Vriety of Coordinate Systems for Graphics
fx-9860GII and fxCG20/10
- Casio Basic provides variety of coordinate systems; Device Coordinate System and Logical Coordinate Systems.
- Device Coordinate System directly corresponds to pixeles of LCD. Left top pixel is pointed by cordinate (1,1) which means (first Row, first Column). Row is in vertical direction and only discrete (natural) number 1, 2, 3, ... is avaiable. Column is in horizontal direction and also only discrete (natural) number is available. With fx-9860GII maximum Row coordinante value is 63 and maximum Column coordinate value is 127. With fx-CG20 max Row value is 187 and max Column vaue is 379. Out of the min - max range or fractional number is set as parameter, Casio Basic returns ERROR.
- Device Coordinate System is automatically applied only at usage of Text, PlxOn, PxlOff, PxlChg and PixlTest commands. User cannot expressly set Device Coordinate System.
- There are 2 deferent ways to setup Logical Coordinate System, a Default Logical Coordinate System and ViewWindow Logical Coordinate System.
- UNDOCUMENTED Default Logical Coordinate System is automatically chosen when ClrGraph command runs. This coordinate system can be expressed by Xmin = -6.3, Xmax = 6.3, Xscl = 0.1, Ymin = -3.1, Ymax = 3.1 and Yscl = 0.1, where those 6 variables are automatically set with those above values. In stead of ClrGraph, following codes gives same resut; Cls:-6.3->Xmin:6.3->Xmax:-3.1->Ymin:3.1->Ymax (where -> is substitution command).
- Using ViewWindow command any coordinate system can be defined freely. We call this here as ViewWindow Coordinate System. In stead of ViewWindow command, setting 6 variables (Xmin, Xmax, Xscl, Ymin, Ymax and Yscl) results in same setup;
See also: ClrGraph, ViewWindow, Xmin, Xmax, Xscl, Ymin, Ymax, Yscl