Noun:

1. a matrix with the same number of rows and columns

squaren.正方形；广场；街区；平方；直角尺；<俚>古板的人adj.正方形的；规矩的；结实的；公正的；断然的v.一致；结清；收买；使 ... 成方形；使成平方；调整adv.成直角；直接的；正方形地square key方键

1. Braces are used for the column matrices to distinguish them from rectangular matrices usually put in square brackets.
   大括号用于列矩阵，以便使列矩阵与矩形矩阵区分开，矩形矩阵通常采用方括号。