Octave Primer (1)

1) Modify prompt string: PS1('>>')　　

>>ps1 ('input:') Input:12

2) operation

>> 1+2
Ans=3>>1*2ans=2>>1 == 2ans=0>>1 != 2ans=1>>1 && 0ans=0>>1 || 0ans=1

3) output: disp; Formatted output with disp (sprintf (...)); Format is used to specify the length of the DISP output variable

>> A ==  3.1416>> disp3.1416disp(sprintf( ' 2 decimals:%0.2f ' , a)) 2 3.14

>> Format Long
>> A
A = 3.14159265358979

4) Matrix

>> A = [1 2;3 4;5 6]% definition matrix AA=1   2   3   4   5   6>> A = [1 2; % Definition matrix A>3 4;>5 6]a=1   2   3   4   5   6

5) Vector

>> v = [123=   1   2   3>> v = [ 1 2 3  =   1   2   3

>> v = 1:0.1:2% definition vector, starting at 1, ending at 2, each vector element incrementing by 0.1
v =

Columns 1 through 7:

1.0000 1.1000 1.2000 1.3000 1.4000 1.5000 1.6000

Columns 8 through 11:

1.7000 1.8000 1.9000 2.0000

>> v = 1:6% definition vector, starting at 1, ending with 6, incrementing each vector by 1
v =

1 2 3 4 5 6

6) Ones/zeros: Defines a matrix with all 1/0 elements

 >> ones (2 , 3  )% Definition 2 * 3 matrix, each element is 1ans  = 1  1<   /span> 1  1  1  1  >> C = 3  * Ones (2 , 3  ) C  = 3  3  3  3  3 
  

>> B = Zeros (1,3=   0   0   0>> B = zeros ( 3  =   0   0   0   0    0   0   0   0   0

7) Rand/randn: Defines the matrix where the element is a random number, where Rand is evenly distributed and RANDN is normally distributed

 >> rand (3  ) ans  = 0.77517  0.50079  0.63386  0.23687  0.89551  0.65577  0.29754  0.54136  0.68766  > > rand (2 , 3  ) ans  = 0.38275  0.67953  0.12146  0.15065  0.93036  0.95690  

 >> randn (3  ) ans  = 0.439525  1.104126 -0.725249  Span style= "color: #800080;" >0.073562  0.505057 -0.398156  Span style= "color: #800080;" >0.341471  0.719360  0.629861  > > Randn (2 , 3  ) ans  =-0.28960 -1.18585 -0.62750 -0.58217 -< Span style= "color: #800080;" >1.48229  0.25587  

8) hist (histogram) display histogram

9) Eye: Produces an n-order unit matrix

octave-3.6.4Exe One> Eye (5) ans=Diagonal Matrix1   0   0   0   0   0   1   0   0   0   0   0   1   0   0   0   0   0   1   0   0   0   0   0   1

Octave Primer (1)