## Re: [Inkscape-user] Extracting formulas from curves?

 Re: [Inkscape-user] Extracting formulas from curves? From: Philip Rhoades - 2009-01-30 12:27:02 ```Felipe, I have a statistical relationship in mind and I find it is convenient to use Inkscape to create the graphs of what I think it should look like under different conditions. Having done that, it would be nice to be able to extract the formula for each curve that I have drawn. The curve of the relationship that I am thinking of should have only a single y value for each x coordinate, so it should be a function. Thanks, Phil. > From: Felipe Sanches - 2009-01-30 02:02 > well.. maybe. > it is a bezier curve. It is a parametric curve whose coordinates are > defined by quadractic equations: > x(t) = a*t² + b*t + c > y(t) = d*t² + e*t + f > finding the values of a,b,c,d,e and f involves looking at the > coordinates of the control points of that curve and doing a bit of > math > Not all bezier curves can be described as 1 parameter functions, > though... I think that it is indeed possible to do that with the one > you provided since it appears to have a single y value for each x > coordinate, thus it satisfy the requirements to be called a function. > what are you trying to do with this math stuff? > On Thu, Jan 29, 2009 at 10:14 PM, Philip Rhoades wrote: > > People, > > > Is there a way of extracting the formula for the curve from the attached svg > > ie in something resembling a conventional y = f(x) format? > > > Thanks, > > > Phil. > -- > Philip Rhoades > > GPO Box 3411 > Sydney NSW 2001 > Australia > E-mail: phil@... -- Philip Rhoades GPO Box 3411 Sydney NSW 2001 Australia E-mail: phil@... ```

 Re: [Inkscape-user] Extracting formulas from curves? From: Philip Rhoades - 2009-01-30 12:27:02 ```Felipe, I have a statistical relationship in mind and I find it is convenient to use Inkscape to create the graphs of what I think it should look like under different conditions. Having done that, it would be nice to be able to extract the formula for each curve that I have drawn. The curve of the relationship that I am thinking of should have only a single y value for each x coordinate, so it should be a function. Thanks, Phil. > From: Felipe Sanches - 2009-01-30 02:02 > well.. maybe. > it is a bezier curve. It is a parametric curve whose coordinates are > defined by quadractic equations: > x(t) = a*t² + b*t + c > y(t) = d*t² + e*t + f > finding the values of a,b,c,d,e and f involves looking at the > coordinates of the control points of that curve and doing a bit of > math > Not all bezier curves can be described as 1 parameter functions, > though... I think that it is indeed possible to do that with the one > you provided since it appears to have a single y value for each x > coordinate, thus it satisfy the requirements to be called a function. > what are you trying to do with this math stuff? > On Thu, Jan 29, 2009 at 10:14 PM, Philip Rhoades wrote: > > People, > > > Is there a way of extracting the formula for the curve from the attached svg > > ie in something resembling a conventional y = f(x) format? > > > Thanks, > > > Phil. > -- > Philip Rhoades > > GPO Box 3411 > Sydney NSW 2001 > Australia > E-mail: phil@... -- Philip Rhoades GPO Box 3411 Sydney NSW 2001 Australia E-mail: phil@... ```