Rounding of pressure values
Posted: Sun 15 Nov 2020 10:49 pm
I saw the thread back in August when freddie asked about webtag output parameters for rounding (viewtopic.php?f=36&t=18402&p=145783&hil ... es#p145783) and note this is not an easy thing to do due to the number of tags. I would though like to try making an argument for one in particular, and that is pressure.
Although my argument applies more widely, I believe pressure is an extreme case. We currently display pressure in both tables and graphs ("trends") to 2 decimal places. I am sure there is some historic reason for this, but my Davis pressure sensor is quoted with an accuracy of +/-1mb, and I am sure this is fairly common. If we regularly calibrate, then maybe we could achieve a bit better than this, but certainly no better than 0.1mb.
I am worried that any users/recipients/subscribers of this data will come to the conclusion from the incredible precision with which we are quoting pressure values that our pressure accuracy is considerably higher than Davis state. We could (and I do) point out the actual accuracy but then it rather calls into question why we are quoting to 2 decimal places.
If there is a sub-waiting-list for specific output parameters I would like to request that pressure goes on it. Alternatively is there anyone out there that could write a script to take the webtag string, convert to decimal, round it, and convert back to a string? I'm not sure what that would do for the graphs though. Ideally the values should be global.
End of argument!
PS have upgraded to release 3.9.1 and it seems all good so far.
Although my argument applies more widely, I believe pressure is an extreme case. We currently display pressure in both tables and graphs ("trends") to 2 decimal places. I am sure there is some historic reason for this, but my Davis pressure sensor is quoted with an accuracy of +/-1mb, and I am sure this is fairly common. If we regularly calibrate, then maybe we could achieve a bit better than this, but certainly no better than 0.1mb.
I am worried that any users/recipients/subscribers of this data will come to the conclusion from the incredible precision with which we are quoting pressure values that our pressure accuracy is considerably higher than Davis state. We could (and I do) point out the actual accuracy but then it rather calls into question why we are quoting to 2 decimal places.
If there is a sub-waiting-list for specific output parameters I would like to request that pressure goes on it. Alternatively is there anyone out there that could write a script to take the webtag string, convert to decimal, round it, and convert back to a string? I'm not sure what that would do for the graphs though. Ideally the values should be global.
End of argument!
PS have upgraded to release 3.9.1 and it seems all good so far.