:ֵ

ʽ:abs(a)

˵:aΪ(ʱԾÿԪؽв),ҲΪ(ʱԱֽв)

:

z = [ 1    2.3  0
     -3.6  2   -9 ]

abs(z)//سõ½
ans =
 [ 1    2.3  0
   3.6  2    9 ]