The paper proposes a new method to study transverse flow effects in relativistic nuclear collisions by analyzing the azimuthal distribution of particles using Fourier analysis. The authors suggest that this approach naturally incorporates both directivity and two-dimensional sphericity methods, providing a clear physical interpretation of the flow analysis. The method involves dividing the rapidity range into narrow windows and performing Fourier analysis on the azimuthal distributions within each window. The Fourier coefficients of different harmonics reflect different types of anisotropy, such as directed flow and squeeze-out flow. The paper discusses the impact of finite particle fluctuations and particle correlations, and proposes methods to handle these issues. It also explores the correlations between flow angles in different rapidity windows and different particle types, which can provide insights into the overall flow picture. The authors show that their method is consistent with existing methods like directivity and sphericity analysis, but offers additional information for understanding three-dimensional event shapes.The paper proposes a new method to study transverse flow effects in relativistic nuclear collisions by analyzing the azimuthal distribution of particles using Fourier analysis. The authors suggest that this approach naturally incorporates both directivity and two-dimensional sphericity methods, providing a clear physical interpretation of the flow analysis. The method involves dividing the rapidity range into narrow windows and performing Fourier analysis on the azimuthal distributions within each window. The Fourier coefficients of different harmonics reflect different types of anisotropy, such as directed flow and squeeze-out flow. The paper discusses the impact of finite particle fluctuations and particle correlations, and proposes methods to handle these issues. It also explores the correlations between flow angles in different rapidity windows and different particle types, which can provide insights into the overall flow picture. The authors show that their method is consistent with existing methods like directivity and sphericity analysis, but offers additional information for understanding three-dimensional event shapes.