Hi Mark Thanks for you prompt and detailed reply!
Firstly, regarding creation of a custom coordinate system, only the transformation formula parameters are known. The local grid does not have a defined datum or ellipsoid, thus I believe it is not possible to create a custom coordinate system - correct me if I'm wrong :) I successfully implemented the full transformation using the ExpressionEvaluator - thank you! I agree that it would be worth publishing these parameters and creating a custom transformer I will test your suggested coordinate extraction and replacement functions on a dgn file and let you know the results. All being well this could potentially solve my issue, however it would be much simpler if I could transform the features directly as with Affine or Helmert functions in one step :) Thanks again for you help and will keep you posted! Kind Regards, Carly --- In [email protected], "mark2atsafe" <[EMAIL PROTECTED]> wrote: > > Hi Carly, > If the local grid has known parameters you could create a custom > coordinate system and reproject using that. > > Apart from that, I think that FME has the required computation > abilities, but not directly on the features. What I'd suggest is > grabbing the coordinates of each feature (coordinateFetcher, > coordinateConcatenator or OGCGeometryExtractor), processing the coords > individually, then recreating the feature using the new coords. > > OK - in investigating how to do this, I actually just wrote the > workspace myself. You can find it on fmepedia at... > > http://www.fmepedia.com/index.php/Coordinate_Manipulator > > The workspace is OK, but the best practice part is a work in progress > - ie there's no annotation or bookmarks to explain how it works. I > will do that later today. > > Also - I haven't implemented your full transformation - I just did a > simple offset of x+10, y+5 - I'll leave the full part up to you. I > think you just need to edit the ExpressionEvaluators. If you then make > it into a custom transformer I'd suggest publishing the A, B, C etc > parameters so you can set them up at runtime. > > And speaking of custom transformers - it uses the AttributeParity > transformer from fmepedia - though it is embedded so you shouldn't > need to download it separately unless you want to. > > And to answer your final question - yes you could do it in TCL; there > are folk in this group who would know how better than me. But I do > prefer Workbench by itself when possible. > > If you get this working it'd be nice if you could post it here when > complete to show what it looks like. > > Hope this helps > > Mark > > Mark Ireland, Senior Product Specialist > Safe Software Inc. Surrey, BC, CANADA > [EMAIL PROTECTED] http://www.safe.com > Solutions for Spatial Data Translation, Distribution and Access > > > > > --- In [email protected], "clambert_aamh" <c.lambert@> wrote: > > > > Hello Again! > > > > Further to the below, this is the equation I would like to apply to > > features within a MicroStation Design file > > > > X = C + E(X - A) + F(Y - B) + H((Y - B)^2 - (X - A)^2) + 2G(X - A) > > (Y - B) > > Y = D + E(Y - B) - F(X - A) + G((Y - B)^2 - (X - A)^2) - 2H(X - A) > > (Y - B) > > Z = Z + I > > > > Many Thanks > > Carly > > > > --- In [email protected], "clambert_aamh" <c.lambert@> wrote: > > > > > > Hello :) > > > > > > Could someone please advise if second order conformal > > transformations > > > are possible in FME? > > > > > > I need to transform features to a local grid. Would it be > > possible to > > > script this in TCL? > > > > > > Thank you kindly in advance! > > > > > > Carly > > > > > > Join us at the FME Worldwide User Conference Sept. 21-22, 2006 Vancouver BC Canada. For more information, visit www.safe.com/2006uc. Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/fme/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
