Project

General

Profile

Bug #9258

Determine output units

Added by Nicolas Ponieman over 4 years ago.

Status:
New
Priority:
Normal
Assignee:
-
Start date:
06/22/2015
Due date:
06/26/2015
% Done:

0%

Estimated time:
Duration: 5

Description

After the last modification in the code, I found a few inconsistencies in the units of the output.
As can be seen here: https://cdcvs.fnal.gov/redmine/projects/qss/wiki/Meeting_March_13_2015
The radius of the analytical solution is ~38.085 mm whereas the period is ~0.799 ns
By getting the max and min values for the x and y columns, we get the distance units is mm as specified in the Session.hh file:
cat output.txt | cut -f 1 | sort -n | head -3
-38.085250000000002
-38.085250000000002
-38.085250000000002
cat output.txt | cut -f 1 | sort -rn | head -3
38.085250000000002
38.085250000000002
38.085250000000002

cat output.txt | cut -f 2 | sort -n | head -3
-76.170490000000001
-76.170490000000001
-76.170490000000001
cat output.txt | cut -f 2 | sort -rn | head -3
0.000000000003288
0.000000000002878
0.000000000002469

However, when we take a look at the period (fourth column represents the time):
cat output.txt | grep "38.0825" | head -5
38.082540000000002 -37.631090000000000 0.000000000000000 0.001982354000000 0.001982354000000 0.000088631710000
38.082520000000002 -38.541069999999998 0.000000000000000 0.002012738000000 0.002012738000000 0.000089990220000
-38.082540000000002 -38.539400000000001 0.000000000000000 0.005977390000000 0.005977390000000 0.000267251100000
-38.082520000000002 -37.629420000000003 0.000000000000000 0.006007775000000 0.006007775000000 0.000268609700000
38.082540000000002 -37.631090000000000 0.000000000000000 0.009972426000000 0.009972426000000 0.000445870600000

We obtain T = 0.009972426 - 0.001982354 = 0.007990
As said before, analytical T is 0.799 ns

According to Session.hh the units should in fact be ns, but we can see here the units are more like ns*100

Moreover, the simulation used to work until t = 66.8 ms, more than 10^6 periods, whereas now it only simulates until t = 0.0667, slightly less than 10 periods.



Also available in: Atom PDF