2matlab基本使用方法

(12+2*(7-4))/3^2

ans =

2

format short;pi

ans =

3.1416

format long;pi

ans =

3.141592653589793

format rat;pi

ans =

355/113

format long;vpa(pi,50)

ans =

3.141592653589793115997963468544185161590576171875

who

Your variables are:

ans

a=randn(4)

a =

-0.1241 0.6715 0.4889 0.2939

1.4897 -1.2075 1.0347 -0.7873

1.4090 0.7172 0.7269 0.8884

1.4172 1.6302 -0.3034 -1.1471

whos

Name Size Bytes Class Attributes

a 4x4 128 double

ans 1x1 8 double

who

Your variables are:

a ans

what

M-files in the current directory E:\Matlab2010\智能仿生算法\遗传算法TSP_SuiJiSuanFa ZhuanJiaXiTongP167 fun_SuiJiSuanFa TSPrun_SuiJiSuanFa f fun_SuiJiSuanFa0

ZhuanJiaXiTongP162 f1 fun_SuiJiSuanFa2

MAT-files in the current directory E:\Matlab2010\智能仿生算法\遗传算法

my27city

dir

. ZhuanJiaXiTongP162.asv f.m my27city.mat

.. ZhuanJiaXiTongP162.m f1.m temp

3d.asv ZhuanJiaXiTongP167.asv fun_SuiJiSuanFa.asv temp.prj

3d.m ZhuanJiaXiTongP167.m fun_SuiJiSuanFa.m zia03836

New Folder bou2_4l.shp fun_SuiJiSuanFa0.asv TSP_SuiJiSuanFa.m da fun_SuiJiSuanFa0.m TSPrun_SuiJiSuanFa.m da.prj fun_SuiJiSuanFa2.m type 3d

clf;

x=-3:0.1:3;

y=-3:0.1:3;

[X Y]=meshgrid(x,y);

Z=f(X,Y)+4;

mesh(X,Y,Z);

hold on;

plot3(-0.7,-1,f(-0.7,-1)+4,'g*');

contour(X,Y,Z,'r');

which rand

built-in (D:\Program Files\MATLAB\R2010a\toolbox\matlab\randfun\rand) which 3d.m

E:\Matlab2010\智能仿生算法\遗传算法\3d.m

help exist

EXIST Check if variables or functions are defined.

EXIST('A') returns:

0 if A does not exist

1 if A is a variable in the workspace

2 if A is an M-file on MATLAB's search path. It also returns 2 when

A is the full pathname to a file or when A is the name of an ordinary file on MATLAB's search path

3 if A is a MEX-file on MATLAB's search path

4 if A is a MDL-file on MATLAB's search path

5 if A is a built-in MATLAB function

6 if A is a P-file on MATLAB's search path

7 if A is a directory

8 if A is a Java class

EXIST('A') or EXIST('A.EXT') returns 2 if a file named 'A' or

'A.EXT'

and the extension isn't a P or MEX function extension.

EXIST('A','var') checks only for variables.

EXIST('A','builtin') checks only for built-in functions.

EXIST('A','file') checks for files or directories.

EXIST('A','dir') checks only for directories.

EXIST('A','class') checks only for Java classes.

If A specifies a filename, MATLAB attempts to locate the file,

examines the filename extension, and determines the value to

return based on the extension alone. MATLAB does not examine

the contents or internal structure of the file.

When searching for a directory, MATLAB finds directories that are part

of MATLAB's search path. They can be specified by a partial path. It

also finds the current working directory specified by a partial path,

and subdirectories of the current working directory specified by

a relative path.

EXIST returns 0 if the specified instance isn't found.

See also DIR, WHAT, ISEMPTY, PARTIALPATH.

Overloaded methods:

inline/exist

fittype/exist

Composite/exist

Reference page in Help browser

doc exist

matlabroot

ans =

D:\Program Files\MATLAB\R2010a

diary('myJog')

c=rand(5)

c =

0.1839 0.9448 0.3692 0.4039 0.5752

0.2400 0.4909 0.1112 0.0965 0.0598

0.4173 0.4893 0.7803 0.1320 0.2348

0.0497 0.3377 0.3897 0.9421 0.3532

0.9027 0.9001 0.2417 0.9561 0.8212

diary off

d=randn(6)

d =

-1.3320 -0.1303 -0.8487 0.6601 0.0513 0.1832

-2.3299 0.1837 -0.3349 -0.0679 0.8261 -1.0298