The function <#245#>plenv<#245#> is used to define the scales and axes for simple
graphs. <#246#>plenv<#246#> starts a new picture on the next subpage (or a new page
if necessary), and defines the ranges of the variables required. The
routine will also draw a box, axes, and numeric labels if requested.
The syntax for <#247#>plenv<#247#> is:
#ename402#
#eargn405#
#eargn410#
#eargn415#
#eargn421#
Note: Logarithmic axes only affect the appearance of the axes and their
labels, so it is up to the user to compute the logarithms prior to passing
them to <#270#>plenv<#270#> and any of the other routines. Thus, if a graph has a 3-cycle
logarithmic axis from 1 to 1000, we need to set <#271#>xmin<#271#>#math16#= log101 = 0.0,
and <#273#>xmax<#273#>#math17#= log101000 = 3.0.
For greater control over the size of the plots, axis labelling and tick
intervals, more complex graphs should make use of the functions
<#440#>plvpor<#440#> (page #plvpor#441>), <#442#>plwind<#442#> (page #plwind#443>), and <#444#>plbox<#444#> (page #plbox#445>)
described in Chapter #reference#278>.