These all of functions are one of PPL options.
(1) AXLSZE: axis label size
yes? use levitus_climatology
yes? fill/@t temp[k=1]
yes? ppl axlsze 0.19,0.19
yes? ppl fill
Yi at Jeju Island (NIMS, Korea)
yidongwonyi@gmail.com
These all of functions are one of PPL options.
(1) AXLSZE: axis label size
yes? use levitus_climatology
yes? fill/@t temp[k=1]
yes? ppl axlsze 0.19,0.19
yes? ppl fill
Yi at Jeju Island (NIMS, Korea) 
XFOR or YFOR (X label format)
my example,
yes? yes? use levitus_climatology
yes? yes? fill/hlim=120e:135e:2/vlim=30n:50n:5 temp[k=1]
yes? ppl xfor (i3,”^oE”) !”E” as an unit for X axis
yes? ppl yfor (i3,”^oN”) !”N” as an unit for Y axis
yes? ppl fill
yes? go land
———————————————-
http://ferret.pmel.noaa.gov/Ferret/documentation/users-guide/appendix-b-pplus-guide/COMMAND-
Appendix B Sec9.91
XFOR,frmt
Sets the format for the x axis label.
frmt = 0 or (a Fortran format specifier) default=0 (auto label)
Starting with Ferret v6.0 there is an option to label with degrees, minutes and optionally, seconds, rather than the default of degrees.decimal_degrees:
XFOR (dm) for degrees,minutes
XFOR (dms) for degrees,minutes,seconds
To create an integer numeric label the format must begin as “(I” or “(i”. A latitude or longitude axis can be created by specifying ”LAT”), ”LON”), ”LONE”) or ”LONW”) in the format, where the punctuation surrounding LAT, LATW, etc is two single quotation marks. The single quotes are required because PPLUS symbol substitution will occur with 1 single quote. The hemisphere designation will be inserted. Longitude must be continuous across the dateline with west positive for ”LON” or ”LONW”, i.e., 135 is 135W and 190 is 170E. For ”LONE” longitude is continuous across the dateline with east positive, i.e., 135 is 135E and 190 is 170W.
Example:
yes? use coads_climatology
yes? SHADE/L=1/SET sst
yes? PPL XFOR (i5, ”LONW”)
yes? PPL shade
! To label a longitude axis with degrees, minutes use XFOR (DM)
yes? USE my_detailed_data.nc
yes? FILL/SET/x=120:123/y=20:22 var
yes? PPL XFOR (DM)
yes? PPL YFOR (DM)
yes? ppl fill
! or (DMS) may be used to label with seconds as well.