In article <34590a0b-3ceb-456d-93ae-522b32dec017@c3g2000yqd.googlegroups.com>, Arkward <sunjigang1965@yahoo.com.cn> wrote: >Could anyone suggest me methods on how to calculate shortest distance >between two point along a surface. The surface is not standard one >like sphere. >Thanks. Why do you want to know? I use to have students construct geodesics numerically via matlab, but calculus of variations can get analyitical solutions of the minimal geodesic at times. -- Steven Bellenot http://www.math.fsu.edu/~bellenot Professor and Associate Chair phone: (850) 644-7405 Department of Mathematics office: 223 Love Florida State University email: bellenot at math.fsu.edu

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1/15/2010 5:40:04 PM

On Jan 15, 8:27=A0am, Arkward <sunjigang1...@yahoo.com.cn> wrote: > Could anyone suggest me methods on how to calculate shortest distance > between two point along a surface. The surface is not standard one > like sphere. > Thanks. You want a "geodesic". See, eg., http://www.maplesoft.com/applications/view.aspx?SID=3D34940&view=3Dhtml (which deals directly with this problem in a Maple framework) or http://mathworld.wolfram.com/Geodesic.html (general theory) or http://www.physicsforums.com/showthread.php?t=3D169560 (some examples). R.G. Vickson

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1/15/2010 5:43:06 PM

On 15 Jan, 17:40, fakeu...@invalid.domain wrote: > In article <34590a0b-3ceb-456d-93ae-522b32dec...@c3g2000yqd.googlegroups.= com>, > > Arkward =A0<sunjigang1...@yahoo.com.cn> wrote: > >Could anyone suggest me methods on how to calculate shortest distance > >between two point along a surface. The surface is not standard one > >like sphere. > >Thanks. > > Why do you want to know? I use to have students construct geodesics > numerically via matlab, but calculus of variations can get analyitical > solutions of the minimal geodesic at times. > -- > Steven Bellenot =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0http://www.math.fsu.edu/~b= ellenot > Professor and Associate Chair =A0 =A0 =A0 =A0 =A0 =A0 =A0 phone: (850) 64= 4-7405 > Department of Mathematics =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0= office: 223 Love > Florida State University =A0 =A0 =A0 =A0 =A0email: bellenot at math.fsu.e= du Thank you for your advice. In an algorithm, distance between two points of data set is shortest graph distance as an approximation of geodesic distance. I plan to simulate the surface by aggression then calculate the geodesic distance on the simulated surface.

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1/15/2010 9:36:37 PM

Could anyone suggest me methods on how to calculate shortest distance between two point along a surface. The surface is not standard one like sphere. Thanks. In article <34590a0b-3ceb-456d-93ae-522b32dec017@c3g2000yqd.googlegroups.com>, Arkward <sunjigang1965@yahoo.com.cn> wrote: >Could anyone suggest me methods on how to calculate shortest distance >between two point along a surface. The surface is not standard one >like sphere. >Thanks. Why do you want to know? I use to have students construct geodesics numerically via matlab, but calculus of variatio...

Hi, Given a spatial point A (x,y,z), can anyone tell me how to calculate the distance between A and B (100,100,100)? Thanks D bsder wrote: > Hi, > > Given a spatial point A (x,y,z), can anyone tell me how to calculate the > distance between A and B (100,100,100)? > I will need to do it in C with include <math.h> > Thanks > D "bsder" <bsder@bsder.com> wrote in message news:ci5Be.41603$oJ.30139@news-server.bigpond.net.au... > Hi, > > Given a spatial point A (x,y,z), can anyone tell me how to calculate the > distance between A an...

I have a ellipsoid "defined" at a point E. I have its shape information stored: elpsd_props{i,1}(:,:) = [centroid xyz coords; unit semi-axis vector a; unit semi-axis vector b; unit semi-axis vector c; semi-axis lengths a,b,c] I have a matrix called astrd_int which holds a massive grid 3-D points. All of these points lie outside of the ellipsoid. I call these interior points (we're inside another shape). I wish to find the minimum distance from...

Dear all, I want to calculate the ' great circle distance' between two points on the surface of an ellipsoid. Though because of the extra radius, the great circle distance is not what I am looking for. Also I have not a center of the ellipsoid on [0,0,0], which makes the calculation more difficult, besides this I only have the cartesian coordinates of the two points and the center. This is what I have now, anyone knows how to calculate this distance? % construct of center ellipsoid a= rand(1,3)*10 cx=a(1) cy=a(2) cz=a(3) % construct the three different radii b= rand(...

I have a 2-D matrix of sampled values on a regular, uniform grid of x and y. The data can be analogied to being vertical height at every point. I then have an arbitrary point (a,b,c) and I want to know the shortest distance from that point to the sampled surface. The x and y coordinates of the point (a,b,c) will coincide with those on the sampled grid (so it's not completely arbitrary). I know I can find the distance to every point on the surface and find a minimum, but that doesn't acount for when the shortest distance is to a face or edge of the surface rather than a point. ...

