Modern mode and default -J

Q&A
1

When I do;

$ gmt pscoast -Bafg -W -RNO -pdf testmap

I assume GMT implicitly goes modern mode since -pdf is given (edit: confirmed after testing). This makes it not necessary for me to specify a projection (-J). So, what -J is chosen for me?

Edit: I thought that I should be able to probe this myself by looking in the ~/.gmt/session/gmt6.[ppid], but it’s just to fast gone (if it even exists…?)! Is it any way I can see the equivalent of gmt.history (and gmt.conf) for a modern mode plot?

Discard rest of post below. Keeping for possibly future use.

PS! Any way to use strikethrough in this forum?

Dir now looks like this:

$ ls
testmap.pdf

Run the command again, but remove -pdf testmap, and GMT goes classic;

$ gmt pscoast -Bafg -W -RNO
pscoast [ERROR]: Must specify a map projection with the -J option

Since now in classic mode gmt.history is created. The dir now looks like this:

$ ls
gmt.history  testmap.pdf
2

Add -Vd to your command and you’ll see

gmt [DEBUG]: Modern: Adding -JQ15c+ to options since there is no history available.

BTW, the forum uses markdown syntax. So you can have strikethrough by

~~any words here~~

any words here

3

Great seisman, thanks.

4

Alright, and now part deux.

#Modern mode - auto -J, plots fine
$ gmt pscoast -Bafg -W -ENO -pdf testmap

# Invoke classic mode - gmt.history written
$ gmt pscoast -Bafg -W -ENO 
pscoast [NOTICE]: Computed primary annotation font size: 6.66667 p  Dimension scaling: 0.666667
pscoast [ERROR]: Must specify a map projection with the -J option

$ ls
gmt.history  testmap.pdf

#Repeat first command
$ gmt pscoast -Bafg -W -ENO -pdf testmap
begin [NOTICE]: Computed primary annotation font size: 6.66667 p  Dimension scaling: 0.666667
coast [NOTICE]: Computed primary annotation font size: 6.66667 p  Dimension scaling: 0.666667
coast [ERROR]: Must specify -R option
end [NOTICE]: Computed primary annotation font size: 6.66667 p  Dimension scaling: 0.666667

When I do the first (modern mode) command again, now with a gmt.history present in the directory, I get the Must specify -R option-error as shown in the last command.

PS! Any way to use tags to do preformatted text instead of padding all code lines with four spaces?

5

PS! Any way to use tags to do preformatted text instead of padding all code lines with four spaces?

You can use triple backticks. See the link for examples:

6

Are you sure?

gmt coast -Bafg -W -ENO -pdf testmap

coast [ERROR]: Must specify -R option

There is no -R, only a selection of NO via -E.

7

Thats strange.

$ gmt coast -Bafg -W -ENO -pdf testmap

works fine and produces a map.