TreeMerge: A Visual Comparative Analysis Method for Food Classification Tree in Pesticide Residue Maximum Limit Standards

Food classification is an important part of food safety standards. In this paper, we propose a novel visual comparative analysis method for trees (FCTs) in pesticide maximum residue limit (MRL) standards, called TreeMerge, to lay the foundation comprehensive comparison MRL First, union tree constructed by combining two FCTs be compared. Then, sunburst with embedded chordal graph (SECG) and overlapping circular treemap (OCT), which are new visualization solutions designed used show similarities differences tree. SECG can express hierarchical structure similarity between corresponding nodes at same time. OCT uses improved nested Venn diagram (overlapping circle) attribute values each layer circle-filling layout algorithm based on testing circle improve readability space utilization view. Finally, system comparing FCT, named FCTvis, implemented support exploration structural difference pattern standards quantity or scale limits various foods. The effectiveness TreeMerge was verified case studies Chinese Mainland Hong Kong.