Minor tic marks along the x axis are controlled by mxtics. They can be turned off with mxtics. Similar commands control minor tics along the other axes.
Syntax:
set mxtics {<freq> | default} unset mxtics show mxtics
The same syntax applies to mytics, mztics, mx2tics, my2tics and `mcbtics`.
<freq> is the number of sub-intervals (NOT the number of minor tics) between major tics (the default for a linear axis is either two or five depending on the major tics, so there are one or four minor tics between major tics). Selecting `default` will return the number of minor ticks to its default value.
If the axis is logarithmic, the number of sub-intervals will be set to a reasonable number by default (based upon the length of a decade). This will be overridden if <freq> is given. However the usual minor tics (2, 3, ..., 8, 9 between 1 and 10, for example) are obtained by setting <freq> to 10, even though there are but nine sub-intervals.
Minor tics can be used only with uniformly spaced major tics. Since major tics can be placed arbitrarily by `set {x|x2|y|y2|z}tics`, minor tics cannot be used if major tics are explicitly `set`.
By default, minor tics are off for linear axes and on for logarithmic axes. They inherit the settings for `axis|border` and `{no}mirror` specified for the major tics. Please see xtics for information about these.