I made this figure where I plot columns representing the earthquakes by each 10 km2 (done with gmt blockmean -R$REGION -Sn -C -I10k
).
In the map I use this to plot the columns (6 arc-min):
gmt plot3d -p $OUT -So0.1u -C -i0:2,2 -t50
How can I set the base of the columns to 10 km? I tried -So10k
but I get:
Length <unit> k not supported - revert to default unit [cm]
You need to play with the +b|B modifiers
-Sb [size [c |i |p |q ]][+b |B [base ]][+v |i ny ][+s [gap ]]
I think that +b|B are for the z value of the column.
I want to define the x and y dimensions of the base of the 3d columns.
That is what you defined with the -I of blockmean
Exactly. I want to use that dimension for the columns so I can get a figure similar to the 3-D Histrogram of example 8 .
In that case works, because the grid was 5 arc-minut and them -So0.0833333u
was set for the columns. But, in my case, the grid is in km.
I’m confused now, Since you added the bars on a geog grid the coordinates of those bars are in geogs too and the width = 0.1 which is ~10 km. Or the bars file (the one passed in to plotd3d
) is not in geogs?
My data looks like this (long, lat, number of earthquakes). The log, lat are use to place the bars. I think I need two more columns to define the xsize and ysize (in c,i,p) that would represent 10 km in the map. I first use -I0.1u
that is ca. 10 km.
-69
-33
3
-68.8888888889
-33
6
-68.7777777778
-33
3
-68.6666666667
-33
3
-68.5555555556
-33
1
-68.4444444444
-33
3
-68.3333333333
-33
2
-68.2222222222
-33
1
-68.1111111111
-33
1
-68
-33
2
And doesn’t -So0.1u
give you what you want?
I can live with that. But it is not exactly what I want.
Don’t know if it helps,
I used that in one of my script:
-So$(gmt math -Q 10 KM2DEG -Vq =)
the verbose-quiet because gmt send some warnings about ellipsoids
1 Like
Joaquim
November 7, 2022, 7:26pm
11
That is also an approximation because it’s true only in N-S.