Need Help With Locator in a Manipulate

*To*: mathgroup at smc.vnet.net*Subject*: [mg132261] Need Help With Locator in a Manipulate*From*: Gregory Lypny <gregory.lypny at videotron.ca>*Date*: Sun, 26 Jan 2014 03:14:21 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net

Hello everyone, I'm creating a Manipulate that has two locators. I was able to get the first locator, pt1, working the way I want, but am not sure how to handle the second, pt2. Locator pt1 determines the intersection of two curves, a straight line with slope m and a power function, k[], with shape parameter a. Both m and a can be varied using sliders. I want the second locator, pt2, to be constrained to move along the line determined by locator pt1 and slope m. In a previous post some time ago, Bob Hanlon and John Fultz kindly showed me how to constrain a locator to move around the perimeter of a circle, but this used DynamicModule, and I am not sure how to bring this into a Manipulate. Any guidance would be greatly appreciated. The code for my Manipulate is below. Right now, locator pt2 is arbitrarily set to {50,50} but it doesn't do anything. Manipulate[ Module[{f,b,xmin=0,xmax=100,k}, b=pt1[[2]]-m*pt1[[1]]; k[{x_,y_},a_]:=x^a y^(1-a); Plot[{(k[pt1,a]/x^a)^(1/(1-a)),m x +b},{x,0,100}, AxesOrigin->{0,0}, PlotRange->{Automatic,{0,200}}]], {{a,.5,"Shape (a)"},.2,.8,Appearance->"Labeled"}, {{m,-1,"Slope (m)"},-3,-.4,Appearance->"Labeled"}, {{pt1,{10,80}},Locator}, {{pt2,{50,50}},Locator}] Regards, Gregory Lypny

**Follow-Ups**:**Re: Need Help With Locator in a Manipulate***From:*Gregory Lypny <gregory.lypny@videotron.ca>

**Re: Need Help With Locator in a Manipulate***From:*Bob Hanlon <hanlonr357@gmail.com>

**Re: Need Help With Locator in a Manipulate***From:*Gregory Lypny <gregory.lypny@videotron.ca>

**Re: Need Help With Locator in a Manipulate***From:*Bob Hanlon <hanlonr357@gmail.com>

**Re: Need Help With Locator in a Manipulate***From:*Gregory Lypny <gregory.lypny@videotron.ca>