Plus signs where longitude and latitude lines should be

Hello all. I’m a new user of GMT with very little programming experience but have been running Linux for 12 years. I have an interest in maps, of course.

For whatever reasons when executing the following code…
pscoast -Rg -JG-75/41/4.5i -B15g15 -Dc -A5000 -Gblack -P >

…the lines of longitude and latitude are represented by a plus sign (+). Do you know how I can fix this?

I’m running Ubuntu 18.04 Mate with GMT 5.4.3

Thank you,

Peter Dutton

If you are a new user of GMT you should definitively have started with GMT6. Regarding your question, you probably have some .gmtdefaults file trailing around with a setting to plot crosses instead of grid lines. See the man page of gmtdefaults (I think), or gmt.conf in GMT6.

GMT 6…well installation looks like a nightmare of difficulty for us simple folks.

GMT.conf is also for version 5.4.3

I’m thinking that the lat/long continuous lines are set by GRID_CROSS_SIZE_PRIMARY and SECONDARY

I’ll give it a try but I’m sure I’ll mess it up.

Should not be any harder than GMT5 :slight_smile:

But tell us, what did find so scaring in the installing instructions? (aside from the fact that infinite number of Linux distros lead to long list of choices)

Ubuntu still only doing GMT 5.


GMT 6.0.0 came out in Sept/October so it is only 7 months ago. It would be nice if they were not always so far behind but that is life on Ubuntu.

Yes, gentlemen…only version 5.4.3 is in Ubuntu 18.04 repository (Synaptic Manager).

But, Joaquim, to answer your question about the difficulty of installing GMT 6.

You’re most likely way, way, way more advanced in Linux than I ever will be. Looking at the instructions for “building GMT 6” (since Ubuntu 18.04 installs v. 5) it’s recommended to “build” GMT. That’s way too complex for me to follow as too many dependencies and too many possible ways to wreck the installation.

However, I did see something called “homebrew” here-

Supposedly that’ll make installing v 6 easier. I’ll write back with the results.

Results- it was a flop as Homebrew doesn’t support 32 bit installations (mine plus a few vacuum tubes).

Thank you,

Peter Dutton

To tell you a secrete, I can’t stand unix machines for more than 30 minutes. I’m a happy Windows user. But I do build GMT in those tortuous systems time to time.

Homebrew is for Macs but there is a Linuxbrew as well and it should be a very interesting alternative, though I don’t know about 32 bits availability, but why not?

Don’t be scared by the long building instructions. For ubuntu users, you can install all the dependencies using following commands:

# Install required dependencies
sudo apt-get install build-essential cmake libcurl4-gnutls-dev libnetcdf-dev

# Install optional dependencies
sudo apt-get install gdal-bin libgdal-dev libfftw3-dev libpcre3-dev liblapack-dev libblas-dev libglib2.0-dev ghostscript

# to enable movie-making
sudo apt-get install graphicsmagick ffmpeg

# to enable document viewing via gmt docs
sudo apt-get install xdg-utils

If you set MAP_GRID_CROSS_SIZE_PRIMARY and MAP_GRID_CROSS_SIZE_SECONDARY to 0p in your gmt.conf file, that should give you continuous lines as usual.

As an aside, the latest Ubuntu LTS 20.04 Focal Fossa does have GMT 6, see Ubuntu – Details of package gmt in focal.