Arithmetic

Purpose

Apply simple arithmetic operations to all or part of dataset.

Synopsis

[cx] = arithmetic(x);

[cx] = arithmetic(x, op, const);

[cx] = arithmetic(x, op, const, indices);

[cx] = arithmetic(x, op, const, indices, modes);

Description

Apply an arithmetic operation to the input dataset or array (n-way), or a specified subset thereof. The supported operations are listed below. These are applied element-wise, so 'multiply' is applied as '.*' for example. The operation is applied to x or the specified subset of x.

Available operations:

% add      : Adds const.                        xij = xij+const
% subtract : Subtract const.                    xij = xij-const
% multiply : Multiply by const.                 xij = xij*const
% divide   : Divide by const.                   xij = xij/const
% inverse  : Invert and multiply by const.      xij = const/xij
% power    : Raise to power of const.           xij = xij^const
% root     : Take const root.                   xij = xij^(1/const)
% modulus  : Modulus after division by const.   xij = mod(xij,const)
% round    : Round to nearest 1/const fraction. xij = round(xij*const)/const
% log      : Log to base const.                 xij = log(xij)/log(const)
% antilog  : Antilog to base const.             xij = const^(xij)
% noop     : Identity op. Make no change.       xij = xij

Inputs

• x = dataset or array.

Optional Inputs

• operation = name (char) of arithmetic operation to apply.
• const = value (double) used in the operation.
• indices = a cell of requested indices (e.g. {[1:5] [10:20]} ).
• modes = Modes (integer, or vector) to which indicies should be applied. See nindex/nassign for indices and modes usage.

Outputs

• cx = modified dataset or array.

Options

options = a structure array with the following fields:

• isundo: [ 'yes' | {'no'} ] Change operation to undo mode.

See Also

nindex, preprocess