geographic

set xtics geographic indicates that x-axis values are to be interpreted as a geographic coordinate measured in degrees. Use set xtics format or set format x to specify the appearance of the axis tick labels. The format specifiers for geographic data are as follows:

       %D                   = integer degrees
       %<width.precision>d  = floating point degrees
       %M                   = integer minutes
       %<width.precision>m  = floating point minutes
       %S                   = integer seconds
       %<width.precision>s  = floating point seconds
       %E                   = label with E/W instead of +/-
       %N                   = label with N/S instead of +/-

For example, the command set format x "%Ddeg %5.2mmin %E" will cause x coordinate -1.51 to be labeled as " 1deg 30.60min W".

If the xtics are left in the default state (set xtics numeric) the coordinate will be reported as a decimal number of degrees, and format will be assumed to contain normal numeric format specifiers rather than the special set above.

To output degrees/minutes/seconds in a context other than axis tics, such as placing labels on a map, you can use the relative time format specifiers %tH %tM %tS for strptime. See time_specifiers, strptime.