Is there an easy formula for this ? For example, assume you have two points on each lines and the point the distance must go through. On Jul 11, 4:05 am, raphfrk <raph...@netscape.net> wrote: > Is there an easy formula for this ? > > For example, assume you have two points on each lines and the point > the distance must go through. To clarify, you have two lines, say L1 and L2, and a point P. You want to find the length of the shortest line segment that passes through P and has one endpoint on L1 and the other endpoint on L2. Is that correct? Is this in 2-D or 3-D? Dave ...

I really need someone's help on this. I am trying to acquire an image which has two black points in it. So, i mean i need some matlab codes which can help me to acquire the image automatically by identifying the two black points, and then find the distance automatically with a line drawn between the two black points. I am stuck in this automated process. Can't really think about any codes which can do that in Matlab? Can someone please please help me to get my problem solved soon? Thanks Siddharth Magazine wrote: > I really need someone's help on this. I am trying to ac...

Hi. I was wondering, is it possible to write all the required codes in a .m file in Matlab, which will then become an automatic process for acquiring different images, and then processing it, or do i have to enter a given code everytime to execute the results. Can't this process be automated? Please help me on this topic. Thanks "Siddharth Magazine" <magazinesiddharth@hotmail.com> wrote in message news:hvc8rb$j6g$1@fred.mathworks.com... > Hi. I was wondering, is it possible to write all the required codes in a > .m file in Matlab, which will then become an ...

Hallo, I want to calculated the distance from one point to a point on a 3D surface. If one creates a cylinder using the following command t = 0:pi/10:2*pi; [X,Y,Z] = cylinder(2+cos(t)); surf(X,Y,Z); you get a nice surface made with polygons only in the plot. I want to have the quite simple surface in memory so that I can access it. It is possible to describe surfaced using some kind of polygon...? I have already tried to calculate hundreds of point of the cylinder. But it takes a lot of time, you only get some points of the whole surface and plotting each of this hundreds point tak...

I have a large matrix, I want to calculate the distance of each point of the matrix from one certain point which is also in the matrix. if I used a loop, for i= 1:m for j= 1:n dist(i,j) = sqrt((i-x0)^2 + (j-y0)^2)); end end Is there any fast way to do this, because the matrix I am processing is large. Thanks a lot. "JohnMC " <nirmathink@gmail.com> wrote in message <i4hbuo$fd2$1@fred.mathworks.com>... > I have a large matrix, I want to calculate the distance of each point of the matrix from one certain point which is also in the matrix. >...

In an equilateral triangle ABC, I've the the coordinates of two of the points (A and B). Is it possible to calculate the coordinates of the third (C)? I've tried using pythagoras's theorem but this only seems to work when one of the triangle sides are parallel to an axis. Alternativly (I dont know whether this is easier or not) calculate coordinates of B and C given the points A and M, where M is the midpoint of BC. Any help or links to helpful threads appriciated. Philbo philbo@gmail.com (Philbo) dixit: >In an equilateral triangle ABC, I've the the coordinates of two ...

Am undergoing a project based on vehicle speed measurement using uncalibrated camera. I used distance vector algorithm to find the distance between to points as i was not well versed in MATLAB can u help me out by saying the algorithm and coadings for finding the distance between two points using distance vector algorithm....tanx... "saravanan jayachandran" <saravanan.j.yoga@gmail.com> wrote in message <j4qtm5$ddb$1@newscl01ah.mathworks.com>... > Am undergoing a project based on vehicle speed measurement using uncalibrated camera. I used distance vector algorithm to ...

In MapInfo, I want to calculate the average distance between one specific point and a whole series of other points. I know I can use the ruler, but I'm dealing with a situation where I want to examine 150 points in relation to a point. And to do this many times. I'm a crime analyst, looking at the distance between a series of burglaries and one fixed point (e.g. a prolific offender's home address). Is there an automatic way of calculating these distances? My points each have a British eastings and northings set of co-ordinates. Thanks Martin Do it like this: ...

Hi I am very new in matlab. Can any body help me to figure it out? Lets, I have a matrix (10 X 20), I want to calculate the distance of each point of the matrix from one certain point (another array of xy point). I want to check the distance of all points in the matrix with respect to xy point (first with respect to 1st xy coordinate then 2nd and to the end.) I want to use the loop system. Example data: (X1, Y1) (x1, y1) (X2, Y2) (x2, y2) (X3, Y3) (x3, y3) (..., ....) (..., ....) (..., ....) (..., ....) (..., ....) (..., ....) (Xn, Yn) (xm, ym) for I = 1, n for I = 1, ...

Hi I want to measure distance between two random lines. i.e., from starting point of firstline to starting point of second line........ to end point of first line to endpoint of second line. (and also ihave to draw a graph of distance) can you help in this regard ? thank you ...

