METAL: A Multi-Agent Framework for Chart Generation with Test-Time Scaling

Chart generation aims to generate code to produce charts satisfying the desired visual properties, e.g., texts, layout, color, and type.It has great potential to empower the automatic professional report generation in financial analysis, research presentation, education, and healthcare.In this work, we build a vision-language model (VLM) based multi-agent framework for effective automatic chart generation.Generating high-quality charts requires both strong visual design skills and precise coding capabilities that embed the desired visual properties into code.Such a complex multi-modal reasoning process is difficult for direct prompting of VLMs.To resolve these challenges, we propose METAL (Multi-agEnT frAmework with vision Language models for chart generation), a multi-agent framework that decomposes the task of chart generation into the iterative collaboration among specialized agents.METAL achieves a 5.2% improvement in the F1 score over the current best result in the chart generation task.Additionally, METAL improves chart generation performance by 11.33% over Direct Prompting with LLAMA 3.2-11B.Furthermore, the METAL framework exhibits the phenomenon of test-time scaling: its performance increases monotonically as the logarithm of computational budget grows from 2 9 to 2 13 tokens.