4.4.3.2 Cartesian linear axes

For non-geographic axes, the BASEMAP_TYPE setting is implicitly set to plain. Other than that, cartesian linear axes are very similar to geographic axes. The annotation format may be controlled with the D_FORMAT parameter. By default, it is set to ``%lg'', which is a C language format statement for floating point numbers<sup>4.7</sup>, and with this setting the various axis routines will automatically determine how many decimal points should be used by inspecting the stride settings. If D_FORMAT is set to another format it will be used directly (.e.g, ``%.2lf'' for a fixed, two decimals format). Note that for these axes you may use the unit setting to add a unit string to each annotation (see Figure 4.8).

Figure 4.8: Linear Cartesian projection axis. Long tickmarks accompany annotations, shorter ticks indicate frame interval. The axis label is optional. We used -R0/12/0/1 -JX3/0.4 -Ba4f2g1:Frequency::,%:.