The routine <#1060#>plbox<#1060#> (page #plbox#1061>) is used to specify whether a frame is drawn around
the viewport and to control the positions of the axis subdivisions and
numeric labels. For our simple graph of the transistor characteristics,
we may wish to draw a frame consisting of lines on all four sides of the
viewport, and to place numeric labels along the bottom and left hand side.
We can also tell PLPLOT to choose a suitable tick interval and
the number of subticks between the major divisions based upon the
data range specified to <#873#>plwind<#873#>. This is done using the following
statement
verbatim8#
Another routine <#1062#>pllab<#1062#> (page #pllab#1063>) provides for text labels for the bottom,
left hand side and top of the viewport. These labels are not clipped,
even though they lie outside the viewport (but they are clipped at the
subpage boundaries). <#877#>pllab<#877#> actually calls the more general routine
<#878#>plmtex<#878#> which can be used for plotting labels at any point relative
to the viewport. For our example, we may use
verbatim9#
Note that 1 and 2 are escape sequences (see page
#escape#881>) which allow
subscripts and superscripts to be used in text. They are described more
fully later in this chapter.
The heights of characters used for the axis and graph labels can be
changed by means of the routine <#1064#>plschr<#1064#> (page #plschr#1065>).