Re: a simple plotting question

*To*: mathgroup at smc.vnet.net*Subject*: [mg114471] Re: a simple plotting question*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Sun, 5 Dec 2010 21:51:54 -0500 (EST)

On 12/4/10 at 6:14 AM, sahserkan at hotmail.com (martinez) wrote: >How do I plot the following function of two variables? (not 3-d >plot!) >g[y_]=y^3; h[z_]=z^2+8 >f[y_,z_]=g[y]+h[z] >Plot[f[y,z],{y+z,0,3}]?? or >Plot[f[y,z],{x,0,y+z}]?? >I mean the x-axis is devided into two parts, so x is y and z >dependent, so how do I plot it? You have defined a function that maps every point of a plane to a value. This is inherently a 3-D problem and cannot be handled by Plot. If you don't want to use Plot3D, there are other functions such as ContourPlot or DensityPlot which will work for this type of problem. Or, you can fix the value of one of the parameters thereby reducing the problem to a 2-D problem which can be handled by Plot.