运行时错误5？

Question

我想定义一个求解微分方程系统的微分函数，但是当我运行调用这个子例程的实际宏时，我不断收到运行时错误5：无效的过程调用或参数。当x不大于1时，If语句中会发生此错误，Qv将使用所提供的公式进行计算。在进入调试阶段时，所有变量都有值，但它给了我错误，我不知道为什么。有人可以帮忙吗？

Sub Derivs(x As Double, y() As Double, dydx() As Double) 

Const g As Double = 32.1740485564 
Const Hr As Double = 100 
Const h0 As Double = 80 
Const fm As Double = 0.024 
Const L As Double = 1500 
Const dp As Double = 2 
Const tc As Double = 5 
Const k As Double = 25.7 
Const Di As Double = 5 

Dim u0 As Double 
Dim Qv As Double 
Dim Qv0 As Double 
Dim hstar As Double 

u0 = ((g * h0/((1/2) * fm * (L/dp))) * ((Hr/h0) - 1))^(1/2) 

Qv0 = (u0 * 3.14 * Di^2)/4 

hstar = h0 - (Qv0/k)^2 

If x >= 1 Then 
    Qv = 0 
Else 
    Qv = k * (h0^0.5) * (1 - x) * (y(1) - hstar/h0)^0.5 
End If 

dydx(0) = ((tc * g * h0)/(L * u0)) * (((Hr/h0) - y(1)) - ((Hr/h0) - 1) * y(0) * Abs(y(0))) 

dydx(1) = ((dp/Di)^2) * (u0 * tc/h0) * y(0) - ((4 * Qv * tc)/(3.14 * h0 * Di^2)) 

End Sub 

那么调用此子程序的宏：

Sub RungeKutta() 

Dim y(1) As Double 
Dim dydx(1) As Double 
Dim yout(1) As Double 
Dim yerr(1) As Double 
Dim x As Double 
Dim hdid As Double 
Dim yscal(1) As Double 
Dim hnext As Double 
Dim ystart(1) As Double 
Dim NOk As Integer 
Dim NBad As Integer 
Dim h As Double 

Const n As Integer = 2 
Dim htry As Double 
Const eps As Double = 0.00000001 
Dim x1 As Double 
Dim x2 As Double 
Const nvar As Integer = 2 
Dim h1 As Double 
Const hmin As Double = 0.001 

h = 0.001 
x1 = 0 
x2 = 10 
h1 = 0.01 
x = x1 
h = Sgn(x2 - x1) * Abs(h1) 
NOk = 0 
NBad = 0 
kount = -1 

x = 0 

y(0) = 1# 
y(1) = 1# 

Call Derivs(x, y(), dydx()) 

Call odeint(ystart(), nvar, x1, x2, eps, h1, hmin, NOk, NBad) 

' I have a bunch of coding to input the calculations into a spreadsheet that I am omitting 

End Sub 

宏主程序：

Sub odeint(ystart() As Double, nvar As Integer, x1 As Double, x2 As Double, eps As Double, h1 As Double, hmin As Double, NOk As Integer, NBad As Integer) 

Const MaxStp As Double = 10000 
Const Tiny As Double = 10^(-30) 

Dim y() As Double 
Dim yscal() As Double 
Dim dydx() As Double 
Dim x As Double 
Dim h As Double 
Dim hdid As Double 
Dim hnext As Double 
Const n As Integer = 2 

NM1 = n - 1 

nvar = 2 

ReDim y(NM1) 
ReDim dydx(NM1) 
ReDim yscal(NM1) 


x = x1 
h = Sgn(x2 - x1) * Abs(h1) 
NOk = 0 
NBad = 0 
kount = -1 

kmax = 500 

ReDim xp(kmax) 
ReDim yp(NM1, kmax) 

dxsav = (x2 - x1)/kmax 


For I = 0 To nvar - 1 
    y(I) = ystart(I) 

Next I 

If kmax > 0 Then xsav = x - 2 * dxsav 
    For nstp = 1 To MaxStp 
     Call Derivs(x, y(), dydx()) 

     For I = 0 To nvar - 1 
      yscal(I) = Abs(y(I)) + Abs(h * dydx(I)) + Tiny 
     Next I 

