Version 6.7.1 Release Notes

Ferret executables are available for Linux RedHat 5, 32-bit and 64-bit; and for RedHat 6, also 32-bit and 64-bit. The RedHat 6 ones will generally be compatible with linux operating systems such as Ubuntu, Mandriva, etc. There is a note on the main Ferret downloads page about shared-object libraries and Ferret executables.

Ferret v6.7.1 is required for LAS v7.3. Be sure to install the ferret environment as well as the executables, as there is a new color-palette file used by LAS.

Ferret v6.71 is linked with netCDF4.1.2. If you are interested in netCDF4.1.3, you may contact the Ferret developers about test versions of Ferret linked with netCDF4.1.3.

The process for compiling and linking Ferret has been simplified, for those who use operating systems other than the ones for which we release binaries. After the required libraries (NetCDF and HDF) are in place, edit a single file to list the locations of these libraries, and then Ferret is built with a single "make" command. This includes external functions and the fonts files. The file README_build_ferret, in the top-level directory of the source distribution explains the requirements and build process.

New Features

• When a region smaller than a single grid-cell is specified, Ferret will now draw a shade plot (a single color), or a vector plot (a single arrow). Previously regions smaller than a single grid cell resulted in an error message.
• There is a new keyword for creating masks: IFV, indicating ifValid. This is a variation on The IF keyword, in its use for creating masks. (See the documentation about IF and IFV masking.)
  

  ! Standard IF
  yes? LET mask = IF var THEN 1 ! mask is 1 where var is valid and nonzero

  returns FALSE if the value is the missing-data flag, and also if the value is zero. This can cause confusion when there are valid values of zero in the data field. The new IFV syntax,

  ! New IFV
  yes? LET mask = IFV var THEN 1 ! mask is 1 where var is valid

  will make a mask with var treated as valid where it takes the value of zero. There is no change to the IF command for conditional execution, i.e. IF condition THEN commands.

• A new color palette is included, no_white_greenpink_centered. This has bright blues and greens for negative values and bright reds and pinks for positive values, and a neutral color at the center. It's often a good idea to distinguish missing data (white) from values at the central color level (not white). For example,
  

  yes? use coads_climatology
  yes? shade/pal=no_white_greenpink_centered/lev=vc sst[t=15-jan] - sst[t=15-Jun]
  yes? fill/over/pal=no_white_greenpink_centered/lev/nolab  sst[L=1] - sst[L=7]
  yes? go fland 20

  
  
  

Of interest to LAS installers

• Two external functions that Ferret uses when running inside LAS are now linked into the Ferret executable. These are WRITE_WEBROW and LIST_VALUE_XML. (These have no use beyond LAS.)
• The new color palette mentioned above, no_white_greenpink_centered, is now the default palette for color plots of differences between variables in vizGal.

Bug fixes

• A bug was reported dynamic gridding in XY when there are modulo X axes. For some combinations of source grids and destination grids the modulo and regridding operations were done out of order so that the result became garbled. This is fixed.
• For centered variance-based color levels, if there is an open-ended level on one end, there are now always open-ended levels on both ends.
• The family of TAX functions return information about a time axis as formatted strings, such as the date, or month names. These did not return correct results for modulo time axes. This is fixed.
  

  yes? use coads_climatology
  yes? list TAX_DATESTRING(t[gt=sst,L=1:3], t[gt=sst], "day")
  ...
  

  previous output:

   16-JAN      / 1:"16-JAN 06:0"
   15-FEB      / 2:"15-FEB 16:2"
   17-MAR      / 3:"17-MAR 02:5"
  

  new output:

   16-JAN / 1:"16-JAN"
   15-FEB / 2:"15-FEB"
   17-MAR / 3:"17-MAR"