Figure 2 - T1 transitions (cell intercalations)

Raw angles of T1 events and processed statistics of these events. We define a T1 event as any cell-cell junction in which two neighboring cells lose their junction/connection in the endoderm or two non-neighboring cells gain a junction. <br> confirmed_t1_angles.mat contains a struct with fields: t1timepoints_merge: timepoints for each event in which two cells gain a junction, in minutes. t=123 corresponds to the onset of the first constriction. t1timepoints_split : timepoints for each event in which two cells lose a junction, in minutes. t=123 corresponds to the onset of the first constriction. theta_merge : angle of the curve connecting the merging cells in the tissue frame of reference, with respect to the longitudinal axis. theta_split : angle of the curve connecting the cells that are losing connection, measured in the tissue frame of reference, with respect to the longitudinal axis. <br>

T1事件（T1 event）的原始角度数据与对应事件的处理统计量。我们将T1事件定义为：在内胚层中，任意一对相邻细胞最终丧失其连接界面，或是任意一对非相邻细胞获得连接界面的细胞-细胞连接。<br>confirmed_t1_angles.mat 包含一个结构体，其字段说明如下：
t1timepoints_merge：各细胞连接形成事件的时间点（单位：分钟），其中t=123代表首次收缩的起始时刻。
t1timepoints_split：各细胞连接丧失事件的时间点（单位：分钟），其中t=123代表首次收缩的起始时刻。
theta_merge：在组织坐标系下，连接正在融合的细胞的曲线相对于纵轴的角度。
theta_split：在组织坐标系下，连接即将丧失连接的细胞的曲线相对于纵轴的角度。