|
发表于 2007-1-12 09:22:11
|
显示全部楼层
来自: 中国辽宁营口
autocad的功能极其强大,使用基本画图命令、计算、编程都是可选的做图方法。“条条大路通罗马”,用最简洁的途径,得到最准确的结果,才能称得上是技巧。限制使用某些基本做图命令而不去尝试autocad其它更强大的功能,窃以为不妥。试问:谁能用画圆的命令生成一条直线?
( a( D# K' F8 r以下是用VBA求解的过程。
5 b5 |0 b* b9 q9 R; v附:源代码
程序加载和做图过程
程序注释用图
# {" X8 q9 L( J% {" X
" z! x; p! h! Y% ~7 q1 ~4 b
Sub NT()( d7 j% \# f3 v% N, e( ^: P
On Error GoTo 10 '发生错误时退出程序
! p! M3 M4 n) T, r. q6 A3 N( v/ V
8 F3 i& E2 S& A Dim A As Variant 'A点坐标
2 q$ K% \$ {6 H. w/ V0 ?' ] Dim C As Variant 'C点坐标
4 T7 E1 n7 N7 Z* H. N Dim B(2) As Double 'B点坐标 T: H j; a9 f5 ^( B* Z+ A
Dim P1 As Variant '直线12起点坐标% J) Z" \, }* \+ R0 U- R5 R. a5 A
Dim P2(2) As Double '直线12端点坐标- o5 D) O0 p" ^3 m
Dim R As Double '圆Y半径
& @1 R; }' D5 l Dim LineAC As AcadLine '直线AC& w3 k: y; P% R0 g
Dim Y As AcadCircle '圆Y
* r" v) v0 a) ~* T! z. }/ F+ Q Dim OC As Double 'C点到直线AB中点的高
5 Y9 C5 D6 M& `% s2 d* c Dim AB As Double '直线AB长度' _- ~' [3 @- k* O
Dim M1 As Double '迭代运算左边界点的横坐标$ | m& i7 t% T* K# U* ^
Dim M2 As Double '迭代运算右边界点的横坐标
" e6 x) D5 b2 X$ x! c, F* n5 O Dim Yc(2) As Double '题目中拉伸点的坐标* T5 w/ ~8 ^1 p* X" ]) w1 n
Dim X As Double '圆Y与直线AB交点的横坐标
# {" S# T9 U0 N: u5 {$ P Dim X2 As Double '圆Y与直线AB交点的横坐标
" |' P: \, y1 O3 h" q. ^ Dim S As Long '曲线拟合点数量(3~32767)
5 b$ U# h K" M5 Q2 w+ H1 x6 R Dim K() As Double '拟合点坐标
/ x% ^2 {2 T- r' m0 ^' u' j+ G/ b Dim St(2) As Double '曲线起点切向, }3 I- ]6 n) `. ]
Dim Et(2) As Double '曲线端点切向9 y6 P6 Y2 g, l2 U8 U- b
Dim I As Long '循环变量* W9 V1 n8 A/ I, }9 q( @1 D# s
, S( ]7 r3 @' d
With ThisDrawing$ @2 r! V" k& e
A = .Utility.GetPoint(, vbCrLf & "指定A点位置:") '指定A点位置
) |; E7 A0 a m Do '指定C点位置,当用户给出的位置不在规定范围时重新要求指定位置。4 B: z, n) x+ K1 k& A7 W E, k
C = .Utility.GetPoint(A, vbCrLf & "指定C点位置(在A点右上方):")
+ g% C2 w& C3 b- k+ i6 K If C(0) > A(0) And C(1) > A(1) Then Exit Do$ h9 U" a0 k- _7 `# j
Loop0 n r: e5 G6 S% [
OC = C(1) - A(1) '计算B点坐标+ T% C0 N2 g+ W5 B( |7 i* ^
