The Zoom commands are found in the menu you get by pressing ZOOM. They are used to manipulate the window variables to change the bounds of the graphing window. With the exception of ZStandard, ZoomSto, and ZoomRcl, these commands only affect the variables universal to all graphing modes: Xmin, Xmax, Xscl, Ymin, Ymax, and Yscl. They ignore the variables specific to a single graphing mode:
- Xres (only used in Func mode)
- Tmin, Tmax, and Tstep (only used in Param mode)
- θmin, θmax, and θstep (only used in Polar mode)
- nMin, nMax, PlotStart, and PlotStep (only used in Seq mode)
Virtually every window variable has a z-equivalent (ZXmin for Xmin, ZPlotStart for PlotStart, etc.) that are found under VARS|2:Zoom… — these are used by ZoomSto and ZoomRcl. Also, the variables XFact and YFact (found under VARS|1:Window…) are used by Zoom In and Zoom Out.
The commands themselves are only available in programs. Outside it, you can only choose the equivalent menu option (which doesn't leave an entry on the homescreen, and sometimes slightly differs in effect) — this happens, even if you choose the command from the catalog. Of course, with a bit of trickery, you can get the command token itself on the homescreen, but then ERR:INVALID will be thrown if you try to use it. The Trace command also works this way.
The following zoom commands are available: