Useful QDP Commands

A few, commonly used QDP/PLT commands are given below; the full descriptions of the PLT commands is in the ``QDP/PLT User's Guide" or can be listed on the terminal typing ? or help from the PLT prompt.

• Rescaling: to rescale X and Y axes use:

  PLT> r x xlow xhigh
  PLT> r y ylow yhigh
  PLT> r xlow xhigh ylow yhigh

• Logaritmic_Axes: to make the x and/or y axes logarithmic (to the base 10) use:

  PLT> log x
  PLT> log y

• To turn off the logarithmic axes use

  PLT> log off

• Device: to change the current plot device use:

  PLT> dev /xxx

  where /xxx is the new plot device.

• Modelling and Fitting: to use the fitting capability of QDP/PLT two are the main commands MOdel and FIT. The MOdel command is used to define the model, any combination of model components can be added together. For example:

  PLT> mo cons linr quad

  will add a constant, a linear and a quadratic term. The list of the available models is given typing:

  PLT> mo ?

  The Fit command cause PLT to call the fitting routine to search for the best fitting parameters for the model specified with the MOdel command.

• Hardcopy: a hardcopy of the current plot is obtained using:

  PLT> hardcopy filename

  The file is in postscript.

• EXit: to exit from the PLT subroutine type:

  PLT> exit