Hello :) I've got the coordinates of two different Tows. Now I want to calculate the difference between them. Can anyone tell me, what I have to do for this? The coordinates are in the following format: Adenau; 6.93333; 50.3833 Firste the name of the town, then the longitude and then the latitude. Thanks in advance :) "Janine Schwarz" <Dark_Haruka@web.de> wrote in message news:d6qris$bbl$1@online.de... > Hello :) > > I've got the coordinates of two different Tows. Now I want to calculate > the difference between them. Can anyone te...

I have a database that has Latititude and Longitude on it, and I need to calculate the distance in miles between two facilities. Has anyone come across something like this? Thanks. _______________________________ Bruce A. Johnson Senior Data Analyst Solucient, LLC 1007 Church Street Evanston, IL 60201 (847) 424-4249 bjohnson@solucient.com=20 This message is a private communication. It may contain information that = is confidential=20 and legally protected from disclosure. If you are not an intended = recipient, please do=20 not read, copy or use this message or any attachments, and do not =...

How can i write the set of points between point A and point B? On 8/22/2012 8:40 PM, Weam Zohdy wrote: > How can i write the set of points between point A and point B? That's an infinite set theoretically. What particular set did you have in mind? -- On 23 Aug., 03:40, "Weam Zohdy" <weamzohd...@yahoo.com> wrote: > How can i write the set of points between point A and point B? t*A+(1-t)*B for 0<=t<=1. Best wishes Torsten. ...

Hi, I am looking for some source code that can compute a shortest ( or near shortest) path between starting point S and destination point T in a polygonal environment, which may have polygonal obstacles ( or holes) in it. Can someone give me the code, or any suggestions where to find it? Thanks, swh On Fri, 10 Oct 2003, pipi wrote: > > I am looking for some source code that can compute a shortest ( or near > shortest) path between starting point S and destination point T in a > polygonal environment, which may have polygonal obstacles ( or holes) in it. > > Ca...

Hi I would like to know how to calculate the actual distance between two points given their pixel locations in the image without using stereo vision (i.e., by using only one camera). Height and angle of depression of the camera are known... Thanks Ankur ...

Hello all, I would like to know if anyone has any algorithm code for calculating the perpendicular distance between two surfaces where sometimes the surfaces cross with one inside the other. I would like to keep track of the sign when this happens. My surfaces are in points and indeces format. Cheers G Gregthom <gregthom99@yahoo.com> wrote in message <28868426.1192545143285.JavaMail.jakarta@nitrogen.mathforum.org>... > Hello all, > > I would like to know if anyone has any algorithm code for calculating the perpendicular distance between two surfaces where sometimes ...

Can't you use the pythagorean theorum for this? Or do you need say, road mileage? -----Original Message----- From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of Bruce Johnson Sent: Tuesday, September 07, 2004 9:00 AM To: SAS-L@LISTSERV.UGA.EDU Subject: Distance between two points I have a database that has Latititude and Longitude on it, and I need to calculate the distance in miles between two facilities. Has anyone come across something like this? Thanks. _______________________________ Bruce A. Johnson Senior Data Analyst Solucient, LLC 1007 Church Street Evansto...

Hello! I am very new to programming. I have a few questions on how to set up some calculations I need to implement. Here is all I have. The integers below I am using are just as an example. My 3-D vetors are in the form of (x,y,z). However, I do not know if I set it up correctly to reflect that. There should be 5 anchors and 9 seats all in the form of a location (x,y,z). >> Anchors = [1 1 1; 2 2 2; 3 3 3; 4 4 4; 5 5 5] Anchors = 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5 >> Seats = [1 2 3; 2 3 4; 3 4 5; 4 5 6...

Hi, Suppose you have two vectors describing coordinates in an image: x=[3 2 1]; y=[7 8 9]; The distances between each point are >> norm(y(1)-x(1)) ans = 4 >> norm(y(2)-x(2)) ans = 6 >> norm(y(3)-x(3)) ans = 8 QUESTION: Is there a vectorized way of getting the distances element-by-element? Thanks, -Michael Michael <michael.j.krause@gmail.com> wrote in message <1193028351.414101.104300@z24g2000prh.googlegroups.com>... > Hi, > > Suppose you have two vectors describing coordinates in an image: > > x=[3 2 1]; > y=[7 8 9]; &...

Hi! I've a table with a list of record that have latitude and longitude I've know new point with a position (new lati and new longi) how can I show all records that have a distance <= of XX Kilometers?? Is it possible? Thanks On 29/12/10 23:55, Sarah wrote: > Hi! I've a table with a list of record that have latitude and > longitude > > I've know new point with a position (new lati and new longi) > > how can I show all records that have a distance <= of XX Kilometers?? > > Is it possible? You need a great circle calculator, and to calculate...