The ZStandard Command

Command Summary

Restores window settings to the default.

Command Syntax


Menu Location


  1. ZOOM to access the zoom menu.
  2. 6 to select ZStandard, or use arrows and ENTER.

Calculator Compatibility


Token Size

1 byte

The ZStandard command resets all window variables found in the Window screen to their default values. This means that, unlike the other zoom commands, ZStandard can affect variables other than Xmin, Xmax, Ymin, and Ymax. However, it will only affect variables that have a purpose in the current graphing mode. Here are the default values set by ZStandard:

In all modes:

  • Xmin=-10
  • Xmax=10
  • Xscl=1
  • Ymin=-10
  • Ymax=10
  • Yscl=1

Only in Func mode:

  • Xres=1

Only in Param mode:

  • Tmin=0
  • Tmax=2π (in Radian mode) or 360 (in Degree mode)
  • Tstep=π/24 (in Radian mode) or 7.5 (in Degree mode)

Only in Polar mode:

  • θmin=0
  • θmax=2π (in Radian mode) or 360 (in Degree mode)
  • θstep=π/24 (in Radian mode) or 7.5 (in Degree mode)

Only in Seq mode:

  • nMin=1
  • nMax=10
  • PlotStart=1
  • PlotStep=1

These settings are often useful as a "lowest common denominator" that will work fairly well for all graphs.

Advanced Uses

ZStandard is often used before commands such as ZSquare or ZInteger in programs. This serves two purposes: it makes sure that the center of the screen for ZSquare and ZInteger is (0,0), and it ensures that the graph screen is cleared without having to resort to ClrDraw (because with two different zooms in a row, the window settings have to change at least once, which means the graph will have to be regraphed)

Error Conditions

  • ERR:INVALID occurs if this command is used outside a program.

Related Commands


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