Invalid annotation phase on exponential axes

[BerginJay]

Description of the problem

When setting the figure frame, the offset (phase) of annotations is invalid on the exponent axes. For example, setting an exponent axis ranging from 0.05 to 1 scaled by the exponent of 0.2, the annotation interval is 0.2, and the phase is 0.1:

gmt basemap -JX10cp0.2 -R0.05/1/0/1 -Bxa0.2+0.1f0.05 -pdf test-exp-phase

We want to annotate it in the positions 0.1, 0.3,..., but this command produces results marked in 0.2, 0.4,..., same with the command without phase:

gmt basemap -JX10cp0.2 -R0.05/1/0/1 -Bxa0.2f0.05 -pdf test-exp

On the contrary, on the linear axes, it produces correct results:

gmt basemap -JX10c -R0.05/1/0/1 -Bxa0.2+0.1f0.05 -pdf test-lin

Full script that generated the error

gmt basemap -JX10cp0.2 -R0.05/1/0/1 -Bxa0.2+0.1f0.05 -pdf test-exp-phase
gmt basemap -JX10cp0.2 -R0.05/1/0/1 -Bxa0.2f0.05 -pdf test-exp
gmt basemap -JX10c -R0.05/1/0/1 -Bxa0.2+0.1f0.05 -pdf test-lin

System information

• Operating system: macOS 13.6.4
• GMT version (gmt --version): 6.5.0