arcsin(x) added

2023-01-26 01:45:38 +08:00
parent 05869ac0ae
commit f75fcacc0d
36 changed files with 212 additions and 12 deletions
@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace StgSharp
+{
+
+    //对4字节空间的联合体的C#实现
+    [StructLayout(LayoutKind.Explicit, Size = 4)]
+    public struct Union4
+    {
+        [FieldOffset(0)]
+        public byte b0;
+        [FieldOffset(1)]
+        public byte b1;
+        [FieldOffset(2)]
+        public byte b2;
+        [FieldOffset(3)]
+        public byte b3;
+        //得到对应的int值
+        [FieldOffset(0)]
+        public uint i;
+        //得到对应的float值
+        [FieldOffset(0)]
+        public float f;
+
+
+        public Union4(float x, uint y)
+        {
+            b0 = 0;
+            b1 = 0;
+            b2 = 0;
+            b3 = 0;
+            i = 0;
+            f = x;
+            y = i;
+        }
+    }
+
+
+    
+}
@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace StgSharp
+{
+    //对8字节空间的联合体的C#实现
+    [StructLayout(LayoutKind.Explicit, Size = 8)]
+    public struct Union8
+    {
+        [FieldOffset(0)]
+        public byte b0;
+        [FieldOffset(1)]
+        public byte b1;
+        [FieldOffset(2)]
+        public byte b2;
+        [FieldOffset(3)]
+        public byte b3;
+        //得到对应的int值
+        [FieldOffset(0)]
+        public int i1;
+        [FieldOffset(4)]
+        public int i2;
+        //得到对应的float值
+        [FieldOffset(0)]
+        public double f;
+    }
+}
@@ -0,0 +1,92 @@
+
+// some of the code is rewritten from the AMD code:
+// https://github.com/amd/aocl-libm-ose/blob/a43e092b03213eb0e129a1cc129900e6e4475778/src/ref/asinf.c
+
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace StgSharp
+{
+    public static unsafe partial class Math
+    {
+
+        const float
+        piby2_tail = 7.5497894159e-08f, /* 0x33a22168 */
+        hpiby2_head = 7.8539812565e-01f, /* 0x3f490fda */
+        piby2 = 1.5707963705e+00f; /* 0x3fc90fdb */
+
+
+        /// <summary>
+        /// Reurns the value of ArcSin(x)
+        /// </summary>
+        /// <param name="x"></param>
+        /// <returns></returns>
+        /// <exception cref="ArgumentException"></exception>
+        public static float ASin(float x )
+        {
+            
+            int sign = 1;
+            float y ;
+
+            if (x<0)
+            {
+                sign = -1;
+                y = -x;
+            }
+            else
+            {
+                y = x;
+            }
+
+            if ( x>1)
+            {
+                throw new ArgumentException();
+            }
+
+            float r, s, u, v = 0.0f;
+            bool transform = (y >= 0.5f);
+            
+            if (transform)
+            {
+                r = 0.5f * (1.0f - y);
+                s = StgSharp.Math.Sqrt(r);
+                y = s;
+            }
+            else
+            {
+                r = y * y;
+            }
+            u= r * (0.184161606965100694821398249421F +
+                   (-0.0565298683201845211985026327361F +
+                   (-0.0133819288943925804214011424456F -
+                   0.00396137437848476485201154797087F * r) * r) * r) /
+                  (1.10496961524520294485512696706F -
+                   0.836411276854206731913362287293F * r);
+            /**/
+
+            if (transform)
+            {
+                float c, s1, p, q;
+                uint us;
+
+                us = *(uint*)&s;
+                uint uss = us & 0xffff0000;
+                s1 = *(float*)&uss;
+
+                c = (r - s1 * s1) / (s + s1);
+                p = 2.0F * s * u - (piby2_tail - 2.0F * c);
+                q = hpiby2_head - 2.0F * s1;
+                v = hpiby2_head - (p - q);
+            }
+            else
+            {
+                v = y + y * u;
+            }/**/
+
+            return sign * v * 90 / piby2;
+
+        }
+    }
+}
@@ -0,0 +1,10 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace StgSharp
+{
+    public static unsafe partial class Math
+    {
+    }
+}
@@ -8,7 +8,6 @@ namespace StgSharp
    public static partial class Math
    {
        /*本方法将小数部分统一提升至2^16处后进行线性近似
-         
        const uint sqmov = 0b_0100_0111_1000_0000_0000_0000_0000_0000;
        const float sqmov1 = 0.0015947f;
        const float sqmov2 = 156.7673435f;
@@ -4,6 +4,14 @@
        <name>StgSharp</name>
    </assembly>
    <members>
+        <member name="M:StgSharp.Math.ASin(System.Single)">
+            <summary>
+            Reurns the value of ArcSin(x)
+            </summary>
+            <param name="x"></param>
+            <returns></returns>
+            <exception cref="T:System.ArgumentException"></exception>
+        </member>
        <member name="M:StgSharp.Math.Log(System.Single)">
            <summary>
            
