r = rem(a,b) returns
the remainder after division of a by b,
where a is the dividend and b is
the divisor. This operation is conceptually equal to r =
a - b.*fix(a./b), which uses different rounding than the mod function.
The rem function follows the convention that rem(a,0) is NaN.

Find the remainder after division for a set of integers including both positive and negative values. Note that nonzero results have the same sign as the dividend.

Find the remainder after division for several angles using a divisor of 2*pi. When possible, rem attempts to produce exact integer results by comepensating for floating-point round-off effects.

theta = [0.0 3.5 5.9 6.2 9.0 4*pi];
b = 2*pi;
r = rem(theta,b)

a — Dividendscalar | vector | matrix | multidimensional array

Dividend, specified as a scalar, vector, matrix, or multidimensional
array. a must be a real-valued array of any numerical
type. Inputs a and b must be
the same size unless one is a scalar. A scalar value expands to be
the same size as the other array.

If one input has an integer data type, then the other input
must be of the same integer data type or be a scalar double.

b — Divisorscalar | vector | matrix | multidimensional array

Divisor, specified as a scalar, vector, matrix, or multidimensional
array. b must be a real-valued array of any numerical
type. Inputs a and b must be
the same size unless one is a scalar. A scalar value expands to be
the same size as the other array.

If one input has an integer data type, then the other input
must be of the same integer data type or be a scalar double.

The concept of remainder after division is
not uniquely defined, and the two functions mod and rem each
compute a different variation. The mod function
produces a result that is either zero or has the same sign as the
divisor. The rem function produces a result that
is either zero or has the same sign as the dividend.

Another difference is the convention when the divisor is zero.
The mod function follows the convention that mod(a,0) returns a,
whereas the rem function follows the convention
that rem(a,0) returns NaN.

Both variants have their uses. For example, in signal processing,
the mod function is useful in the context of
periodic signals because its output is periodic (with period equal
to the divisor).