 Example 1: XY plot   Whenever you need to see one variable as a function of another, you can use the SIMEQ function plotxy. In the Command Window simply enter: >>plotxy('x-Tagname',    'y-Tagname',     'From',       'To')   e.g. >>plotxy('Z6FreshFeed','Z6GypsumFeed','5-aug-03','15-aug-03') If you look in the upper left corner we have asked to have basic fitting done to the data. We have chosen a linear fit. They show that we have been using 5.5% of gypsum as average, and that we are working with a very small offset of 0.057. This is perfectly Ok. To make the basic fitting, you select the Tools menu and then Basic Fitting. A window like the one below will appear: Here you can select what kind of fitting you want to have inserted on the plot. We have used a linear fit for this example, and then we have chosen to have the equation shown on the plot.   As it can be seen, many different fitting models are included in Basic Fitting. The list continues up to 10th degree polynomial.       The xy plot is normally used to make a quick check that process variables correlate, as they should.               Another typical example is as help to find the best circulation factor for a given cement and mill. Here the xy and curve fitting capabilities are used in a programmatic way, since the raw signals needs a little treatment before they can be used for this purpose. The above shows an optimum performance using 105 t/h rejects from a cement mill. The production is expected to be around 120 t/h. Circulation is then (R+F)/F = 1.88. In the above plot, one blue point is one minute. The red points are the LSQ average. See also xyz plotting.                                                               To the top