3
MATLAB
.
, .
1. for.
:
for var = a1: a2: a3
end
var , a1 a3 a2 ( a2 , a2 = 1). (,) (;). , var a3.
2. while.
:
while
end
, ( , ).
.
break for while. .
return .
continue , .. for while, , . continue , .
for.
for x=1:3:10
y=x/4
end
:
y =
0.2500
y =
y =
1.7500
y =
2.5000
.
.. 57
s=0
for k=1:1:57
s=s+1./k^2;
end;
( ) -, :
for k=[2 5 7 8 11 15 25]
, k 2, 5, 7, 8, 11, 15 25.
:
A=[1 2; 3 4];
for k=A
A, .. . , .. -. , , , A:
S=0; A=[1 2; 3 4];
for k=A
S=S+sqrt(k(1)^2+k(2)^2);
end;
12 0 11 while:
i=1; t=0;
while t<=11
y(i)=sin(t)
i=i+1;
t=t+1;
end
.
s=0; k=1; u=1;
while u>1.e-8
s=s+u;
k=k+1;
u=1./k^2;
end
( ): , , while, .
|
|
, , , , Enter . Enter , (>>) . , , MATLAB , ( ). Enter. end MATLAB . , , >>.
MATLAB , , M-, , , . , ,
k=0;
for x=0:0.1:100
k=k+1;
y(k)=sin(x);
end;
x=0:0.1:100;
y=sin(x);
M-
1.4.
: , , , ,
-
nx=5; n=10;
x=[0.1; 0.3; 0.4; 0.7; 1];
s=zeros(nx,1);
line='---------------------'; % 21(-)
disp(line), disp(' x s'), disp(line) % 6()(x)10()(s)
for k=1:n
s=s+(-1)^k*x.^k/(k*(k+1));
end
disp([x s]),disp(line)
---------------------
x s
---------------------
0.1000 -0.0484
0.3000 -0.1369
0.4000 -0.1777
0.7000 -0.2886
1.0000 -0.3822
sprintf, sscanf.
(a1, a2, ) fmt s sprintf:
[s]=sprintf(fmt,a1,a2,...) |
fmt , , % (), , .
1.9.1. -.
%c | |
%d | |
%e | ( e) |
%E | ( E) |
%f | |
%g | |
%G | |
%s | |
%u |
%d %u , , MATLAB .
|
|
, fmt , , . , 1.9.2, C.
1.9.2. .
\b | (Backspace) |
\f | (Form feed) |
\n | (New line) |
\r | (Carriage return) |
\t | (Horizontal tab) |
\\ | (Backslash) |
\'' | (') |
%% | (%) |
MATLAB (, ):
>> sprintf('%-7d %+7d %07d',12345,12345,12345) ans = 12345 +12345 0012345 >> sprintf('% d',12345) ans = >> sprintf('% d',-12345) ans = -12345 >> sprintf('%10.6f',pi) ans = 3.141593 >> sprintf('%9.5f',pi) ans = 3.14159 >> sprintf('%d',pi) ans = 3.141593e+00 >> sprintf(' =%10.8f',pi) ans = =3.14159265 |
s, sprintf, sscanf:
A=sscanf(s,fmt) |
fmt. , .
:
, *, s;
%hd, %ld %lg,
(%hd), (%ld) (%lg);
%[s1s2...], s, ;
%[^s1s2...], s, .
(, ):
>> s='2.7183 3.1416'; >> A=sscanf(s,'%f') A = 2.7183 3.1416 |
, A :
>> s1=sprintf('%f ',A) s1 = 2.718300 3.141600 |
. , .
>> s1=sprintf('%f',A) s1 = 2.7183003.141600 |