On 5/8/2010 10:25:36 AM, glardner wrote:
...
>I think I was assuming the
>Quickplot function in Mathcad
>to be much cleverer than it
>really is for 3D plotting.
>Once I realised I had to set
>out the ranges explicitly, it
>was straightforward.
>
...
>Regards, and many thanks,
>
>Gerard Lardner
______________________________
The Mathcad QuickPlot works by default the 2D function f(x,y), plot f... on the default ranges x, y � 5 meshed 20. So, a 2D function that does not exist in that range, won't plot and if there is singularity at 0,0 it won't plot . The quickplot is just a quick display in book style that consumes little memory and is very quick. But it does lot more wisely, simple and quick. The quickplot will work the implicit f(x,y) in the scalar form and it will carry all possible and executable scalar maths that can be applied.
In real applied engineering maths, we need more. Like extracting data values that can either be X,Y planes and Z level values. At this point of a project there are several ways of switching from the "scalar maths" mode to discretized mode. The Mathcad "Createmesh" then enters into play. This function is one of the most powerful Mathcad built-in function, simply a two nested for loop. I have the modified version that carries a parameter that belongs to the f(x,y) and thus will spool to file and store the same function as you will modify the parameter (p).
The Mathcad built-in Createmesh is designed to carry an optional rotation parameter for external use. What that means here is that you can design the the 3D solid in all sorts of rotations, store the resulting matrix and plug that in a foreign machine tool. For you to appreciate the rotation(s), visit this forum in the range of less than two weeks, something like "3D rotate". The function in demo is the "Breather", one of the most [if not the most] demonstrative 3D plot that Mathcad renders as perfectly than any other math tool.
That's not all ! There is also the 3D slicer that rotates and extract the two slices in each direction ==> x, ==>y ... export and further process either or both slices [derivative, integrate]. In Mathcad there is limitation but the first limit is the user. Once in hand the matrix level, just plug it in the picture tool for more image processing ... for instance: your steam properties, you can have in a gray scale image. You can extract any pressure (p), temperature (�C) slice ... You can extract the overall matrix for tabulation, from which tabulation you will be able to replot the surface, spline square/rectangular.
All those things are nice and fine, but they don't speak much to the control room operator neither to the plant manager. Those guys sleep in a bed of $$$$$ heavily grounded to earth. They just want 3 meters and 3 columns of data : p, T and enthalpy [per say] and datalog for tracking the plant operation . You could even datalog the images of the hourly operation [per say], plot an RGB cross hair in the region of operation vs another reference cross hair ,,, thus tracking and tracing the life of the plant, no pain no sweat.
Get the 3D rotate, open this one attached.
It will give you a good insight of what Mathcad can do for you.
jmG
