TY - JOUR T1 - Flowtrace: simple visualization of coherent structures in biological fluid flows JF - bioRxiv DO - 10.1101/086140 SP - 086140 AU - William Gilpin AU - Vivek N. Prakash AU - Manu Prakash Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/11/07/086140.abstract N2 - We present a simple, intuitive algorithm for visualizing time-varying flow fields that can reveal complex flow structures with minimal user intervention. We apply this technique to a variety of biological systems, including the swimming currents of invertebrates and the collective motion of swarms of insects. We compare our results to more experimentally-diffcult and mathematically-sophisticated techniques for identifying patterns in fluid flows, and suggest that our tool represents an essential “middle ground” allowing experimentalists to easily determine whether a system exhibits interesting flow patterns and coherent structures without the need to resort to more intensive techniques. In addition to being informative, the visualizations generated by our tool are often striking and elegant, illustrating coherent structures directly from videos without the need for computational overlays. Our tool is available as fully-documented open-source code available for MATLAB, Python, or ImageJ at www.flowtrace.org. ER -