I’m trying to compare some strings for some custom symbol in a conditional test. Unfortunately I don’t get it to work.
179 0 A CWT C
-170 15 A CNT B
-160 0 D CET C
-170 -15 A CST C
I need to test the third, fourth and fifth column.
When looking at 18.2.6 Text Substitution in the CookBook I find:
However, you can also obtain the entire string from your input file via a single symbol variable $t that must be declared with type s (string). The string will be taken as all trialing text in your data record. To select a single word from the trailing text you just use $tk , where k starts at 0 for the first word, regardless of how many numerical columns that precede it.
In my understanding this means $t = A CWT C for the first entry and I can access it the following way:
$t0 = A
$t1 = CWT
$t2 = C
When I look in 18.2.8 Conditional statements string comparison is possible:
For text comparison note that case will be considered, so “A” does not equal “a”.
My bare bones custom symbol is
N: 1 s
if $t0 == A then {
0 0 1 c -W2p,red
} else {
0 0 1 c -W2p,green
}
but all I get is an error message instead of three red rings and a green one.
plot [ERROR]: Unrecognized symbol code (123 = '{') passed to gmt_draw_custom_symbol
I’m sure I’m making a mistake somewhere. And I haven’t even started to compare for $t1 … Would you kindly nudge me in the right direction? Thank you!
The script to play along:
#!/usr/bin/env bash
cat > location.txt << EOF
179 0 A CWT C
-170 15 A CNT B
-160 0 D CET C
-170 -15 A CST C
EOF
cat > ifelse.def << EOF
N: 1 s
if $t0 == A then {
0 0 1 c -W2p,red
} else {
0 0 1 c -W2p,green
}
EOF
gmt begin if_else pdf
gmt coast -R0/360/-70/70 -JM17c -BWESN -Bxa40f20 -Bya20f20 -Dc -A5000 -Saliceblue -W0.75p,grey
gmt plot location.txt -Skifelse/1c
gmt end show