graphics with PSTric..

You can see that the curve starts at the first point specified, tangent to theline joining this point to the second and ends at the last point, tangent tothe the line joining this point and the third. The second and third points, inaddition to determining the tangency at the endpoints, also exert a “pull”on the curve. Let’s see in detail how the curve is actually drawn.Suppose the control points are z 1 , z 2 , z 3 , z 4 . First they are joined bystraight lines and the midpoints of each segment is found. Let’s call themz 12 , z 23 and z 34z 12z 23z 34z 1z 2z 3z 4z 1z 2z 3z 4¡Curvy TricksOpen and closed curvesInvisible endsCurve tweakingA new curveOnline L A T E X TutorialPart II – GraphicsPSTricksThese three points are again joined by straight lines and then the midpointsof the two line segments are found. Let them be z 123 and z 234 . These twopoints are joined by a straight line and the mid point of this line segmentis found.E Krishnan, CV Radhakrishnan and AJ Alexconstitute the graphics tutorial team.Comments and suggestions may be mailed totutorialteam@tug.org.inz 123z 234z 123z 234£z 1234c○2002, 2003, The Indian T E X Users GroupThis document is generated by PDFT E X withhyperref, pstricks, pdftricks and pdfscreenpackages in an intel PC running GNU/LINUXand is released under LPPLz 12z 23z 34¢z 1z 2z 3z 4¡z 12z 23z 34¢z 1z 2z 3z 4¡The Indian T E X Users GroupFloor iii, sjp Buildings, Cotton HillsTrivandrum 695014, indiahttp://www.tug.org.in 15/16