java 计算自定义底数的对数

To calculate a logarithm with custom base in Java, we use the following identity:

 

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@Test public void givenCustomLog_shouldReturnValidResults() {     assertEquals(customLog(2, 256), 8);     assertEquals(customLog(10, 100), 2); }   private static double customLog(double base, double logNumber) {     return Math.log(logNumber) / Math.log(base); }