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https://issues.apache.org/jira/browse/MATH-1652?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
nimo mayr updated MATH-1652:
----------------------------
Description:
The class {color:#d8d8d8}
{color}
{code:java}
org.apache.commons.math3.util.CombinatoricsUtils{code}
within the method
{code:java}
public static long binomialCoefficient(final int n, final int k){code}
contains the following comments:
{code:java}
// We use the formula
// (n choose k) = n! / (n-k)! / k!
// (n choose k) == ((n-k+1)...*n) / (1...*k)
// which could be written
// (n choose k) == (n-1 choose k-1) * n / k
{code}
I think, the second line
{code:java}
"(n choose k) = n! / (n-k)! / k!" {code}
must be written to
{code:java}
"(n choose k) = n! / (n-k)! * k!"{code}
was:
The class
{color:#d8d8d8} org.apache.commons.math3.util.CombinatoricsUtils{color}
within the method
{color:#8dcbe2}public{color}{color:#d8d8d8}
{color}{color:#8dcbe2}static{color}{color:#d8d8d8}
{color}{color:#8dcbe2}long{color}{color:#d8d8d8}
{color}{color:#bed6ff}binomialCoefficient{color}{color:#d8d8d8}({color}{color:#8dcbe2}final{color}{color:#d8d8d8}
{color}{color:#8dcbe2}int{color}{color:#d8d8d8}
{color}{color:#79abff}n{color}{color:#d8d8d8},
{color}{color:#8dcbe2}final{color}{color:#d8d8d8}
{color}{color:#8dcbe2}int{color}{color:#d8d8d8}
{color}{color:#79abff}k{color}{color:#d8d8d8}){color}
contains the following comments:
{color:#c7dd0c}// We use the formula{color}
{color:#d8d8d8} {color}{color:#c7dd0c}// (n choose k) = n! / (n-k)! / k!{color}
// (n choose k) == ((n-k+1){*}...*n) / (1{*}...*k)
{color:#d8d8d8} {color}{color:#c7dd0c}// which could be written{color}
{color:#d8d8d8} {color}{color:#c7dd0c}// (n choose k) == (n-1 choose k-1) * n /
k{color}
I think, the second line
{color:#172b4d}"(n choose k) = n! / (n-k)! / k!" {color}
must be written to
{color:#c7dd0c}"{color}(n choose k) = n! / (n-k)! * k!{color:#172b4d}"{color}.
> comments about the formula of binomialCoefficient wrong
> -------------------------------------------------------
>
> Key: MATH-1652
> URL: https://issues.apache.org/jira/browse/MATH-1652
> Project: Commons Math
> Issue Type: Improvement
> Reporter: nimo mayr
> Priority: Minor
>
> The class {color:#d8d8d8}
> {color}
> {code:java}
> org.apache.commons.math3.util.CombinatoricsUtils{code}
> within the method
> {code:java}
> public static long binomialCoefficient(final int n, final int k){code}
> contains the following comments:
> {code:java}
> // We use the formula
> // (n choose k) = n! / (n-k)! / k!
> // (n choose k) == ((n-k+1)...*n) / (1...*k)
> // which could be written
> // (n choose k) == (n-1 choose k-1) * n / k
> {code}
> I think, the second line
> {code:java}
> "(n choose k) = n! / (n-k)! / k!" {code}
> must be written to
> {code:java}
> "(n choose k) = n! / (n-k)! * k!"{code}
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