http://www.mapleprimes.com/questions/144193-Picking-Points-On-A-3D-Plot en-us 2026 Maplesoft, A Division of Waterloo Maple Inc. Maplesoft Document System Tue, 09 Jun 2026 09:30:04 GMT Tue, 09 Jun 2026 09:30:04 GMT The latest answers and comments added to the Question, Picking points on a 3D plot http://www.mapleprimes.com/images/mapleprimeswhite.jpg http://www.mapleprimes.com/questions/144193-Picking-Points-On-A-3D-Plot http://www.mapleprimes.com/questions/144193-Picking-Points-On-A-3D-Plot?ref=Feed:MaplePrimes:Picking points on a 3D plot:Comments#answer144195 <p>You have to extract the z-values of the plot, and calculate the corresponding x- and y-values.<br>I give an example</p> <pre>restart;<br>p := plot3d(x^2-y^2, x=-1..1,y=-1..2):<br>pdata := plottools:-getdata(p); zvals := pdata[3]:<br># the x- and y-range are divided in 48 equal intervals.<br># we compute the x- and y-values in this grid:<br>h := 2/48: xvals := seq(evalf(h*i),i=-24..24);<br>h := 3/48: yvals := seq(evalf(h*i), i=-16..32);<br># an arbitrary point on the graph:<br>[xvals[9],yvals[23],zvals[9,23]];<br># check:<br>xvals[9]^2-yvals[23]^2;<br><br><br></pre> <p>You have to extract the z-values of the plot, and calculate the corresponding x- and y-values.<br>I give an example</p> <pre>restart;<br>p := plot3d(x^2-y^2, x=-1..1,y=-1..2):<br>pdata := plottools:-getdata(p); zvals := pdata[3]:<br># the x- and y-range are divided in 48 equal intervals.<br># we compute the x- and y-values in this grid:<br>h := 2/48: xvals := seq(evalf(h*i),i=-24..24);<br>h := 3/48: yvals := seq(evalf(h*i), i=-16..32);<br># an arbitrary point on the graph:<br>[xvals[9],yvals[23],zvals[9,23]];<br># check:<br>xvals[9]^2-yvals[23]^2;<br><br><br></pre> 144195 Tue, 05 Mar 2013 20:29:53 Z Adri van der Meer Adri van der Meer