AB = 2# * (C(0) - A(0))
& U1 U+ z% F4 J% i1 C0 Q$ ? B(0) = A(0) + AB
( _/ I( E" G; W5 `" p/ t2 b" _ B(1) = A(1)# Z( Z- D, H; V/ O: B, {9 s
Set LineAC = .ModelSpace.AddLine(A, C) '画AC直线; o C: Y' I1 t: d) E
.ModelSpace.AddLine A, B '画AB直线7 C* V) C$ L, {0 U
.ModelSpace.AddLine B, C '画BC直线
7 }) S2 M! m6 H1 U6 M Do '指定圆Y半径,当用户给出的半径不在规定范围时重新要求指定半径。
' L i. W, R, l R = .Utility.GetDistance(A, vbCrLf & "指定圆的半径(小于AC长度):")
0 {+ A) E$ u2 w J( t If R < OC And R > 0 Then Exit Do
$ z* q' B' P1 \* q% b" |7 m5 Y Loop6 `, o1 Q! F! ]
Set Y = .ModelSpace.AddCircle(A, R) '以A点为圆心画圆Y* B4 g7 n* X( R
P1 = .Utility.GetPoint(, vbCrLf & "指定直线12位置:") '指定直线12上的一个点( _; H4 Z8 x8 u! y
P1(1) = C(1) '计算直线12起端点坐标
+ s% |- Z/ g; ]1 J; M- o P2(0) = P1(0)! X; N* h8 I, }5 T# S
P2(1) = A(1)
7 ~0 q3 u3 u5 R$ ~* ]% l .ModelSpace.AddLine P1, P2 '画直线12" c) i$ S( c( D2 Z9 g; a
! _& k' \+ ^* o! u
M1 = P1(0) - R '以直线12左侧R远为迭代运算初始左边界, R3 k& [- _; n% M" n8 V
M2 = P1(0) + R '以直线12右侧R远为迭代运算初始右边界
( T7 N; e' T' l. o Yc(1) = A(1) '拉伸点纵坐标与A点相同1 b8 j D" H2 q! e6 d% z
Do '迭代运算
( ~3 w% O2 @ W o1 f4 K1 h Yc(0) = (M1 + M2) / 2# '把拉伸点置于两边界中点,计算此时圆Y与AC交点横坐标5 \7 w/ t: N! G
X = C(0) + (Yc(0) - C(0)) * (Sqr((Yc(0) - C(0)) ^ 2 + OC ^ 2) - R) / Sqr((Yc(0) - C(0)) ^ 2 + OC ^ 2)- E9 X+ m- M6 m
If X = P1(0) Then '交点与直线12重合,结束运算
+ e- U" l" A1 c; t Exit Do
3 i5 W: |* D7 ^0 C ElseIf Yc(0) = M1 Then '拉伸点与左边界重合,边界已收敛到双精度数据极限,结束迭代运算, [; O9 ~& {: }0 d4 n
'以右边界为拉伸点,计算交点,并与左边界为拉伸点时的结果比较,取精度高者为最终结果
, S6 j% [$ J+ `7 b. p X2 = C(0) + (M2 - C(0)) * (Sqr((M2 - C(0)) ^ 2 + OC ^ 2) - R) / Sqr((M2 - C(0)) ^ 2 + OC ^ 2)
4 O- u; ?. b4 S' C" p- A If Abs(X2 - P1(0)) < Abs(X = P1(0)) Then Yc(0) = M24 [) Y5 O# J* K2 {% ~
Exit Do) p' N# Z# V ]4 Z5 k/ _: ]
ElseIf Yc(0) = M2 Then '拉伸点与右边界重合,边界已收敛到双精度数据极限,结束迭代运算- L; f1 b" a* K5 @7 n3 q9 q
'以左边界为拉伸点,计算交点,并与右边界为拉伸点时的结果比较,取精度高者为最终结果
