d4r12.frm

来自「常用数值算法集哈」· FRM 代码 · 共 59 行

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   2670
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   3600
   LinkTopic       =   "Form1"
   ScaleHeight     =   2670
   ScaleWidth      =   3600
   StartUpPosition =   3  'Windows Default
   Begin VB.CommandButton Command1 
      Caption         =   "Command1"
      Height          =   375
      Left            =   1920
      TabIndex        =   0
      Top             =   2040
      Width           =   1335
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub Command1_Click()
    'PROGRAM D4R12
    'Driver for routine ERFCC
    Dim ACTUAL(5), X(5)
    ACTUAL(1) = 0.7772974
    ACTUAL(2) = 0.257899
    ACTUAL(3) = 0.1572992
    ACTUAL(4) = 0.089686
    ACTUAL(5) = 0.0109095
    X(1) = 0.2
    X(2) = 0.8
    X(3) = 1#
    X(4) = 1.2
    X(5) = 1.8
    Print
    Print "     X      Actual      ERFCC(X)"
    For I = 1 To 5
        Print Tab(4); Format$(X(I), "#0.0#");
        Print Tab(12); Format$(ACTUAL(I), "0.0000000");
        Print Tab(25); Format$(ERFCC(X(I)), "0.0000000")
    Next I
End Sub
Function ERFCC(X)
    Z = Abs(X)
    T = 1# / (1# + 0.5 * Z)
    DDD = -0.82215223 + T * 0.17087277
    AAA = T * (-1.13520398 + T * (1.48851587 + T * DDD))
    BBB = T * (-0.18628806 + T * (0.27886807 + AAA))
    CCC = T * (0.37409196 + T * (0.09678418 + BBB))
    ERFCC = T * Exp(-Z * Z - 1.26551223 + T * (1.00002368 + CCC))
    If X < 0# Then ERFCC = 2# - ERFCC
End Function