@@ -1 +1 @@
-db0ba6dd25ed071a0f5414145ab29a83438c6530
+b7317d4b12ba4162c78ad3d204d71202d31826dd
@@ -4,6 +4,14 @@
        <name>StgSharp</name>
    </assembly>
    <members>
+        <member name="M:StgSharp.Math.ASin(System.Single)">
+            <summary>
+            Reurns the value of ArcSin(x)
+            </summary>
+            <param name="x"></param>
+            <returns></returns>
+            <exception cref="T:System.ArgumentException"></exception>
+        </member>
        <member name="M:StgSharp.Math.Log(System.Single)">
            <summary>
            
@@ -11,21 +11,21 @@ internal class Program
        Console.WriteLine(cc/2);
        /**/

-        
        /*
-        Console.WriteLine(StgSharp.Math.Sin(1.06f));
+        float test = StgSharp.Math.ASin(StgSharp.Math.Sqrt(3.0f) / 2);
+        Console.WriteLine(test);
        /**/

        /*
        for (int wasd = 0; wasd < 100; wasd++)
        {
            float time = 1000000;
-            double a = 114514;
+            float a = 114514;
            System.Diagnostics.Stopwatch stopwatch = new Stopwatch();
            stopwatch.Start(); //  开始监视代码运行时间
            for (float i = 2; i < time; i++)
            {
-                a = StgSharp.Math.Tan(i);
+                a = StgSharp.Math.ASin(i/(time/2)-1);
            }
            stopwatch.Stop(); //  停止监视
            TimeSpan timespan = stopwatch.Elapsed; //  获取当前实例测量得出的总时间
@@ -37,9 +37,9 @@ internal class Program
            double b = 114514;
            double time2 = time;
            stopwatch1.Start();
-            for (double i = 2; i < time2; i++)
+            for (float i = 2; i < time2; i++)
            {
-                b = System.Math.Tan(i);
+                b = System.MathF.Asin(i / (time / 2) - 1);
            }
            stopwatch1.Stop();
            timespan = stopwatch1.Elapsed;
@@ -49,12 +49,13 @@ internal class Program
        }
        /**/

-        
+        /*
        double accuracy = 0;
-        for (float i = 1f; i < 4000000; i += 1f)
+        for (float i = -1f; i < 1f; i += 0.000001f)
        {
-            double r1 = StgSharp.Math.Sin(i);
-            double r2 = System.Math.Sin(i *  ( 2 * System.Math.PI) / 360);
+            
+            double r1 = StgSharp.Math.ASin(i);
+            double r2 = System.Math.Asin(i)*180/3.1415926;
            double ac = ( System.Math.Max(r1,r2)- System.Math.Min(r1, r2) ) / r2;
            if (ac>accuracy)
            {
@@ -4,6 +4,14 @@
        <name>StgSharp</name>
    </assembly>
    <members>
+        <member name="M:StgSharp.Math.ASin(System.Single)">
+            <summary>
+            Reurns the value of ArcSin(x)
+            </summary>
+            <param name="x"></param>
+            <returns></returns>
+            <exception cref="T:System.ArgumentException"></exception>
+        </member>
        <member name="M:StgSharp.Math.Log(System.Single)">
            <summary>