RE: [fme] Creating intermediate points along a line

[Russell MILLER]

Dale, timely response, I’ve been at this all day and making progress.   Setting some terminology and history might be useful here.  This is an aerial photogrammetric application.  It’s easy to picture an aircraft flying back and forth creating “runs” and shooting photos along the way.  The points are the centres of the photos, the lines are the flight runs.  The reason we have this problem is because we are working with old photography going back to the 2nd WW when airborne DGPS did not exist, so in order to make spatial data sets we have to create the meta data for each point (photo).   I could not make the densifier work so have moved on to the labeller/coercer route.  I have successfully calculated the interval by calculating the length along a line connecting the points and dividing by the Last Point number less the First Point number less 1. Interval =  ((Last Point number – First Point number)-1)   Once that is done I then produce, as you suggested, labels with “interval” and offset to zero. Using Coercer to change to point geometry it’s all good at this point.   The next step is causing problems.  That is renaming the newly created points to their true number.  The labeller assigns whatever attribute I give it so they all come out the same.  I need to create procedure that checks the First Point adds “1” to it, creates a new attribute for that point, moves to the next point adds “1” to the previous point, creates a new attribute and goes through the line of related points.  When the points on the line are done, the next line of points is started and the procedure continues through the data set.  Then I could remove/rename attributes to suit.   You can see what we are trying to accomplish by going to:   http://www.ntlis.nt.gov.au/imfPublic/airPhotoimf.jsp   Thanks again,   Russell     From: fme@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Dale Lutz Sent: Thursday, 28 September 2006 2:29 PM To: fme@yahoogroups.com Subject: Re: [fme] Creating intermediate points along a line   Hi Russell, I'm not quite sure I understand how the interval should vary for you. Is it a function of the length -- perhaps if you can provide more details on how you'd like the interval calculated we can give some input. Its an interesting application indeed. Perhaps the labeller may be what you need rather than the densifier, let us know if you run into difficulties. Dale On 9/26/06, nichols2bdarwindpi <Russell.Miller@nt.gov.au> wrote: > > Thanks for ideas on creating the points along a line. One more thing > to consider. I have 1oo's maybe a 1000 of these to do and need to > automate the interval calculation. The points are numbered in > sequence along the line so the total number of points I need to add is > =(the last point number - the first point number)-1. I'm attempting to > use ExpressionEvaluator to do the calculation but can't figure out the > _expression_. > > This represents aerial photography flight lines. The first photo taken > is given a number and the rest follow in sequence. I have been given > the first and last frame of each "run" and need to calculate the > frames along the run. > > Thanks for helping out with this. __._,_.___   Your email settings: Individual Email|Traditional Change settings via the Web (Yahoo! ID required) Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe __,_._,___