Next: Preface to version 3.1
Up: Preface to version 3.2
Previous: Major bug fixes in
We have added many new and significant features in this version.
Many of these have long been anticipated by the user community:
- Paper Media Selection:
- We have added support for paper media formats in .gmtdefaults.
PAPER_WIDTH have been replaced by PAPER_MEDIA which can be set
to one of
30 different media like A4, Letter, Legal, etc.
Append - for Manual Feed, and + for EPS file format.
Usage is discussed in the gmtdefaults man and web pages.
- Pattern Files:
- Programs reading rasters can now read Run Length Encoded Sun rasterfiles.
gmthex2ras.c is obsolete since Sun rasters are supposed to be
read/written at the 1-byte level, thus avoiding big/little endian troubles
(this was what gmthex2ras.c was supposed to deal with).
- Explicit Unit Specification:
- All options that specifies lengths or sizes can now have a unit-modifier
appended that explicitly sets the length unit. This allows users to write
unit-independent GMT scripts that will function correctly regardless of
what the MEASURE_UNIT parameter is set to. E.g., -JM6 can give a map that
is 6 cm, 6 inches, or 6 meters wide depending on MEASURE_UNIT, while
-JM6i will always give a 6 inch map. The unit-modifiers allowed are
c (cm), i (inch), m (meter), and p (point).
All GMT example scripts have been edited to use this mechanism.
A related issue is that all internal GMT functions expects pens to be
in points, not dpi units. You may still specify pens in dpi units, but
GMT will convert to points and update .gmtdefaults using points.
- Absolute Positioning with -X -Y:
- By prepending ``a'' to the x and y offsets you can now get
absolute rather than the [default] relative shifts of coordinate origin.
For example, -Xa4i -Ya4i will temporarily move the origin (4,4) inches,
then reset to (0,0) after plotting.
[Default leaves the origin at (4,4), and subsequent -X -Y are now relative
to that origin, not the original (0,0).
- New Geospatial Filtering Option:
- gmtselect has new switch -N for checking if points are inside/outside
geographical features (coastlines, so one may also set -A -D as in
pscoast and grdlandmask ).
- New RPN Calculator for Table Data:
- The new program gmtmath is a ``Reverse Polish Notation'' calculator that will
create or operate on table data; it thus complements grdmath .
It is much simpler and faster than awk for calculations on tables.
- New Operators for gmtmath (23) and grdmath (26):
- New functions include KEI, KER, BEI, BER (Kelvin-Bessel functions
or order 0), LOG1P, POP (delete stack entry), PLM
(Associated Legendre polynomials), I0, I1, IN, K0, K1, KN (modified
Bessel functions), ERF and ERCF (error functions), YLM
(fully normalized surface spherical harmonics), and STEP (Heaviside
step function). In addition, you can use the
Bessel functions J0, J1, JN, Y0, Y1, YN if your system supports them
(The gmt_math_init script(s) will find out and add them to gmt_math.h). Finally, in grdmath we have added the
operators DDX (
), DDY (
), D2DX2 (
), D2DY2
(
), and CURV (
), and in
gmtmath we have DDT (d/dt) and D2DT2
(d2/d t2).
- ZapfDingbats added to GMT Fonts:
- Since it is present in most modern PostScript laserwriters we have
added ZapfDingbats to the list of build-in GMT fonts, making
a total of 35 fonts. Appendix F shows the new symbols.
- Binary i/o with -M:
- If the -M and -b options are used together, GMT will look for
multisegment headers in binary files which are defined as records where all
fields equal NaN. Any flags passed to -M are ignored.
- Improved makecpt and grd2cpt :
- These programs now have built-in knowledge of about a dozen or so standard
color tables that the user may choose from. You can also use an existing
cpt file as the starting point. It is now simpler than ever to make
various color tables other than the default rainbow map.
- All Documentation in both PostScript and HTML Format:
- All GMT documentation (including the toturial) have been rewritten in
LATEX, thus facilitating translations to PostScript and HTML
web pages with GIF illustrations. For the first time, the documentation
comes with an index, and has undergone modest changes in contents.
The main enhancements to the GMT command line options are listed in
Table 1.6.
Table 1.6:
New capabilities in GMT 3.2
Program |
Changes |
gmtselect |
-–N (and -–A, -–D) for geospatial search using coastlines |
grdcontour |
Appending p to the -–Z option allows for periodic z-data |
mapproject |
-–D to temporarily reset MEASURE_UNIT |
psscale |
Will read standard input if -–C is not set |
pstext |
-–W takes optional pen after o |
triangulate |
-–D will take derivative in x- or y-direction |
|
The main backward incompatibility introduced by GMT 3.2 is related
to the big improvements in makecpt . These are outlined
in Table 1.7, revise any GMT shell scripts accordingly.
Table 1.7:
Incompatibilities between GMT verions 3.1 and 3.2
Program |
Changes |
makecpt |
-–C now takes the name of a master color palette table. |
|
Old -–C, -–M, and -–S have been replaced by -T. |
pslib |
Programmers linking their programs with pslib should look at |
|
the man page and examine the small change to ps_plotinit. |
|
For more details see the CHANGES file.
Because all documentation has changed completely,
while coastlines have not, and the source code is pretty
small anywat, there are no patch files. You must reinstall
the entire package, except you do not need to copy the
*_lib.tar file or the
optional high and full-resolution coastlines since they
have not changed.
New users should simply get the latest install_gmt
script which will get the most recent tar files of all the packages.
Next: Preface to version 3.1
Up: Preface to version 3.2
Previous: Major bug fixes in
Paul Wessel
1999-07-01