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Return an identity matrix. If invoked with a single scalar argument,
eyereturns a square matrix with the dimension specified. If you supply two scalar arguments,eyetakes them to be the number of rows and columns. If given a vector with two elements,eyeuses the values of the elements as the number of rows and columns, respectively. For example,eye (3) => 1 0 0 0 1 0 0 0 1The following expressions all produce the same result:
eye (2) == eye (2, 2) == eye (size ([1, 2; 3, 4])The optional argument class, allows
eyeto return an array of the specified type, likeval = zeros (n,m, "uint8")For compatibility with Matlab, calling
eyewith no arguments is equivalent to calling it with an argument of 1.
Return a matrix or N-dimensional array whose elements are all 1. The arguments are handled the same as the arguments for
eye.If you need to create a matrix whose values are all the same, you should use an expression like
val_matrix = val * ones (n, m)The optional argument class, allows
onesto return an array of the specified type, likeval = ones (n,m, "uint8")
Return a matrix or N-dimensional array whose elements are all 0. The arguments are handled the same as the arguments for
eye.The optional argument class, allows
zerosto return an array of the specified type, likeval = zeros (n,m, "uint8")
Form a block matrix of size m by n, with a copy of matrix A as each element. If n is not specified, form an m by m block matrix.
"seed", x)Return a matrix with random elements uniformly distributed on the interval (0, 1). The arguments are handled the same as the arguments for
eye. In addition, you can set the seed for the random number generator using the formrand ("seed", x)where x is a scalar value. If called as
rand ("seed")
randreturns the current value of the seed.
"seed", x)Return a matrix with normally distributed random elements. The arguments are handled the same as the arguments for
eye. In addition, you can set the seed for the random number generator using the formrandn ("seed", x)where x is a scalar value. If called as
randn ("seed")
randnreturns the current value of the seed.
The rand and randn functions use separate generators.
This ensures that
rand ("seed", 13);
randn ("seed", 13);
u = rand (100, 1);
n = randn (100, 1);
and
rand ("seed", 13);
randn ("seed", 13);
u = zeros (100, 1);
n = zeros (100, 1);
for i = 1:100
u(i) = rand ();
n(i) = randn ();
end
produce equivalent results.
Normally, rand and randn obtain their initial
seeds from the system clock, so that the sequence of random numbers is
not the same each time you run Octave. If you really do need for to
reproduce a sequence of numbers exactly, you can set the seed to a
specific value.
If it is invoked without arguments, rand and randn return a
single element of a random sequence.
The rand and randn functions use Fortran code from
Ranlib, a library of fortran routines for random number generation,
compiled by Barry W. Brown and James Lovato of the Department of
Biomathematics at The University of Texas, M.D. Anderson Cancer Center,
Houston, TX 77030.
Return a row vector containing a random permutation of the integers from 1 to n.
Return a diagonal matrix with vector v on diagonal k. The second argument is optional. If it is positive, the vector is placed on the k-th super-diagonal. If it is negative, it is placed on the -k-th sub-diagonal. The default value of k is 0, and the vector is placed on the main diagonal. For example,
diag ([1, 2, 3], 1) => 0 1 0 0 0 0 2 0 0 0 0 3 0 0 0 0
The functions linspace and logspace make it very easy to
create vectors with evenly or logarithmically spaced elements.
See Ranges.
Return a row vector with n linearly spaced elements between base and limit. The number of elements, n, must be greater than 1. The base and limit are always included in the range. If base is greater than limit, the elements are stored in decreasing order. If the number of points is not specified, a value of 100 is used.
The
linspacefunction always returns a row vector.
Similar to
linspaceexcept that the values are logarithmically spaced from 10^base to 10^limit.If limit is equal to pi, the points are between 10^base and pi, not 10^base and 10^pi, in order to be compatible with the corresponding Matlab function.