内容简介作者简介 - 科学与工程计算系

【例 2.12.1-2】非数元素的寻访
rand('state',0)
R=rand(2,5);R(1,5)=NaN;R(2,3)=NaN
R =
0.9501 0.6068 0.8913 0.4565 NaN
0.2311 0.4860 NaN 0.0185 0.4447
isnan(R)
ans =
0 0 0 0 1
0 0 1 0 0
Linear_index=find(isnan(R))
[r_index,c_index]=ind2sub(size(R),Linear_index);
disp('r_index c_index'),disp([r_index c_index])
Linear_index =
6
9
r_index c_index
2 3
1 5
2.12.2 “空”数组
【例 2.12.2-1】关于“空”数组的算例。
(1)
a=[],b=ones(2,0),c=zeros(2,0),d=eye(2,0),f=rand(2,3,0,4)
a =
[]
b =
Empty matrix: 2-by-0
c =
Empty matrix: 2-by-0
d =
Empty matrix: 2-by-0
f =
Empty array: 2-by-3-by-0-by-4
(2)
class(a)
isnumeric(a)
isempty(a)
ans =
double
ans =
1
ans =
1
which a
ndims(a)
size(a)
a is a variable.
ans =
2
ans =
0 0
17