octave:3> randi(10)
ans =  6
octave:4> randi(10)
ans =  8
octave:5> randi(10)
ans =  8
octave:6> randi(10)
ans =  5
octave:7> randi(10)
ans =  5
octave:8> randi(10)
ans =  10
octave:9> randexp(1)
ans =  1.1759
octave:10> randexp([1,2])
ans =

   0.13524   0.42576

octave:11> randexp([1,1])
ans =

   0.36203   0.13617

octave:12> randexp([1,2])
ans =

   1.22416   0.15220

octave:13> randexp([ones(1,10),2*ones(1,10)])
ans =

 Columns 1 through 6:

   1.6790e+00   2.0781e+00   1.2434e+00   1.4448e-01   3.3616e+00   2.5132e-01

 Columns 7 through 12:

   2.2179e+00   8.1158e-01   7.8417e-01   9.1867e-01   5.1650e-04   8.2149e-01

 Columns 13 through 18:

   7.6127e-01   4.6393e-03   7.3359e-02   1.9372e+00   3.0715e-01   3.5326e-01

 Columns 19 and 20:

   1.4502e+00   1.0698e-02

octave:14> help rande
'rande' is a built-in function from the file libinterp/corefcn/rand.cc

 -- Built-in Function: rande (N)
 -- Built-in Function: rande (M, N, ...)
 -- Built-in Function: rande ([M N ...])
 -- Built-in Function: V = rande ("state")
 -- Built-in Function: rande ("state", V)
 -- Built-in Function: rande ("state", "reset")
 -- Built-in Function: V = rande ("seed")
 -- Built-in Function: rande ("seed", V)
 -- Built-in Function: rande ("seed", "reset")
 -- Built-in Function: rande (..., "single")
 -- Built-in Function: rande (..., "double")
     Return a matrix with exponentially distributed random elements.
     The arguments are handled the same as the arguments for 'rand'.

     By default, 'randn' uses the Marsaglia and Tsang "Ziggurat
     technique" to transform from a uniform to an exponential
     distribution.

     The class of the value returned can be controlled by a trailing
     "double" or "single" argument.  These are the only valid classes.

     Reference: G. Marsaglia and W.W. Tsang, 'Ziggurat Method for
     Generating Random Variables', J. Statistical Software, vol 5, 2000,
     <http://www.jstatsoft.org/v05/i08/>)

     See also: rand, randn, randg, randp.


Additional help for built-in functions and operators is
available in the online version of the manual.  Use the command
'doc <topic>' to search the manual index.

Help and information about Octave is also available on the WWW
at http://www.octave.org and via the help@octave.org
mailing list.
octave:15> sin(pi)
ans =    1.2246e-16
octave:16> demo testva
testva example 1:
 testva (@randexp, 3*ones(1000,1))

octave:17> testva (@randexp, 3*ones(1000,1))
octave:18> close all
octave:19> testva (@randexp, 3*ones(1000,1))
octave:20> close all,testva (@randnorm, zeros(1000,1),ones(1000,1))
octave:21> close all,testva (@randnorm, zeros(1000,1),ones(1000,1))
octave:22> close all,testva (@randnorm, zeros(10000,1),ones(10000,1))
octave:23> close all,testva (@randnorm, zeros(1000,1),ones(1000,1))
octave:24> close all,testva (@randnorm, zeros(100,1),ones(100,1))
octave:25> close all,testva (@randnorm, zeros(100,1),ones(100,1))
octave:26> close all
octave:27> simulacodamm1
Elapsed time is 19.8809 seconds.
Elapsed time is 20.9155 seconds.
octave:28> simulacodamm1
Elapsed time is 19.7247 seconds.
Elapsed time is 19.4157 seconds.
octave:29> simulacodamm1
Elapsed time is 19.2483 seconds.
Elapsed time is 17.8319 seconds.
octave:30> simulacodamm1
Elapsed time is 39.4139 seconds.
Elapsed time is 35.0908 seconds.
octave:31> help randi
'randi' is a function from the file /usr/share/octave/3.8.1/m/general/randi.m

 -- Function File: randi (IMAX)
 -- Function File: randi (IMAX, N)
 -- Function File: randi (IMAX, M, N, ...)
 -- Function File: randi ([IMIN IMAX], ...)
 -- Function File: randi (..., "CLASS")
     Return random integers in the range 1:IMAX.

     Additional arguments determine the shape of the return matrix.
     When no arguments are specified a single random integer is
     returned.  If one argument N is specified then a square matrix (N x N)
     is returned.  Two or more arguments will return a multi-dimensional
     matrix (M x N x ...).

     The integer range may optionally be described by a two element
     matrix with a lower and upper bound in which case the returned
     integers will be on the interval [IMIN, IMAX].

     The optional argument CLASS will return a matrix of the requested
     type.  The default is "double".

     The following example returns 150 integers in the range 1-10.

          ri = randi (10, 150, 1)

     Implementation Note: 'randi' relies internally on 'rand' which uses
     class "double" to represent numbers.  This limits the maximum
     integer (IMAX) and range (IMAX - IMIN) to the value returned by the
     'bitmax' function.  For IEEE floating point numbers this value is
     2^{53} - 1.

     See also: rand.


Additional help for built-in functions and operators is
available in the online version of the manual.  Use the command
'doc <topic>' to search the manual index.

Help and information about Octave is also available on the WWW
at http://www.octave.org and via the help@octave.org
mailing list.
octave:32> 6004799503160661
ans =    6.0048e+15
octave:33> intmax
ans = 2147483647
octave:34> a = randi(6004799503160661,10000,1);
octave:35> size(a)
ans =

   10000       1

octave:36> length(find(mod(a,2)==0))
ans =  4624
octave:37> mod(3,2)
ans =  1
octave:38> mod(4,2)
ans = 0
octave:39> length(find(mod(a,2)==1))
ans =  5376
octave:40> a = randi(6004799503160661,10000,1);
octave:41> length(find(mod(a,2)==1))
ans =  5408
octave:42> length(find(mod(a,2)==0))
ans =  4592
octave:43> diary off