refid and decimate with Python gxapi/gxpy

DavidHoward

Newbie looking for some howto help with refidding and decimating channels. Basic script is below. Thanks.

##import geosoft.gxpy as gxpy ##import geosoft.gxpy.project as gxprj ##import geosoft.gxpy.utility as gxu import geosoft.gxpy.gdb as gxdb ##import geosoft.gxapi as gxapi ##import geosoft.gxpy.vv as gxvv ##import geosoft.gxapi.GXDU as gxdu import numpy as np #https://geosoftgxdev.atlassian.net/wiki/spaces/GXD93/pages/103415898/Geosoft+Databases ##gxc = gxpy.gx.GXpy() def rungx(): # open the database with gxdb.Geosoft_gdb.open() as gdb: newdbName = str(gdb).replace('.gdb','_refid.gdb') #create a new database for refid data with annotated channel names new_db = gxdb.Geosoft_gdb.new(newdbName, overwrite=True) ## for channel in gdb.list_channels(): new_channel = gxdb.Channel.new(new_db, channel + '_r') # get a list of selected lines lines = gdb.list_lines() # work through each line for line in gdb.list_lines(): print ('processing line {}'.format(line)) #read each channel as a vv, refid and write to new db for channel in gdb.list_channels(): myVvData = gdb.read_channel_vv(line, channel) #refid the data -- HOW? ************************** ## gxvv.GXvv.refid(myVvData, (0,1), myVvData.length) #this doesn't work #decimate the data -- HOW? ************************** ## gxapi.GXVVU.decimate(myVvData, 10) new_db.write_channel_vv(line, channel + '_r', myVvData) input("Press return to continue...") exit()

BeckyBodger

Hi @DavidHoward I’m going to move your discussion over to The GX Developer Forum. It’s the more appropriate place for python questions and where other developers are more likely to see your questions.

JacquesBeaurain

Hi @DavidHoward,

The refid method is not a static method and needs to be called as follows:

myVvData.refid((0,1), myVvData.length)

Jacques

IanMacLeod

@DavidHoward

The gxvv.GXvv.refid() can be used to decimate by multiplying the fid separation by your decimation. Something like this should work:

myVvData = gdb.read_channel_vv(line, channel) start, separation = myVVData.fid myVvdata.refid((start, separation * 10), myVvData.length // 10) new_db.write_channel_vv(line, channel + '_r', myVvData)

DavidHoward

Thanks, all. Both work a treat. Easy when you know how.
(Sorry about the Geonet tag. I thought I'd selected the GX Developer tag but missed.)