     If kmax > 0 Then 

      If Abs(x - xsav) > Abs(dxsav) Then 

       If kount < kmax - 1 Then 
        kount = kount + 1 
        xp(kount) = x 

        For I = 0 To nvar - 1 
         yp(I, kount) = y(I) 
        Next I 

        xsav = x 
       End If 
      End If 
     End If 
     If (x + h - x2) * (x + h - x1) > 0 Then h = x2 - x 
      Call rkqs(y(), dydx(), nvar, x, h, eps, yscal(), hdid, hnext) 
      If hdid = h Then 
       NOk = NOk + 1 
      Else 
       NBad = NBad + 1 
      End If 

      If (x - x2) * (x2 - x1) >= 0 Then 
       For I = 0 To nvar - 1 
        ystart(I) = y(I) 
       Next I 

       If Not kmax = 0 Then 
        kount = kount + 1 
        xp(kount) = x 

        For I = 0 To nvar - 1 
         yp(I, kount) = y(I) 
        Next I 
       End If 
       Exit Sub 
      End If 

      If Abs(hnext) < hmin Then MsgBox "Stepsize smaller than minimum in odeint!", vbExclamation 

      h = hnext 
    Next nstp 

MsgBox "Too many steps in odeint", vbExclamation 

End Sub 

调用该子程序：

Sub rkqs(y() As Double, dydx() As Double, n As Integer, x As Double, htry As Double, eps As Double, yscal() As Double, hdid As Double, hnext As Double) 

NM1 = n - 1 

Dim ytemp() As Double 
Dim yerr() As Double 
Dim h As Double 
Const Tiny As Double = 10^(-30) 

ReDim ytemp(NM1) 
ReDim yerr(NM1) 

Const Safety As Double = 0.9 
Const PGrow As Double = -0.2 
Const PShrink As Double = -0.25 
Const ErrCon As Double = (5#/Safety)^(1#/PGrow) 

h = htry 
Do 
    Call rkck(y(), dydx(), n, x, h, ytemp(), yerr()) 

    ErrMax = 0 

    For I = 0 To NM1 
      yscal(I) = Abs(y(I)) + Abs(h * dydx(I)) + Tiny 
     Next I 

    For I = 0 To n - 1 
     If Abs(yerr(I)/yscal(I)) > ErrMax Then ErrMax = Abs(yerr(I)/yscal(I)) 
    Next I 

    ErrMax = ErrMax/eps 

    If ErrMax > 1 Then 
     dummy = h 
     h = Safety * h * (ErrMax^PShrink) 

     If h < 0.1 * dummy Then 
      h = 0.1 * dummy 
     End If 

     xNew = x + h 

     If xNew = x Then MsgBox "Stepsize underflow in rkqsl", vbExclamation 
     ContLoop = True 

    Else 
     If ErrMax > ErrCon Then 
      hnext = Safety * h * (ErrMax^PGrow) 
     Else 
      hnext = 5 * h 
     End If 

     hdid = h 

     x = x + h 

     For I = 0 To n - 1 
      y(I) = ytemp(I) 
     Next I 

     ContLoop = False 
    End If 

Loop While ContLoop 

End Sub 

然后调用这个子程序ine：

Sub rkck(y() As Double, dydx() As Double, n As Integer, x As Double, h As Double, yout() As Double, yerr() As Double) 

Dim NM1 As Integer 
Dim I As Integer 
Dim ak2() As Double 
Dim ak3() As Double 
Dim ak4() As Double 
Dim ak5() As Double 
Dim ak6() As Double 
Dim ytemp() As Double 

NM1 = n - 1 

ReDim ak2(NM1) 
ReDim ak3(NM1) 
ReDim ak4(NM1) 
ReDim ak5(NM1) 
ReDim ak6(NM1) 
ReDim ytemp(NM1) 

Const A2 As Double = 1#/5# 
Const A3 As Double = 3#/10# 
Const A4 As Double = 3#/5# 
Const A5 As Double = 1# 
Const A6 As Double = 7#/8# 

Const B21 As Double = 1#/5# 
Const B31 As Double = 3#/40# 
Const B32 As Double = 9#/40# 
Const B41 As Double = 3#/10# 
Const B42 As Double = -9#/10# 
Const B43 As Double = 6#/5# 
Const B51 As Double = -11#/54# 
Const B52 As Double = 5#/2# 
Const B53 As Double = -70#/27# 
Const B54 As Double = 35#/27# 
Const B61 As Double = 1631#/55296# 
Const B62 As Double = 175#/512# 
Const B63 As Double = 575#/13824# 
Const B64 As Double = 44275#/110592# 
Const B65 As Double = 253#/4096# 

