(lispkit math util)

Library (lispkit math util) implements mathematical utility functions.

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(sgn x)

Implements the sign/signum function. Returns -1 if x is negative, 0 (or a signed zero, when inexact) if x is zero, and 1 if x is a positive number. sgn fails if x is not a real number.

(numbers lo hi) (numbers lo hi f) (numbers lo hi guard f)

Returns a list of numbers by iterating from integer lo to integer hi (both inclusive) and applying function f to each integer in the range for which guard returns true. The default guard always returns true. The default for f is identity.

(sum xs)

Returns the sum of all numbers of list xs. This procedure fails if there is an element in xs which is not a number.

(product xs)

Returns the product of all numbers of list xs. This procedure fails if there is an element in xs which is not a number.

(minimum xs)

Returns the minimum of all numbers of list xs. This procedure fails if there is an element in xs which is not a number.

(maximum xs)

Returns the maximum of all numbers of list xs. This procedure fails if there is an element in xs which is not a number.

(conjugate x)

Conjugates number x. For real numbers x, conjugate returns x, otherwise x is being returned with the opposite sign for the imaginary part.

(degrees->radians x)

Converts degrees into radians.

(radians->degrees x)

Converts radians into degrees.

(prime? n)

Returns #t if integer n is a prime number, #f otherwise.

(make-nan neg quiet payload)

Returns a NaN whose sign bit is equal to neg (#t for negative, #f for positive), whose quiet bit is equal to quiet (#t for quiet, #f for signaling), and whose payload is the positive exact integer payload. It is an error if payload is larger than a NaN can hold.

(nan-negative? x)

Returns #t if the sign bit of x is 1 and #f otherwise.

(nan-quiet? x)

Returns #t if x is a quiet NaN.

(nan-payload x)

Returns the payload bits of floating-point number x as a positive exact integer.

(nan=? x y)

Returns #t if x and y have the same sign, quiet bit, and payload; and #f otherwise.