% scripts and MATLAB functions are stored
% in files ending with ".m".  We can place
% the scripts in the current directory, where
% MATLAB will find them, or change the path
path

		MATLABPATH

	N:\MATLAB~1\toolbox\matlab\general
	N:\MATLAB~1\toolbox\matlab\ops
	N:\MATLAB~1\toolbox\matlab\lang
	N:\MATLAB~1\toolbox\matlab\elmat
	N:\MATLAB~1\toolbox\matlab\elfun
	N:\MATLAB~1\toolbox\matlab\specfun
	N:\MATLAB~1\toolbox\matlab\matfun
	N:\MATLAB~1\toolbox\matlab\datafun
	N:\MATLAB~1\toolbox\matlab\polyfun
	N:\MATLAB~1\toolbox\matlab\funfun
	N:\MATLAB~1\toolbox\matlab\sparfun
	N:\MATLAB~1\toolbox\matlab\scribe
	N:\MATLAB~1\toolbox\matlab\graph2d
	N:\MATLAB~1\toolbox\matlab\graph3d
	N:\MATLAB~1\toolbox\matlab\specgraph
	N:\MATLAB~1\toolbox\matlab\graphics
	N:\MATLAB~1\toolbox\matlab\uitools
	N:\MATLAB~1\toolbox\matlab\strfun
	N:\MATLAB~1\toolbox\matlab\imagesci
	N:\MATLAB~1\toolbox\matlab\iofun
	N:\MATLAB~1\toolbox\matlab\audiovideo
	N:\MATLAB~1\toolbox\matlab\timefun
	N:\MATLAB~1\toolbox\matlab\datatypes
	N:\MATLAB~1\toolbox\matlab\verctrl
	N:\MATLAB~1\toolbox\matlab\codetools
	N:\MATLAB~1\toolbox\matlab\helptools
	N:\MATLAB~1\toolbox\matlab\winfun
	N:\MATLAB~1\toolbox\matlab\demos
	N:\MATLAB~1\toolbox\local
	N:\MATLAB~1\toolbox\simulink\simulink
	N:\MATLAB~1\toolbox\simulink\blocks
	N:\MATLAB~1\toolbox\simulink\components
	N:\MATLAB~1\toolbox\simulink\fixedandfloat
	N:\MATLAB~1\toolbox\simulink\fixedandfloat\fxpdemos
	N:\MATLAB~1\toolbox\simulink\fixedandfloat\obsolete
	N:\MATLAB~1\toolbox\simulink\simdemos
	N:\MATLAB~1\toolbox\simulink\simdemos\aerospace
	N:\MATLAB~1\toolbox\simulink\simdemos\automotive
	N:\MATLAB~1\toolbox\simulink\simdemos\simfeatures
	N:\MATLAB~1\toolbox\simulink\simdemos\simfeatures\mdlref
	N:\MATLAB~1\toolbox\simulink\simdemos\simgeneral
	N:\MATLAB~1\toolbox\simulink\simdemos\simnew
	N:\MATLAB~1\toolbox\simulink\dee
	N:\MATLAB~1\toolbox\shared\dastudio
	N:\MATLAB~1\toolbox\stateflow\stateflow
	N:\MATLAB~1\toolbox\rtw\rtw
	N:\MATLAB~1\toolbox\shared\hds
	N:\MATLAB~1\toolbox\shared\timeseries
	N:\MATLAB~1\toolbox\stateflow\sfdemos
	N:\MATLAB~1\toolbox\stateflow\coder
	N:\MATLAB~1\toolbox\control\control
	N:\MATLAB~1\toolbox\control\ctrlguis
	N:\MATLAB~1\toolbox\control\ctrlobsolete
	N:\MATLAB~1\toolbox\control\ctrlutil
	N:\MATLAB~1\toolbox\control\ctrldemos
	N:\MATLAB~1\toolbox\shared\controllib
	N:\MATLAB~1\toolbox\ident\ident
	N:\MATLAB~1\toolbox\ident\idobsolete
	N:\MATLAB~1\toolbox\ident\idguis
	N:\MATLAB~1\toolbox\ident\idutils
	N:\MATLAB~1\toolbox\ident\iddemos
	N:\MATLAB~1\toolbox\ident\idhelp
	N:\MATLAB~1\toolbox\images\images
	N:\MATLAB~1\toolbox\images\imuitools
	N:\MATLAB~1\toolbox\images\imdemos
	N:\MATLAB~1\toolbox\images\iptutils
	N:\MATLAB~1\toolbox\nnet\nnet
	N:\MATLAB~1\toolbox\nnet\nnutils
	N:\MATLAB~1\toolbox\nnet\nncontrol
	N:\MATLAB~1\toolbox\nnet\nndemos
	N:\MATLAB~1\toolbox\nnet\nnobsolete
	N:\MATLAB~1\toolbox\optim
	N:\MATLAB~1\toolbox\shared\optimlib
	N:\MATLAB~1\toolbox\pde
	N:\MATLAB~1\toolbox\signal\signal
	N:\MATLAB~1\toolbox\signal\sigtools
	N:\MATLAB~1\toolbox\signal\sptoolgui
	N:\MATLAB~1\toolbox\signal\sigdemos
	N:\MATLAB~1\toolbox\stats
	N:\MATLAB~1\toolbox\symbolic
	N:\MATLAB~1\toolbox\wavelet\wavelet
	N:\MATLAB~1\toolbox\wavelet\wavedemo
pwd % print working directory

