The first thing you should do is
write a CDL file describing your
data. You can use the ncgen utility
to check the correctness of that
CDL description.
Further, you should use netcdf-4
and not the more limiting netcdf-3.
Now, here is my first try at answering
your question:
1. How do I store the patientâs name? Is that possible?
You can store a name as a variable of type String.
2. Iâve mapped every patient to a NetCDF dimension. To retrieve a
patientâs data I need to map the patient to its dimension. Can this
information be kept on NetCDF or do I need to store this mapping on a
database outside NetCDF? For instance, John Doe is mapped to dimension
25 (my 25th patient) on the data.
One simple way to do this is to define a variable like this:
dimensions:
numberofpatients=2000;
variables:
String names(numberofpatients);
Then you can search the names variable for a matching patient name.
The index of names at which you find the matching name then
becomes the index of the patient.
3. I use time as an unlimited dimension, with time 0, as the first day
of the program. When a new patient enters the program, we do not have
any data for her yet. Letâs say that she enters the program after 100
days, if we use a time index of 100 NetCDF will create empty slots for time
0 to 99 for this patient and if I understand correctly, this will waist
space. Is that the right way to do this?
netcdf-3 will waste this space. If you use netcdf-4
(as I recommend), then the space is managed more efficiently
internally and no space is wasted.
4. On the same line of question 3, when I stop collecting ânormal dataâ
to collect âtreatment dataâ, there will be a gap on the data. For
instance, letâs say that I stop collecting normal data on day 100 and
resume it on day 150, will there be a gap of 50 days with empty records
from day 100 to day 149?
Same answer as #3. But I would not worry about the wasted space
unless you really think your data will have a really large
number of records. The space is wasted on the disk (with netcdf-3)
but does not affect memory usage.
=Dennis Heimbigner
Unidata
=Dennis Heimbigner
Unidata
Ticket Details
===================
Ticket ID: FQQ-870725
Department: Support netCDF
Priority: High
Status: Closed
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