Hi, everybody.

I am about to explore parabolic curves and am planning to create some graphics to accompany the theory.
Is there is a "best" way to draw parabolas?

At the moment, I am planning to create two or three parabolas of different focus, for example,

x = (1/(4*0.25)) y^2 and
x = (1/(4*0.75)) y^2

Is there a way to simply input the formula?
Alternately, can data points be generated in a separate application and then manually typed into Inkscape?

Assuming I get this working, my next step is to create curves of other shapes: cubics, quartics, perhaps other exponentials.
So . . . I'm laying the groundwork for future work and would like to make sure I start out in the right direction.

Guidance is much appreciated.

Hello

Inkscape can generate graphics based in math functions with an extension
You can read more about that here:
http://tavmjong.free.fr/INKSCAPE/MANUAL ... ionPlotter

About graphing data from a table, I think in this forum a similar extension was requested. I think Others did it. Please a search about that.

- Or you can make a image of your data plot and then trace it on Inkscape
http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Trace.html

- I think that GNUPLOT can export to SVG format, which can be used by Inkscape. I'm not sure

However, Inkscape it's not a math tool, so some other features can't be present.

Hi

dcb6!8 wrote:At the moment, I am planning to create two or three parabolas of different focus, for example,
x = (1/(4*0.25)) y^2 and
x = (1/(4*0.75)) y^2

Insert But why?.gif here.
Have never seen someone calculating x upon y, usually that would be the other way around.

As mentioned you can use the funcion plotter or the parametric curves extension.


y=1/x should result in a hyperbolic graph. What you have now is not really hyperbolic.
Like x=1000.00/t/x would be much better, where you change t's value for hyperbolas with different focuses.

Edit: was a bit sleepy on it was parabolas, and not hyperbolas, my bad.
y=t*x^2

Remember to add .00 digits to any parameter you want to keep as float otherwise they might be calculated as even values -been there, done that.

(By the way all hyperbolasparabolas are similar to eachother, so for different focuses you can just scale one hyperbola parabola that you have plotted -scale factor is t in the example above.)

Hi.

Geogebra (very extensive math tool) is perfect to graph curves, and has also the ability to export files to .swg

Here is a .swg file, exported from Geogebra, with the two parabolas you defined. Tip - when Inkscape is open, you can drag this svg file into Inkscape window to import it and apply. Also remember that .swg files exported from Geogebra is always collected into one group, and after imported you may have to ungroup it twice if you want to get the parabolas as separated objects.

Hi.

Inkscape got this functionality built in by use of an extension.

Draw a rectangle on the canvas, select the rectangle and select from the dropdown menus:
Extension - Render - Function Plotter

To get "your" parabola enter as in this example:



You will get this result:



(Right Click to download as SVG.)

Have Fun!