Re: Overlaying a grid on graphics to guide placement

*To*: mathgroup at smc.vnet.net*Subject*: [mg73836] Re: [mg73785] Overlaying a grid on graphics to guide placement*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Thu, 1 Mar 2007 06:25:01 -0500 (EST)*Reply-to*: hanlonr at cox.net

You could use the GridLines option. Needs["Graphics`"]; SetOptions[#,PlotStyle->Red,Frame->True,Axes->False, PlotRange->{Automatic,{0.95,3.05}}]&/@ {Plot,LogLogPlot,LogLinearPlot}; DisplayTogetherArray[{ {LogLogPlot[Exp[-x+1],{x,0,1}, GridLines->Automatic], LogLogPlot[Exp[-x+1],{x,0,1}, GridLines->{Table[10^-n,{n,0,5}], Table[y,{y,1,3,.5}]}]}, {LogLinearPlot[Exp[-x+1],{x,0,1}, GridLines->Automatic], LogLinearPlot[Exp[-x+1],{x,0,1}, GridLines->{Table[10^-n,{n,0,5}],Automatic}]}, {Plot[Exp[-x+1],{x,0,1}, GridLines->Automatic]}}, ImageSize->800]; Bob Hanlon ---- "Michael A. Gilchrist" <mikeg at utk.edu> wrote: > Hi, > > I'd like to develop a function which overlays a grid on a graphics such as > a plot to help with the placement of additional graphics object through > things like Epilog or Prolog. > > I've taken a stab at it below, > > (*construction of grid*) > imax = jmax = 4; > step = 0.25; > > hlines = > Table[{If[j == 0., Black, LightGray], > Line[{{-imax, j}, {imax, j}}]}, {j, -jmax, jmax, step}]; > > vlines = > Table[{If[j == 0., Black, LightGray], > Line[{{ j, -imax}, {j, imax}}]}, {j, -jmax, jmax, step}]; > > hlabels = Table[Text[j, {j, 0}, {1, 1.1}], {j, -jmax, jmax, 1}]; > vlabels = Table[Text[j, {0, j}, {1.1, 1}], {j, -jmax, jmax, 1}]; > > grid = Join[hlines, vlines, hlabels, vlabels]; > > (* ooh it looks good on its own*) > Show[Graphics[grid]] > > > (*not so good here*) > LogLogPlot[Exp[-x + 1], {x, 0, 1}, > Epilog -> grid] > > Plot[Exp[-x + 1], {x, 0, 1}, > Epilog -> grid] > > Show[GraphicsArray[{ > {LogLogPlot[Exp[-x + 1], {x, 0, 1}, > DisplayFunction -> Identity]}, > {Plot[Exp[-x + 1], {x, 0, 1}, > DisplayFunction -> Identity]}}], Epilog -> grid] > > > If you run these commands you'll see that my attempt is inelegant and it > doesn't work very well. Ideally, the grid would (a) adjust itself so that > its boundaries are within the graphics object and (b) adjust the spacing > and labeling so that the grid lines are frequent enough to be informative > but not obscure the entire figure. > > If any one has any suggestions I'd greatly appreciate hearing them. > > Thanks in advance. > > Mike > > ----------------------------------------------------- > Department of Ecology & Evolutionary Biology > 569 Dabney Hall > University of Tennessee > Knoxville, TN 37996-1610 > > phone:(865) 974-6453 > fax: (865) 974-6042 > > web: http://eeb.bio.utk.edu/gilchrist.asp