9 a4 `- I# _8 C @& o X2 = C(0) + (M1 - C(0)) * (Sqr((M1 - C(0)) ^ 2 + OC ^ 2) - R) / Sqr((M1 - C(0)) ^ 2 + OC ^ 2)
' ]0 R! ^5 h, H" B5 \9 k3 D If Abs(X2 - P1(0)) < Abs(X = P1(0)) Then Yc(0) = M1- L1 y& t- z- D. V1 l3 c
Exit Do# P: a6 x5 X& g8 h, V- M6 A4 C9 B
ElseIf X < P1(0) Then '试运算的交点在直线12左侧,将左边界收敛到现拉伸点,重新运算
" F/ z Z+ r% w4 N" z2 e M1 = Yc(0)
1 O/ O4 o8 ^9 g* u6 Z# n Else '试运算的交点在直线12右侧,将右边界收敛到现拉伸点,重新运算6 B# }2 y9 i! t9 y& X
M2 = Yc(0)
6 P2 I! F. @' x' i& M End If" U2 K' @% J( U2 q0 J+ n
Loop# B) r% O1 X/ v) ]3 k6 V5 V3 S( D: K7 y
LineAC.StartPoint = Yc '按计算结果移动直线AC起点3 k9 P1 n! c4 Z7 x1 K; h8 \
Y.Center = Yc '按计算结果移动圆Y; T/ N* D5 A# L. {' Y
9 _( E& g/ @ Q) `( h1 ]) p' x, I) i, l
Do ''指定拟合点数量,当用户给出的数量不在规定范围时重新要求指定数量。+ F) Z, h* \3 t: I/ ~
S = .Utility.GetInteger(vbCrLf & "指定曲线拟合点数量(3到32767之间正整数):")2 f2 n: F3 K0 X$ H$ ^
If S > 2 Then Exit Do
. _- |0 \+ x. F& x/ k# v6 ?. ?* m Loop
2 S9 w" Z+ M- s$ G2 K/ a ReDim K(3 * S - 1) '按拟合点数量重新定义数组上界# S. X' \" {0 _* I* R7 k2 p- |
For I = 0 To S - 1 '圆Y和直线AC起点以直线AB长度的(S-1)分之一为步长从左向右移动,逐点计算圆Y和直线AC交点,做为拟合点坐标& p9 j9 a% p$ P8 b! }
Yc(0) = A(0) + I / (S - 1) * AB4 B' S# r7 p# h& w7 x
K(I * 3) = C(0) + (Yc(0) - C(0)) * (Sqr((Yc(0) - C(0)) ^ 2 + OC ^ 2) - R) / Sqr((Yc(0) - C(0)) ^ 2 + OC ^ 2)
4 `1 ] G5 P! }5 z, m K(I * 3 + 1) = A(1) + Sqr(R ^ 2 - (K(I * 3) - Yc(0)) ^ 2)8 J8 u- }( Y( m4 z+ r& G! n$ `
Next; J9 `5 y3 a5 W( Y- q* u
St(0) = 1 '曲线起点切向$ r; k q* X. i3 ^ D
St(1) = Sqr(R ^ 2 - (K(1) - A(1)) ^ 2) / (R ^ 2 / (K(1) - A(1)) + (C(1) - K(1)) * R ^ 2 / (K(1) - A(1)) ^ 2 - (K(1) - A(1)))& i1 ~7 K: ~* N: _4 @- n
Et(0) = 1 '曲线端点切向
8 i n/ @8 s" l" s- { Et(1) = -St(1)
3 o4 a5 I- l. z .ModelSpace.AddSpline K, St, Et '画样条曲线
h; b. Z. G1 r5 l- Y- U: A% {+ \* N End With
0 O* n. H% B9 U1 j$ o1 T10
2 b% [& |3 y9 V4 ~# bEnd Sub
# G* r* Z9 ^6 T
8 ]! Z/ n+ O5 T: `. B( X[ 本帖最后由 woaishuijia 于 2007-1-12 19:24 编辑 ] |
-
-
nt.rar
12.66 KB, 下载次数: 12
程序和附图
|