用java实现浮点数加减乘除四则混合运算，矩阵加法，减法，与数乘，与数除，两个矩阵相乘，转置，逆阵，产生单位阵，操作数与变量的转换，操作数取反，栈的一些基本操作。-achieve float with the arithmetic four mixed computing, matrix addition, subtraction, multiplication, with the exception of a few, two matrix multiplication, to home, a