1.
>> a = [1 2 3 4 6 4 3 4 5], // 9
a =
1 2 3 4 6 4 3 4 5 //
>> b = a + 2, // , b = a + 2
b =
3 4 5 6 8 6 5 6 7 //
MATLAB . , ,
>> a = [1 2 3 4 6 4 3 4 5];
>> b = a + 2;
>> plot(b)
>> grid
MATLAB : , , .
>> bar(b),
, MATLAB - , . , , , ";" .
>> A = [1 2 0; 2 5 -1; 4 10 -1]
A =
1 2 0
2 5 -1
4 10 -1
>> B = [1 2 3; 4 5 6; 7 8 9]
B =
1 2 3
4 5 6
7 8 9
- (.*)
>> C=A.*B
C =
1 4 0
8 25 -6
28 80 -9
, , :
>> V=[1 2 3]
>> V= [2+2/(3+4) exp(5) sqrt(10)]
V = 2.2857 148.4132 3.1623
V(1) M(i, j). ,
>> m=[10 20 30; 40 50 60; 70 80 90]
m =
10 20 30
40 50 60
70 80 90
..
>> m(1,1)
ans = 10
>> m(3,2)
ans = 80
>> m(1,3)
ans = 30
, m(2, 2) -6,
m(2,2)=-6
(:) .
>> m(:)
(i) , . , .
| 10 20 30 40 50 60 70 -6 90 | -6 |
> m(3)
ans = 70
>> m(4)
ans = 20
>> m(6)
ans = -6
>> m(8)=100
m =
10 20 30
40 50 100
70 -6 90
. [ ]. : ():
|
|
|
>> m(:,2)=[]
m =
10 30
40 100
70 90
, : (), :
>> m(2,:)=[]
m =
10 30
70 90
:
- sum(A) , , -, , ;
- sum(A.dim) (dim-1), (dim=2) dim.
:
| A=magic(4) | ||
| = | ||
| 16 2 | ||
| 5 11 | ||
| 9 7 | ||
| 4 14 | ||
| B=sum(A) | ||
| = |
34 34 34 34
- cumsum(A) . , cumsum(A) , . , cumsum(A) , , ;
- cumsum(A.dim) , dim. , cumsum(A.l) .
:
A=magic(4)
=
16 2 3 13
5 11 10 8
9 7 6 12
4 14 15 1
= cumsum(A)
=
16 2 3 13
21 13 13 21
30 20 19 33
34 34 34 34
. :
- tril(X) , X , , ;
- tril(X.k) X k- . k=0 , k>0 , k<0 .
:
=[3.1.4:8.3.2;8.1.1]
=
3 1 4
8 3 2
8 1 1
tril(M)
ans =
3 0 0
8 3 0
8 1 1
- triu(X) X , ;
- triu(X.k) X k- . k=0 , k>0 , k<0 .
:
=
3 1 4
8 3 2
8 1 1
triu(M)
ans =
3 1 4
0 3 2
0 0 1
