[GRASS-user] How to draw the earthquake-magtintude map...

[sgw00412 at nifty.com]

Dear grass users

I'm from Japan and begginer user of grass GIS.

I tried to draw earthquake map of tohoku Japan.

First, I summarized of some earthquake data, for example lat, lon, depth and m
agnitude.

---------------------------------
lon     lat    depth Magnitude
---------------------------------
139.9,  37.7,  10,  3.1
141.0,  35.8,  10,  2.6
142.7,  40.8,  20,  4.4
...
---------------------------------

Second, this text data was imported to grass data by using v.in.ascii, as foll
ows;

cat data.txt | v.in.ascii fs=',' cat=0 x=1 y=2 out=quake columns='x double pre
cision, y double precision, depth integer,  mag double precision'

So, I typed to 'v.vect quake'
These points where the earthquake were displayed by cross (x) .

Next, I tried to display new map as circle size of earthquake-magnitude.

v.vect quake size=magnitude

However, unsuccessful....What should I do?

Yasuo shimada ( Japan weathere association )