A series of functions designed to aid in the creation of input files for the 'Circos' visualization platform < http://circos.ca/>. Included are two main function types - make_circos_x() and write_circos_x(). The "make" functions are designed to process an input data set, and return a data frame that can be manipulated and filtered to eliminate the need to write Perl scripts within the 'Circos' software platform for data filtering. The "write" functions take processed data frames from the "make" functions, and write .txt files compatible with the 'Circos' platform. In addition to these function types, there are other accessory functions that aid in the manipulation of the make_circos_x() returned data frames to enhance final visual appeal (such as color_circos_links()).