用Cad畫(huà)二次拋物線(共4頁(yè))

1、精選優(yōu)質(zhì)文檔-傾情為你奉上Cad畫(huà)二次拋物線如y=ax2+bx+c 第一步 確認(rèn)cad中有VBA module如果沒(méi)有請(qǐng)下載，即CAD中“工具”“宏”“visual basic編輯器”，點(diǎn)thisdrawing第二步 打開(kāi)cadalt+F11打開(kāi)VBA窗口添加模塊復(fù)制以下 Sub pwx() '定義幾個(gè)點(diǎn) Dim pntO(2) As Double Dim pntA(2) As Double Dim pntB(2) As Double Dim pntC(2) As Double Dim pntD(2) As DoubleDim pntE(2) As Double '設(shè)拋物線方程

2、為:y=ax²+bx+c Dim a As Double Dim b As Double Dim c As Double '設(shè)拋物線的寬度為l Dim l As Double Dim p As Double Dim Co As Acad3DSolid Dim Se AsAcadRegion Dim Pa As Acad3DFace Dim PntAsAcadPoint Dim Sp() As AcadObject a = InputBox("請(qǐng)輸入y=a*x*x+b*x+c中對(duì)應(yīng)的a:", "拋物線方程參數(shù)") If a = 0 The

3、n MsgBox "a=0, 不是拋物線": End b = InputBox("請(qǐng)輸入y=a*x*x+b*x+c中對(duì)應(yīng)的b:", "拋物線方程參數(shù)") c = InputBox("請(qǐng)輸入y=a*x*x+b*x+c中對(duì)應(yīng)的c:", "拋物線方程參數(shù)") l = InputBox("請(qǐng)輸入所要畫(huà)的拋物線寬度l:", "拋物線寬度") l = l / 2 '計(jì)算x²=2py中的p p = 1 / Abs(a) '定義O點(diǎn) pntO(0

4、) = 0 pntO(1) = 0 pntO(2) = 0 '定義A點(diǎn) pntA(0) = 0 pntA(1) = 0 pntA(2) = l * Sqr(3) / 2 '畫(huà)圓錐 Set Co = ThisDrawing.ModelSpace.AddCone(pntO, l, l * Sqr(3) '移動(dòng)圓錐,使底部圓在xy平面上 Co.MovepntO, pntA If l > p / 2 Then '定義A點(diǎn) pntA(0) = 0 pntA(1) = p / 2 pntA(2) = (l - p / 2) * Sqr(3) '定義B點(diǎn) pnt

5、B(0) = 0 pntB(1) = -l + p pntB(2) = 0 '定義C點(diǎn) pntC(0) = 1 pntC(1) = -l + p pntC(2) = 0 '畫(huà)剝面線 Set Se = Co.SectionSolid(pntA, pntB, pntC) '剝面線旋轉(zhuǎn)到xy平面 Se.Rotate3D pntB, pntC, -60 * 4 * Atn(1) / 180'定義D點(diǎn) pntD(0) = 0 pntD(1) = -l pntD(2) = 0 '定義E點(diǎn) pntE(0) = 1 pntE(1) = 0 pntE(2) = 0 

6、9;移動(dòng)剝面線,使頂點(diǎn)在(0,0,0)位置 Se.MovepntO, pntD '當(dāng)a>0時(shí),翻轉(zhuǎn)曲線 If a > 0 Then Se.Rotate3D pntO, pntE, 180 * 4 * Atn(1) / 180 '重新設(shè)E點(diǎn) pntE(0) = -b / (2 * a) pntE(1) = (4 * a * c - b 2) / (4 * a) pntE(2) = 0 '移拋物線 Se.MovepntO, pntE '炸開(kāi)剝面線 Sp = Se.Explode '刪除輔助內(nèi)容 Co.Delete Se.Delete Sp(1).

7、Delete Else MsgBox "輸入的l太小,不適合剝圓錐" End If End Sub 第三步 菜單欄里點(diǎn)擊運(yùn)行命令輸入?yún)?shù)abc以及拋物線寬度即可得到 一次出差到一個(gè)項(xiàng)目工地去,看到他們對(duì)著電腦上設(shè)計(jì)單位給的CAD圖在一個(gè)點(diǎn)一個(gè)點(diǎn)的的找坐標(biāo)值.方法是用鼠標(biāo)點(diǎn)上一個(gè)點(diǎn),記下(X,Y)后再輸?shù)紼XCEL中,怕一個(gè)人出錯(cuò),得兩個(gè)人來(lái)操作. 后來(lái)有人發(fā)現(xiàn)了一個(gè)好辦法,說(shuō)不用筆來(lái)記(X,Y)了,直接用復(fù)制和粘貼的辦法來(lái)做,這確實(shí)是一大進(jìn)步呀.我問(wèn)他們這一晚上能找多少點(diǎn)呀, 回答說(shuō)做不了多少還老出錯(cuò). 我說(shuō)這樣吧我給你編一個(gè)小程序用吧. 一晚過(guò)后第二天他們拿程序一用都說(shuō)真

8、是省大勁了,又準(zhǔn)又快呀.在CAD中 選 工具-宏-visual basic編輯器, 點(diǎn)thisdrawing 把下面的程序?qū)戇M(jìn)去, 然后點(diǎn)運(yùn)行即可.Attribute VB_Name = "模塊1"Sub abc()Dim x, y As DoubleDim ReturnPoint As VariantDim i As IntegerDim high As SingleDim Ptext, Fname As StringDim textObj As AcadTextDim pointObj As AcadPointDim layerObj As AcadLayerx = 0

9、: y = 0: i = 1: high = 9Fname = InputBox("選取結(jié)束時(shí)，請(qǐng)回到第一點(diǎn)！請(qǐng)給出文件名。")If Fname = "" Then Fname = "PointsDate"Fname = "c:abc" & Fname & ".txt"Set layerObj = ThisDrawing.Layers.Add("PointsData")ReturnPoint = ThisDrawing.Utility.GetPointPtex

10、t = i & ":(" & Round(ReturnPoint(0), 2) & "," & Round(ReturnPoint(1), 2) & ")"Set textObj = ThisDrawing.ModelSpace.AddText(Ptext, ReturnPoint, high)Set pointObj = ThisDrawing.ModelSpace.AddPoint(ReturnPoint)pointObj.Layer = "PointsData"textObj.Layer = "PointsData"pointObj.color = acRedOpen Fname For Output As