ans =

C:\Documents and Settings\janv

edit
fschange('C:\Documents and Settings\janv\my_script.m');
clear('C:\Documents and Settings\janv\my_script.m');
% We just created a funtion stored in my_script
% to see if MATLAB can get to my_script, we type
help my_script
  returns the sum of a and b



my_script(3,4)

ans =

     7

% By default, the current directory was in the
% matlabpath, otherwise, if my_script was save
% somewhere else, we had to adjust the path.
% The next example is an interactive function,
% to compute the area of a circle.  The user is
edit
fschange('C:\Documents and Settings\janv\areacircle.m');
clear('C:\Documents and Settings\janv\areacircle.m');
% prompted to give the radius.
areacircle
Give the radius : 45
The area of circle with radius 45.00 is 6361.725124 
edit
fschange('C:\Documents and Settings\janv\traprule.m');
clear('C:\Documents and Settings\janv\traprule.m');
% We just created a function "traprule"
% to implement the trapezoidal rule
help traprule
 
  DESCRIPTION :
    Returns the trapezoidal rule to approximate
    the integral of f over [a,b].
 



% suppose we want to approximate the integral
% of cos(x) for x in [0,1]
t = traprule(cos,0,1) 
??? Error using ==> cos
Not enough input arguments.

Error in ==> <a href="error:N:\MATLAB~1\toolbox\matlab\elfun\cos.m,14,1">cos at 14</a>
  [varargout{1:nargout}] = builtin('cos', varargin{:});

% To give a function name as argument to another
% function, we must pass it as a string:
t = traprule('cos',0,1)

t =

    0.7702

% Let us implement the composite trapezoidal rule
edit
fschange('C:\Documents and Settings\janv\comptrap.m');
clear('C:\Documents and Settings\janv\comptrap.m');
% to improve approximation.
t = comptrap('cos',0,1,1)

t =

    0.7702

t = comptrap('cos',0,1,2)

t =

    0.8239

t = comptrap('cos',0,1,3)

t =

    0.8337

t = comptrap('cos',0,1,4)

t =

    0.8371

format long e
for n = 1:10
     t = comptrap('cos',0,1,n)
end;

t =

    7.701511529340699e-001


t =

    8.238668574122213e-001


t =

    8.336651200085851e-001


t =

    8.370837513522271e-001


t =

    8.386642098070081e-001


t =

    8.395222329270183e-001


t =

    8.400394247082814e-001


t =

    8.403750340273868e-001


t =

    8.406050957359873e-001


t =

    8.407696420884199e-001

help quad
 QUAD   Numerically evaluate integral, adaptive Simpson quadrature.
    Q = QUAD(FUN,A,B) tries to approximate the integral of function
    FUN from A to B to within an error of 1.e-6 using recursive
    adaptive Simpson quadrature.  The function Y = FUN(X) should
    accept a vector argument X and return a vector result Y, the
    integrand evaluated at each element of X.  
 
    Q = QUAD(FUN,A,B,TOL) uses an absolute error tolerance of TOL 
    instead of the default, which is 1.e-6.  Larger values of TOL
    result in fewer function evaluations and faster computation,
    but less accurate results.  The QUAD function in MATLAB 5.3 used
    a less reliable algorithm and a default tolerance of 1.e-3.
 
    [Q,FCNT] = QUAD(...) returns the number of function evaluations.
 
    QUAD(FUN,A,B,TOL,TRACE) with non-zero TRACE shows the values
    of [fcnt a b-a Q] during the recursion.
 
    QUAD(FUN,A,B,TOL,TRACE,P1,P2,...) provides for additional 
    arguments P1, P2, ... to be passed directly to function FUN,
    FUN(X,P1,P2,...).  Pass empty matrices for TOL or TRACE to
    use the default values.
 
    Use array operators .*, ./ and .^ in the definition of FUN
    so that it can be evaluated with a vector argument.
 
    Function QUADL may be more efficient with high accuracies
    and smooth integrands.
 
    Example:
        FUN can be specified as:
 
        An anonymous function:
           F = @(x) 1./(x.^3-2*x-5);
           Q = quad(F,0,2);
 
        A function handle:
           Q = quad(@myfun,0,2);
           where myfun.m is an M-file:
              function y = myfun(x)
              y = 1./(x.^3-2*x-5);
 
    Class support for inputs A, B, and the output of FUN: 
       float: double, single
 
    See also <a href="matlab:help quadv">quadv</a>, <a href="matlab:help quadl">quadl</a>, <a href="matlab:help dblquad">dblquad</a>, <a href="matlab:help triplequad">triplequad</a>, @, <a href="matlab:help trapz">trapz</a>.


    Reference page in Help browser
       <a href="matlab:doc quad">doc quad</a>



quad('cos',0,1)

ans =

    8.414709828359894e-001

comptrap('cos',0,1,100)

ans =

    8.414639725380023e-001

f = inline('x^7 + 3*x + 1')

f =

     Inline function:
     f(x) = x^7 + 3*x + 1

f(3)

ans =

        2197

comptrap(f,0,1,9)

ans =

    2.632157348291407e+000

diary off