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Improved README to follow standard for contrib

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Signed-off-by: Christian Romney <>
Signed-off-by: Sean Corfield <>
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christianromney authored and seancorfield committed Sep 17, 2012
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-# clojure.math.numeric-tower
Formerly clojure.contrib.math
Math functions that deal intelligently with the various
types in Clojure's numeric tower, as well as math functions
commonly found in Scheme implementations.
-## Usage
-expt - (expt x y) is x to the yth power, returns an exact number
- if the base is an exact number, and the power is an integer,
- otherwise returns a double.
+Releases and Dependency Information
-abs - (abs n) is the absolute value of n
+Latest stable release: 0.0.1
-gcd - (gcd m n) returns the greatest common divisor of m and n
+* [All Released Versions](
-lcm - (lcm m n) returns the least common multiple of m and n
+* [Development Snapshot Versions](;gav~org.clojure~math.numeric-tower~~~)
-When floor, ceil, and round are passed doubles, we just defer to
-the corresponding functions in Java's Math library. Java's
-behavior is somewhat strange (floor and ceil return doubles rather
-than integers, and round on large doubles yields spurious results)
-but it seems best to match Java's semantics. On exact numbers
-(ratios and decimals), we can have cleaner semantics.
+[Leiningen]( dependency information:
-floor - (floor n) returns the greatest integer less than or equal to n.
- If n is an exact number, floor returns an integer,
- otherwise a double.
+[org.clojure/math.numeric-tower "0.0.1"]
-ceil - (ceil n) returns the least integer greater than or equal to n.
- If n is an exact number, ceil returns an integer,
- otherwise a double.
+[Maven]( dependency information:
-round - (round n) rounds to the nearest integer.
- round always returns an integer. round rounds up for values
- exactly in between two integers.
+ <groupId>org.clojure</groupId>
+ <artifactId>math.numeric-tower</artifactId>
+ <version>0.0.1</version>
+Example Usage
-sqrt - Implements the sqrt behavior I'm accustomed to from PLT Scheme,
- specifically, if the input is an exact number, and is a square
- of an exact number, the output will be exact. The downside
- is that for the common case (inexact square root), some extra
- computation is done to look for an exact square root first.
- So if you need blazingly fast square root performance, and you
- know you're just going to need a double result, you're better
- off calling java's Math/sqrt, or alternatively, you could just
- convert your input to a double before calling this sqrt function.
- If Clojure ever gets complex numbers, then this function will
- need to be updated (so negative inputs yield complex outputs).
+(ns example.core
+ (:require [clojure.math.numeric-tower :as math]))
-exact-integer-sqrt - Implements a math function from the R6RS Scheme
- standard. (exact-integer-sqrt k) where k is a non-negative integer,
- returns [s r] where k = s^2+r and k < (s+1)^2. In other words, it
- returns the floor of the square root and the "remainder".
+(defn- sqr
+ "Uses the numeric tower expt to square a number"
+ [x]
+ (math/expt x 2))
-## License
+(defn euclidean-squared-distance
+ "Computes the Euclidean squared distance between two sequences"
+ [a b]
+ (reduce + (map (comp sqr -) a b)))
+(defn euclidean-distance
+ "Computes the Euclidean distance between two sequences"
+ [a b]
+ (math/sqrt (euclidean-squared-distance a b)))
+(let [a [1 2 3 5 8 13 21]
+ b [0 2 4 6 8 10 12]
+ (euclidean-distance a b))
+;;=> 9.643650760992955
+Refer to docstrings in the `clojure.math.numeric-tower` namespace for
+additional documentation.
+[API Documentation](
+Developer Information
+* [GitHub project](
+* [Bug Tracker](
+* [Continuous Integration](
+* [Compatibility Test Matrix](
+* Release 0.0.1 on 2011-10-15
+ * Initial release.
+ * Source-compatible with clojure.contrib.math, except for the name change.
Distributed under the Eclipse Public License, the same as Clojure.

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