Stephan Eggermont, During this holiday I help my son with a data mining project, we use PlotMorph for 2D graphic. We have this little fix to PlotMorph: ------------------------------------------------------------------------ PlotSeties>>scaleTo: anRectangle height: heightInteger maxPoint: maxPoint minPoint: minPoint     | drawExtent scaleFrom scaleTo |     *drawExtent := maxPoint - minPoint.*     drawExtent isZero         ifTrue: [^ self].     scaleFrom := 0 @ 0 rectangle: drawExtent.     scaleTo := anRectangle.     points do:         [:point |             | tempPoint |             tempPoint := point - minPoint scaleFrom: scaleFrom to: scaleTo.             point scaledPoint: tempPoint x @ (heightInteger - tempPoint y)] ------------------------------------------------------------------------ Without this change, the code below does not work properly (scaling is not right): ------------------------------------------------------------------------ | m | m := PlotMorph plotPoints: { 0@0 . 0.59@0.88. 0.49@0.49  }. m openInWindow. ------------------------------------------------------------------------ Thanks Hilaire -- Dr. Geo http://drgeo.eu