The development version (I wouldn't even venture to call this an alpha version) of CurveExpert 2 is available for download from this web page. Be forewarned...documentation is almost nonexistant (although there are some useful examples of user models currently in the help file) and expect the software to crash! It is very unfinished, although I do believe the computational engine to be correct and functional. The user models should work also -- look in the help file for some documentation on what you can do with them, and also some examples. My tests indicate that the new user model parser is 7-10 times faster than the one in CE 1.3, which means a big savings in time for those of you using the user (custom) model features.
Obviously, the development copy should not be distributed to anyone, under any circumstance!To download, click here [updated: 10/28/98]. Please read the text below!
The user interface that I am shooting for is this: envision a desk (workspace) at which one is trying to work with a dataset and various ways to analyze it. The user would have the raw data [the Data window], raw results [the Results window], drawings of those results [the Visualization window], and some scribbled notes [the Documentation window]. CurveExpert attempts to simulate this situation by providing each of these in a workspace-like environment. Eventually, there will be one menu corresponding to each window...the Data menu operates on the Data window, the Analyze menu operates on the Results window, and the Visualize menu operates on the visualization window. The other menus are general-purpose.
Since the multivariate regression is supposed to work (although it has not been validated by any means), it deserves a quick word of explanation. An example will probably provide the best teacher; the following is a valid user model:
parameter a,b,c
parameter d
mytemp = 32.3*x2
myresult := mytemp*a*x1 + b*x2 + exp(c*x3) + d*x4^2*sin(x3)
in short: declare parameters with the "parameter" statement at the beginning of the user model routine. You can use temporary variables by using a simple assignment statement with the "=" sign. The result (dependent variable) is always on the left hand side of the ":=" sign. As you have probably noticed, the independent variables are specified by x1, x2, and so on. The dependent variable can be called anything you like, except for a reserved word (like x1, x2, sin, cos, etc). Also, the variable "x" is a synonym for "x1" for convenience.
Now for the data import...use the "File->Import" command to get your data into the document. Right now, editing the built-in spreadsheet from scratch will have no affect (you can edit data that has been imported, however). If you want to save a native CurveExpert document and later restore it, it should work by choosing "File->Open" and "File->Save".
I know that the four initial windows are very irritating to work with right now...use the "Window->Tile" command to help out. I plan to save these window positions with the document and when the applications shuts down, so the user can put these where he/she wants them, and they will stay put thereafter.
The "Documentation" window is for the user to type anything that they desire, and it will saved along with the document. To format the text (like a word processor), you have to select "View->Toolbar->Formatting" to be able to change the size, font, etc. of the text.
You will need the OpenGL libraries installed on your system for this version of CurveExpert to run! If you are a Windows NT user, no problem. If you are a Win95 user, there is a chance that these libraries are not installed. If not, you can download them from Microsoft by clicking this.
Tidbits:
Any suggestions are welcomed.
A point that bears repeating...this software is unfinished; there will be many, many places where the program will not behave as you expect it to.
Enjoy!
Updated: 9/15/98