Const C1 As Double = 37#/378# 
Const C3 As Double = 250#/621# 
Const C4 As Double = 125#/594# 
Const C6 As Double = 512#/1771# 

Const DC1 As Double = C1 - 2825#/27648# 
Const DC3 As Double = C3 - 18575#/48384# 
Const DC4 As Double = C4 - 13525#/55296# 
Const DC5 As Double = -277#/14336# 
Const DC6 As Double = C6 - 1#/4# 

'First Step 
For I = 0 To n - 1 
    ytemp(I) = y(I) + B21 * h * dydx(I) 
Next I 

'Second Step 
Call Derivs(x + A2 * h, ytemp(), ak2()) 

For I = 0 To n - 1 
    ytemp(I) = y(I) + h * (B31 * dydx(I) + B32 * ak2(I)) 
Next I 

'Third Step 
Call Derivs(x + A3 * h, ytemp(), ak3()) 

For I = 0 To n - 1 
    ytemp(I) = y(I) + h * (B41 * dydx(I) + B42 * ak2(I) + B43 * ak3(I)) 
Next I 

'Fourth Step 
Call Derivs(x + A4 * h, ytemp(), ak4()) 

For I = 0 To n - 1 
    ytemp(I) = y(I) + h * (B51 * dydx(I) + B52 * ak2(I) + B53 * ak3(I) + B54 * ak4(I)) 
Next I 

'Fifth Step 
Call Derivs(x + A5 * h, ytemp(), ak5()) 

For I = 0 To n - 1 
    ytemp(I) = y(I) + h * (B61 * dydx(I) + B62 * ak2(I) + B63 * ak3(I) + B64 * ak4(I) + B65 * ak5(I)) 
Next I 

'Sixth Step 
Call Derivs(x + A6 * h, ytemp(), ak6()) 

For I = 0 To n - 1 
    yout(I) = y(I) + h * (C1 * dydx(I) + C3 * k3(I) + C4 * ak4(I) + C6 * ak6(I)) 
Next I 

For I = 0 To n - 1 
    yerr(I) = h * (DC1 * dydx(I) + DC3 * ak3(I) + DC4 * ak4(I) + DC5 * ak5(I) + DC6 * ak6(I)) 
Next I 

End Sub 

这是Runge Kutta方法。

所以我调试每三个方案的分别与RKCK开始，然后进入RKQS，然后通过本质上写入测试宏每个，包括所有的参数，以ODEINT，输出在消息框中与各个节目搭话的计算值，并要求下面的示例中的方程组：

Sub Derivs1(x As Double, y() As Double, dydx() As Double) 


dydx(0) = -2 * x * y(0) 

dydx(1) = -3 * y(1) * x^2 

End Sub 

每个程序完美工作的这个例子，所以我决定测试与实际问题陈述式中，各测试宏。 RKCK工作得很好，RKQS也是如此。然后当我到达ODEINT时，弹出错误消息。

Answer 1

运行时错误5是“无效的过程调用”错误。

我看不到那怎么行可能会产生错误，只要Y数组中的索引1

你需要给调用类似于其运行没有任何下面这个函数的例子值错误。

Sub test() 
Dim dydx(0 To 1) As Double 
Dim y(0 To 1) As Double 
dydx(0) = 1 
dydx(1) = 2 
y(0) = 1 
y(1) = 2 
Derivs 0.5, y, dydx 

End Sub 

我碰到你编辑的代码，并当

Qv = k * (h0^0.5) * (1 - x) * (y(1) - hstar/h0)^0.5 

发生错误您的变量值：

y(1) = 0 
hstar = 38.3 
h0 = 80 

这意味着：

(y(1) - hstar/h0) = -0.478857734838603 

由于让 - 弗朗索瓦科贝特提到，方皮vve不支持-ve数的重新根目录，并导致运行时错误5.

Answer 2

您可能正在取一个负数的平方根。

x^0.5会给你一个“无效的过程调用或参数”错误时x为负。

尝试在调试模式下逐句通过您的代码以确认此操作。