Java atan atan(int f)

Description

atan

License

Apache License

Declaration

public static int atan(int f) 

Method Source Code

//package com.java2s;
/**/*  w ww.  j av a2  s  . c o  m*/
 * Copyright 2008 - 2012
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 * 
 * @project loon
 * @author cping
 * @email?javachenpeng@yahoo.com
 * @version 0.3.3
 */

public class Main {
    public static int atan(int f) {
        int sqr = mul(f, f);
        int result = 1365;
        result = mul(result, sqr);
        result -= 5579;
        result = mul(result, sqr);
        result += 11805;
        result = mul(result, sqr);
        result -= 21646;
        result = mul(result, sqr);
        result += 65527;
        result = mul(result, f);
        return result;
    }

    static public final float atan(float value) {
        return (float) Math.atan(value);
    }

    public static int mul(int x, int y) {
        long z = (long) x * (long) y;
        return ((int) (z >> 16));
    }
}

Related

1. atan(double arg)
2. atan(double x)
3. atan(float tan_value)
4. atan(float value)
5. atan(float x)
6. atan(Integer a)
7. atan(Number x)
8. atan_66s(double x)
9. atan_mag1(double x)