help.op

C 开发的有限元软件

op = op :=
X = Y
X := Y

    Assigns Y to X and returns X.  X must be a variable name, a subsection
    of a matrix (submatrix), or the result of a function call returning a
    global variable.  If X is a submatrix then the dimensions of Y must
    match the dimensions of X.


op || op or
m || n
m or n

    If m evaluates to true (non-zero) then one is returned.  Otherwise, n is
    evaluated and if n is false then zero is returned.  If n is true
    (non-zero) then one is returned.  Both m and n must be scalars.


op && op and
m && n
m and n

    If m evaluates to false (zero) then zero is returned.  Otherwise, n is
    evaluated and if n is false then zero is returned.  If n is true
    (non-zero) then one is returned.  Both m and n must be scalars.


op ==
X == Y

    Compares each element of X against each element of Y and sets the
    corresponding element of the result to one if X is equal to Y, and zero
    otherwise.  If both X and Y are matrices then their dimensions must
    match.


op != op <>
X != Y
X <> Y

    Compares each element of X against each element of Y and sets the
    corresponding element of the result to one if X is not equal to Y, and
    zero otherwise.  If both X and Y are matrices then their dimensions must
    match.


op <
X < Y

    Compares each element of X against each element of Y and sets the
    corresponding element of the result to one if X is less than to Y, and
    zero otherwise.  If both X and Y are matrices then their dimensions must
    match.


op >
X > Y

    Compares each element of X against each element of Y and sets the
    corresponding element of the result to one if X is greater than Y, and
    zero otherwise.  If both X and Y are matrices then their dimensions must
    match.


op <=
X <= Y

    Compares each element of X against each element of Y and sets the
    corresponding element of the result to one if X is less than or equal to
    Y, and zero otherwise.  If both X and Y are matrices then their
    dimensions must match.


op >=
X >= Y

    Compares each element of X against each element of Y and sets the
    corresponding element of the result to one if X is greater than or equal
    to Y, and zero otherwise.  If both X and Y are matrices then their
    dimensions must match.


op :
m : n
m : k : n

    Returns a row vector starting with values m through n.  If k is given
    then it is used as the increment between successive values.  Otherwise,
    the increment is one.


op +
+ X
X + Y

    In the unary form, returns X.  In the binary form, returns the sum of X
    and Y.  If X and Y are both scalars then scalar addition is performed.
    If one is a scalar and the other is a matrix then the scalar value is
    added to each element of the matrix.  If both are matrices then matrix
    addition is performed, and the dimensions of each must agree.


op -
- X
X - Y

    In the unary form, returns the negative of X.  In the binary form,
    returns the difference of X and Y.  If X and Y are both scalars then
    subtraction is performed.  If X is a matrix and Y is a scalar then Y is
    subtracted from each element of X.  If X is a scalar and Y is a matrix
    then each element of X is subtracted from Y.  If both are matrices then
    matrix subtraction is performed, and the dimensions of each must agree.


op *
X * Y

    Returns the product of X and Y.  If X and Y are both scalars then scalar
    multiplication is performed.  If one is a scalar and the other is a
    matrix then the matrix is scaled by the scalar value.  If both are
    matrices then the matrix multiplication is performed, and the inner
    dimensions must agree.


op \
X \ Y

    Returns the "left division" of X and Y, or (1/X) * Y.  If X and Y are
    matrices then an LU decomposition is used to compute the "inverse" of X.
    If X is a matrix but Y is a scalar then the true inverse of X is scaled
    by Y.


op /
X / Y

    Returns the "right division" of X and Y, or X * (1/Y).  If X and Y are
    matrices then an LU decomposition (along with transposition) is used to
    compute the "inverse" of Y.  If X is a scalar but Y is a matrix then the
    true inverse of Y is scaled by X.


op % func fmod
X % Y
fmod (X, Y)

    Returns the modulo of X and Y.  If X and Y are both scalars then the
    scalar remainder is computed.  If X is a matrix and Y is a scalar then
    each element of X is computed modulo Y.  If X is a scalar and Y is a
    matrix then X is computed modulo each element of Y.  If both are
    matrices then each element of X is computed modulo each element of Y,
    and the dimensions of each must agree.


op ^ op ** func pow
m ^ n
m ** n
pow (m, n)

    Returns m raised to the power n, where m is non-negative or n is an
    integer value.  Both m and n must be scalars.


op '
X '

    Returns the transpose of X.  The transpose of a scalar is itself.


op ! op not
! X
not X

    Returns the logical negation of X.  If X is a matrix then each element
    of X is negated.  The logical negation of zero is one and the logical
    negation of a non-zero value is zero.


op ( op ) op ()
( X )
X ( ... )

    In the first form, which may be used for enforcing precedence, the
    result is X.  In the second form, if X is a matrix then the result is a
    subsection of the matrix (submatrix).  The number of indices must be
    appropriate.  If an index is a vector then it designates a series of
    rows or columns and must be contiguous.  The special index : may be used
    to designate an entire row or column.  If X is an array then the return
    value is the result of indexing the array.  Otherwise, X is evaluated as
    a function and the remaining expressions are passed as arguments.  The
    result is the return value of the function call.


op [ op ] op []
[ ... ; ... ; ... ]

    Returns a matrix.  A semicolon (or return) separates one row for the
    next.  Matrix elements on the same row are separated with commas.  The
    matrix elements may be matrices or scalars, but all elements on the same
    row must have the same number of rows.  Each row must also have the same
    number of columns.


op .
X . id

    Returns the field id of structure X.  This operator is used to access
    members of the FElt data structures.