Re: Plotting

*To*: mathgroup at smc.vnet.net*Subject*: [mg28736] Re: [mg28694] Plotting*From*: Matt.Johnson at autolivasp.com*Date*: Fri, 11 May 2001 03:38:51 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Yahsi- That is one function that they should definitely include. But they don't. So here's one for two functions. It will take some tailoring to get the best output and the programming isn't too pretty, but it works. -matt In[1]:= Off[General::spell, General::spell1] In[2]:= f1[x_] := Sin[x]; f2[x_] := x^2; In[4]:= (* f1 will be plotted on the left - hand axis, f2 will be plotted on the right - hand axis. They both must be functions in just one variable. xmin and xmax specify the plot range. Depending on the functions, the function may need to be tweaked for the appropriate minimum and maximum \ values. *) twoAxisPlot[f1_, f2_, xmin_, xmax_] := Module[{ptext1, ptext2, plotPoints1, plotPoints2, min1, min2, max1, max2, p1, p2, rhsTicks}, (* Get the textual form of each plot and find the max and min y - values. *) ptext1 = Plot[f1[x], {x, xmin, xmax}, DisplayFunction -> Identity] // InputForm; ptext2 = Plot[f2[x], {x, xmin, xmax}, DisplayFunction -> Identity] // InputForm; plotPoints1 = Cases[Cases[ptext1, _Line, \[Infinity]], _List, 2] [[1]]; plotPoints2 = Cases[Cases[ptext2, _Line, \[Infinity]], _List, 2] [[1]]; min1 = Min[Transpose[plotPoints1][[2]]]; max1 = Max[Transpose[plotPoints1][[2]]]; min2 = Min[Transpose[plotPoints2][[2]]]; max2 = Max[Transpose[plotPoints2][[2]]]; (* Create the plots, with the second plot scaled to the left - hand axis *) p1 = Plot[f1[x], {x, xmin, xmax}, DisplayFunction -> Identity]; p2 = Plot[f2[x]*(max1 - min1)/(max2 - min2) + max1 - max2*(max1 - min1)/(max2 - min2), {x, xmin, xmax}, DisplayFunction -> Identity]; (* Define the RHS tickmarks *) rhsTicks = Map[Chop[#] &, Transpose[{Range[min1, max1, (max1 - min1)/5], Range[min2, max2, (max2 - min2)/5]}]]; (* Combine and display the plots *) Show[p1, p2, Frame -> True, DisplayFunction -> $DisplayFunction, FrameTicks -> {Automatic, Automatic, None, rhsTicks}];]; In[6]:= twoAxisPlot[f1, f2, 0, 10] Yahsi <yahsi at marun.edu.tr> on 05/10/2001 05:54:41 AM cc: Subject: [mg28736] [mg28694] Plotting Hi, I have a question regarding the plot. Suppose that you have two separate functions and you would like to plot them on the same graph. Both are not so scaled to plot it using the single y axis. Sometimes we need to draw the plots of two functions (f1 and f2) on two separate y axis (one is on the left as usual and the other on the right). This features are common even very primitive versions of the graph programs such as grapher and excel. I am not able to figure out how to do this in Mathematica. Thanks for your replies in advance. Uður Assoc. Prof. Dr. Uður Yahþi Marmara University Faculty of Arts and Sciences Physica Department, 81040 Goztepe, Istanbul-TURKEY yahsi at marun.edu.tr ************************************************************************************************************************************** All Autoliv e-mails remain Company property and shall be used for business-related purposes only. Do not forward any material contained within this e-mail without prior, written permission from the author's manager. Autoliv disclaims all responsibility and accepts no liability (including negligence) for the consequences for any person acting, or refraining from acting on this information prior to the receipt by those persons of subsequent written confirmation. **************************************************************************************************************************************