(41) Intersection points between circles

12012020, 09:25 AM
Post: #10




RE: Intersection points between circles
Hi Albert,
You wrote: Quote:We should have: pi ≤ alpha ≤ +pi I forgot to mention that I take the absolute figure for computing alpha. I compute alpha = abs(arcsin((y2y1)/z)) (see line 37 of program listing). So I limit it to the interval from 0 to pi/2. You wrote: Quote:sy does not require correction. The results tell me that the correction is needed. Take the following example: x1 = 1, y1= 3, r1 = 4; x2 = 6, y2 = 2, r2 = 5 If computed it with correction I get: sx1 = 1,3106; sy1=0.2651; sx2= 2,8380; sy2 = 1.8732 which is correct If I keep the circles, but use the former circle 2 as circle 1 and vice versa I get: sx1 = 2,8380; sy1= 1.8732; sx2 = 1.3106; sy2 = 0.2651 So the numbers of the intersection points are exchanged, but they still are correct. If I compute without correction of sy (I delete lines 83, 84, 61, 62 of the program) I get: For x1=1, y1=3, r1 = 4, x2 = 6, y2 = 2, r2 = 5 the same results as before. But if I change the number of circles, i.e. x1=6, y1=2, r1=5, x2=1, y2=3, r2=4 I get x1 = 2.8380, y1=5.8380, x2=1,3106, y2=3,7349 which is not correct for the ycoordinates. Perhaps by limiting alpha from 0 to pi/2 and doing the correction both for sx and sy I get correct results? I tested the program with numerous examples and it always delivered correct results. Best Raimund 

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Messages In This Thread 
(41) Intersection points between circles  rawi  11252020, 03:07 PM
RE: Intersection points between circles  Albert Chan  11252020, 06:16 PM
RE: Intersection points between circles  rawi  11252020, 06:48 PM
RE: Intersection points between circles  Albert Chan  11262020, 12:22 AM
RE: Intersection points between circles  Albert Chan  11302020, 02:19 PM
RE: Intersection points between circles  rawi  11302020, 05:19 PM
RE: Intersection points between circles  Albert Chan  11302020, 09:03 PM
RE: Intersection points between circles  Albert Chan  12012020, 12:17 AM
RE: Intersection points between circles  SlideRule  11302020, 08:51 PM
RE: Intersection points between circles  rawi  12012020 09:25 AM
RE: Intersection points between circles  Albert Chan  12012020, 11:59 AM
RE: Intersection points between circles  rawi  12012020, 02:04 PM
RE: Intersection points between circles  Albert Chan  12102020, 01:34 PM

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