to these, with similarities appearing as the resolution level is increased:
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Compute the image with respect to a square having the purines positioned at the bottom vertices and the pyrimidines at the top:
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Reverse the order of the purines from the default ordering:
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Wolfram Language 11.3 (March 2018) or above
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