d3r6.txt

VB常用数值算法集 内含有解线性代数方程组

Public CHOOSE As String
Private Sub Command1_Click()
    'PROGRAM D3R6
    'Driver for routine QROMO
    X1 = 0#
    X2 = 1.5707963
    X3 = 3.1415926
    AINF = 1E+20
    Print
    Print Tab(5); "Improper integrals:"
    Print
    CHOOSE = "FUNCL"
    Call QROMO(X1, X2, RESULT, "MIDSQL")
    Print Tab(5); "Function: SQR(x)/SIN(x)      Interval: (0,PI/2)"
    Print Tab(5); "Using: MIDSQL                Result: ";
    Print Format$(RESULT, "0.####")
    Print
    CHOOSE = "FUNCU"
    Call QROMO(X2, X3, RESULT, "MIDSQU")
    Print Tab(5); "Function: SQR(PI-x)/SIN(x)   Interval: (PI/2,PI)"
    Print Tab(5); "Using: MIDSQU                Result: ";
    Print Format$(RESULT, "0.####")
    Print
    CHOOSE = "FUNCINF"
    Call QROMO(X2, AINF, RESULT, "MIDINF")
    Print Tab(5); "Function: SIN(x)/x^2        Interval: (PI/2,infty)"
    Print Tab(5); "Using: MIDINF                Result: ";
    Print Format$(RESULT, "0.####")
    Print
    CHOOSE = "FUNCINF"
    Call QROMO(-AINF, -X2, RESULT, "MIDINF")
    Print Tab(5); "Function: SIN(x)/x^2        Interval: (-infty,-PI/2)"
    Print Tab(5); "Using: MIDINF                Result: ";
    Print Format$(RESULT, "0.####")
    Print
    CHOOSE = "FUNCEND"
    Call QROMO(X1, X2, RES1, "MIDSQL")
    Call QROMO(X2, AINF, RES2, "MIDINF")
    Print Tab(5); "Function: EXP(-x)/SQR(x)     Interval: (0,infty)"
    Print Tab(5); "Using: MIDSQL,MIDINF         Result: ";
    Print Format$(RES1 + RES2, "0.####")
End Sub
Function FUNC(X)
    'Dim CHOOSE As String
    If CHOOSE = "FUNCL" Then FUNC = FUNCL(X)
    If CHOOSE = "FUNCU" Then FUNC = FUNCU(X)
    If CHOOSE = "FUNCINF" Then FUNC = FUNCINF(X)
    If CHOOSE = "FUNCEND" Then FUNC = FUNCEND(X)
End Function
Function FUNCL(X)
    FUNCL = Sqr(X) / Sin(X)
End Function
Function FUNCU(X)
    PI = 3.1415926
    FUNCU = Sqr(PI - X) / Sin(X)
End Function
Function FUNCINF(X)
    FUNCINF = Sin(X) / (X ^ 2)
End Function
Function FUNCEND(X)
    FUNCEND = Exp(-X) / Sqr(X)
End Function