Egg sizes - egg size measurements

Data of the egg size measurements. iid = individual identity of the mother, mid = row number of the mother in the data file with mothers, are = area of the egg (mm^2), per = perimeter of egg (mm), mxr = semi-major axis (mm), mnr = semi-minor axis (mm).本数据集为鸡蛋尺寸测量数据。其中，变量iid代表产蛋母本的个体标识（individual identity）；mid代表包含母本的数据文件中母本的行号；are代表鸡蛋面积（单位：mm²）；per代表鸡蛋周长（单位：mm）；mxr代表半长轴（单位：mm）；mnr代表半短轴（单位：mm）。