Frequently Asked Questions | ||||||

If I get repeated questions, I'll post the questions and responses here

*Q1: I'm having some problems coming up with an equation for my 3d mesh/surface plot. Since both cost and deflection can be defined separately in terms of thickness, i am trying to formulate an equation for thickness in terms of cost and deflection. Does this approach sound correct?**Q2: We dont have experience writing an equation in terms of 2 independant variables..any suggestions there?**Q3: You are looking for a mesh/surf type 3d plot right? Not just 3data points (for original, min thickness, and suggested design) floating in 3d space?? Or would that also be acceptable?*

**Q1: I'm having some problems coming up with an equation for my 3d mesh/surface plot. Since both cost and deflection can be defined separately in terms of thickness, i am trying to formulate an equation for thickness in terms of cost and deflection. Does this approach sound correct?**

...it's important to think carefully about these kinds of problems. In terms of formulating an equation, you can make assumptions if you find they are valid (ie can you find some prices that confirm this?) in general in engineering. So the idea of this plot is to generate a figure that tracks the cost vs. these other parameters.

**Q2: We dont have experience writing an equation in terms of 2 independant variables..any suggestions there?**

Regarding 2 independent variables, it's simply a matter of a z that is dependent on x and y (for example, z = x+y or z=x.*sin(y). The trick is that for a mesh there has to be a z for every x and y combination, a grid. And you generate that XY grid with the 'meshgrid' command in matlab. You don't have to have an equal number or range. You need a vector of x's and a vector of y's, then use [X,Y]=meshgrid(x,y); and matlab generates the grid for you. If you have an equation for z, then plugging in X and Y in a for loop allows you to generate a Z point for each XY point. Plotting a 3d line is much easier - just make use of the plot3 command, and you will need equal numbers of points in x,y,and z, rather than a grid of x and y.I think what is making this challenging for you is that

**Q3: You are looking for a mesh/surf type 3d plot right? Not just 3data points (for original, min thickness, and suggested design) floating in 3d space?? Or would that also be acceptable?**

If it makes more sense to you to do a line plot where you find several 3d points and plot a 3d curve, and others for your other designs, etc, you can do that. Whatever you choose just try to justify it with a description in the report, and make sure you satisfy the report requirements document. Plots and numbers are great, but basically should be used to argue for some point.