Data Download Help
When you click on the Download Data option on the "Other Operations" page, you will
be guided through a series of forms allowing you to select options for packaging
the data you have been viewing. You may choose data package type, compression
method, parameters by which to subdivide the data and data formatting options.
When you have responded to all the necessary
questions, your data will be packaged per your specifications and available for
download.
The Package Type option allows you to choose whether you would
like your data to end up in one single file or have it divided up into multiple
smaller files as determined by some
user-selected parameters.
For example you might like to
have all data from cruise 99 packaged into one file named cruise99.csv or you
might prefer to have the data divided by station number into multiple smaller
files in directory cruise#99.
dataobject/cruise#99
station#1
station#2
station#3
station#last
Regardless of the package, parameterization and formatting choices,
data are bundled into a single file for downloading.
The Compression option allows you to choose which compression style
you would like to use for this file.
There are four choices:
- zip - recommended for PC and Mac; generates a .zip file which can then be
unpacked with Unzip or MacZip
There are limits on the number and sizes of files that can be transferred with zip
These limits vary among zip implementations. Notably, there is a 4GB size limitation
- tar.Z - UNIX compressed tar file; generates a .tar.Z file; unpack as:
zcat package.tar.Z | tar -xvf -
- tar.gz - UNIX GNU compressed tar file; generates a .tar.gz file; unpack as:
gzcat package.tar.gz | tar -xvf -
- tar - UNIX tar file; generates a .tar file; unpack as:
tar -xvf package.tar
The Parameterization option allows you to select one parameter at each
level on which to divide the data. For example, if level 0 parameters are:
leg, year and month and level 1 parameters are: station, latitude and longitude,
you could choose to divide the dataset into separate files first by leg
(level 0 parameter) and then further by station (level 1 parameter).
You must choose at least one parameter on which to divide the data, but you are
not required to select parameters at all levels. Using the previous example,
you might wish to divide data by longitude only.
Your data can be downloaded in one of several binary or text formats.
The binary formats include
The text format options allow you to separate data fields
by some character and to visually align data in columns
- space-separated, with data visually aligned in columns
- tab-separated, with data visually aligned in columns
- comma-separated, with data visually aligned in columns
- comma-separated but data is not aligned in columns
The default is to generate a space-separated file with column header information, and data visually
aligned in columns, suitable for importing into a spreadsheet program. You may override this by
selecting options from the list above.
Changing the # built into the names of files downloaded with the "multiple small files" option |
WATCH THIS SPACE
The separator character is limited to a letter, a number, a dash or an underscore.
Specifying the file extension for your data file |
WATCH THIS SPACE
Characters in the extension are limited to letters, numbers, dashes and underscores.
Blanks will be turned into underscores.
Naming your package of data files |
The selected Package Name will be used in naming the final bundled
data and documentation files. The
default is to name the file according to the selected data object. If this
works for you, then skip on down. However, there are several other options
for naming the file. For example, if you wish to name the final packaged
file according to one of the parameters by which the data was subdivided,
select that name from the drop-down list. To provide maximum flexibility,
you may also type in a name for your file into the text box. Whichever
method you choose, the appropriate file extension (.zip .tar .tar.Z or .tar.gz)
will be appended to the 'name' specified.
Characters in the name are limited to letters, numbers, dashes and underscores.
Blanks will be turned into underscores.
Some downloads take a long time to prepare. You can start the download
and come back later to pick up the results. If you are going to retrieve
the download from a machine other than the one on which the download
was initiated, it will help if you remember the name of the initiating
computer and/or the id of the downloading process (displayed on the
final download screen). If you want to know when the download is ready
for pickup, you can supply your email address and a message will be sent.
When you return, choose the "download inquiry/data pickup" link.
Information is displayed about downloads initiated from the host where
you are logged on. If none of these downloads is the one in which you
are interested, you can get a list of computers and the most recent
times they initiated downloads. You can use this information to find the
download you'd like to pick up.
Because downloads can be big, they are removed from the "Download and
Other Operations" server after a few days. In such a case, you may see
the name of the download, but no other information or the download itself.
Use your browser's Back button to return to the download form.
Last modified: Jul 16, 2015