请问，这段绘制动态函数曲线的程序错在那里？请帮助改正

liyanchao1 发表于 2004-2-25 08:56:00

请问各位高手，我用VBA编了一段利用多段线绘制从固定点（x1,y1,z1) 到当前鼠标位置的动态函数曲线------y=k*(x-x1)^2+y1 的程序，可是却无法执行，请问错在那里？多谢指教！

****************************

Sub pl() Dim p1(0 To 2) As Double Dim p2 As Variant Dim pntobj As Variant

Dim lobj As AcadLWPolyline Dim vers(0 To 2000) As Double

Dim k As Double Dim g As Double Dim b As Double

Dim x1 As Double Dim y1 As Double Dim x As Double Dim y As Double Dim i As Double Dim a As Double

Dim l As Double Dim m As Double Dim n As Double

g = 32.7718 / 1000 b = 68.5036 k = g / (2 * b)

 l = 100 m = 100 n = 0 p1(0) = l p1(1) = m p1(2) = n

p2 = ThisDrawing.Utility.GetPoint(, "p2") x1 = (p2(1) - m + k * l ^ 2 - k * p2(0) ^ 2) / (2 * k(l - p2(0))) y1 = m - k * (l - x1) ^ 2

vers(0) = l vers(1) = m

 i = l a = 2

If i <= p(0) Then While i <= p2(0) x = p1(0) + i y = k * ((x - x1) * 10) ^ 2 + y1 i = i + 0.5 vers(a) = x vers(a + 1) = y a = a + 2 Wend Else x = p1(0) + i y = k * ((x - x1) * 10) ^ 2 + y1 i = i - 0.5 vers(a) = x vers(a + 1) = y a = a + 2 Wend vers(a) = p2(0) vers(a + 1) = p2(1) Set lobj = ThisDrawing.ModelSpace.AddLightWeightPolyline(vers)

End Sub

*************************

topirol 发表于 2004-2-25 09:04:00

1、x1 = (p2(1) - m + k * l ^ 2 - k * p2(0) ^ 2) / (2 * k(l - p2(0)))是不是改成

x1 = (p2(1) - m + k * l ^ 2 - k * p2(0) ^ 2) / (2 * k*(l - p2(0)))

2、If i <= p(0) Then

是什么意思？p(0)是什么？

liyanchao1 发表于 2004-2-25 09:21:00

对不起，刚才传输错误。“If i <= p(0) then ”应为 “ if i<= p1(0) then ”，我进行调试时，总是提示“编译错误：缺少数组”。请大侠多多指教！不胜感谢！

topirol 发表于 2004-2-25 12:04:00

"缺少数组"是

x1 = (p2(1) - m + k * l ^ 2 - k * p2(0) ^ 2) / (2 * k(l - p2(0)))的原因

改成

x1 = (p2(1) - m + k * l ^ 2 - k * p2(0) ^ 2) / (2 * k * (l - p2(0)))

后面还有很多问题，不知道你的意图是什么

liyanchao1 发表于 2004-2-25 14:27:00

大侠，我把上述问题该了以后，程序执行后还是没有任何显示。请帮助修改下列程序，或者帮助重新编写一段程序。多多有劳！

Sub pl() '绘制抛物线：y=k*(x-x1)^2+y1' Dim p1(0 To 2) As Double Dim p2 As Variant Dim pntobj As Variant

Dim lobj As AcadLWPolyline Dim vers(0 To 2000) As Double

Dim k As Double Dim g As Double Dim b As Double

Dim x1 As Double Dim y1 As Double Dim x As Double Dim y As Double Dim i As Double Dim a As Double

Dim l As Double Dim m As Double Dim n As Double Dim O As Double Dim P As Double Dim Q As Double

'确定函数曲线的参数K的值

g = 32.7718 / 1000 b = 68.5036 k = g / (2 * b)

'确定函数曲线的第一点的坐标 l = 100 m = 100 n = 0 p1(0) = l p1(1) = m p1(2) = n

'提取当前鼠标的动态坐标 p2 = ThisDrawing.Utility.GetPoint(, "p2") O = p2(0) P = p2(1) Q = p2(2)

'计算曲线函数参数X1、Y1的值 x1 = (P - m + k * l ^ 2 - k * O ^ 2) / (2 * k * (l - O)) y1 = m - k * (l - x1) ^ 2

'确定函数曲线的第一点 vers(0) = l vers(1) = m

i = l a = 2

'利用循环确定函数曲线上的端点之间的若干坐标值 If i <= p1(0) Then While i <= p1(0) x = p1(0) + i y = k * ((x - x1) * 10) ^ 2 + y1 i = i + 0.5 vers(a) = x vers(a + 1) = y a = a + 2 Wend Else While i > p1(0) x = p1(0) - i y = k * ((x - x1) * 10) ^ 2 + y1 i = i - 0.5 vers(a) = x vers(a + 1) = y a = a + 2 Wend End If

'确定函数曲线的最后一点 vers(a) = p2(0) vers(a + 1) = p2(1)

'利用多义线绘制动态函数曲线 Set lobj = ThisDrawing.ModelSpace.AddLightWeightPolyline(vers)

End Sub

topirol 发表于 2004-2-25 16:42:00

是不是在两点中间画抛物线呢？在（中间插几个点呢？或者是由间隔距离来控制？）

liyanchao1 发表于 2004-2-25 18:26:00

在一个已知的固定点、和当前的活动鼠标所在的动态点之间画抛物线，中间点的选取由间隔距离来控制！请问大侠该如何编程？

ahlzl 发表于 2004-2-25 22:12:00

liyanchao1发表于2004-2-25 18:26:00static/image/common/back.gif在一个已知的固定点、和当前的活动鼠标所在的动态点之间画抛物线，中间点的选取由间隔距离来控制！请问大侠该如何编程？

 抛物线的编程不难,关键是你表达不清楚!过两点是不能确定唯一的抛物线的,"中间点的选取由间隔距离来控制！"是什么意思?!

liyanchao1 发表于 2004-2-26 08:56:00

在要绘制的抛物线: y=k*(x-x1)^2+y1 中，已知曲线上的一个固定点的坐标、和参数k的值，要绘制一条同时通过当前活动鼠标的动态坐标点的动态抛物线。中间的点的坐标的选取由循环语句控制：按x坐标每增加或减少i值进行取点。关键是如何获得活动鼠标的动态坐标值；请问各位大侠，下面这段程序能否获得鼠标的动态坐标值，使得绘制的抛物线随着鼠标的移动而动态变化？那位大侠能否帮助编一个获得活动鼠标的动态坐标值的程序？

'提取当前鼠标的动态坐标 p2 = ThisDrawing.Utility.GetPoint(, "p2") O = p2(0) P = p2(1) Q = p2(2)

topirol 发表于 2004-2-26 12:19:00

跟“橡皮条”一样吗？以前有人讨论过，但不知道有没有结果，好像很复杂的……

页: [1] 2

明经CAD社区's Archiver

请问，这段绘制动态函数曲线的程序错在那里？请帮助改正