MATHEMATICA IMPORT/EXPORT FORMAT
NASACDF (.cdf)
- Import supports the NASA CDF 3.1 and earlier versions.
- Mathematica by default exports NASA CDF 2.7 files, and can also generate 64-bit enhanced NASA CDF 3.1 files.
- Import["file.cdf"] imports a CDF file, returning the names of the datasets stored in the file.
- Export["file.cdf", expr] exports an array or a Graphics object to a CDF file.
-
- Import["file.cdf"] returns a list of strings representing the names of all datasets contained in the file.
- Export["file.cdf", {expr1, ...}, {"Datasets", {"/dataset1", ...}}] creates a CDF file, storing the arrays or Graphics objects
as separate datasets.
-
- Import["file.cdf", elem] imports the specified element from a CDF file.
- Import["file.cdf", {elem, suba, subb, ...}] imports a subelement.
- Import["file.cdf", {{elem1, elem2, ...}}] imports multiple elements.
- The import format can be specified with Import["file", "NASACDF"] or Import["file", {"NASACDF", elem, ...}].
-
- Export["file.cdf", expr, elem] creates a NASA CDF file by treating expr as specifying element elem.
- Export["file.cdf", {expr1, expr2, ...}, {{elem1, elem2, ...}}] treats each
as specifying the corresponding 
.
- Export["file.cdf", expr, opt1->val1, ...] exports expr with the specified option elements taken to have the specified values.
- Export["file.cdf", {elem1->expr1, elem2->expr2, ...}, "Rules"] uses rules to specify the elements to be exported.
-
- See the reference pages for full general information on Import and Export.
- ImportString and ExportString support the NASA CDF format.
- General Import elements:
-
| "Elements" | list of elements and options available in this file |
| "Rules" | full list of rules for each element and option |
| "Options" | list of rules for options, properties, and settings |
-
- Data representation elements:
-
| "Data" | all datasets imported as a list of arrays |
| "Datasets" | names of all datasets |
- Import by default uses the
element for the CDF format.
- Specifying and selecting datasets:
-
| "Datasets",n |  dataset |
| "Datasets",dataset | named dataset |
- The following values can be given for
:
-
| "Date" | dates, given as DateList specifications |
| "Integer8" | 8-bit integers |
| "Integer16" | 16-bit integers |
| "Integer32" | 32-bit integers |
| "UnsignedInteger8" | unsigned 8-bit integers |
| "UnsignedInteger16" | unsigned 16-bit integers |
| "UnsignedInteger32" | unsigned 32-bit integers |
| "Real32" | IEEE single-precision numbers |
| "Real64" | IEEE double-precision numbers |
| "String" | strings of ASCII characters |
- Meta-information elements:
-
| "Annotations" | meta-information for each dataset |
| "DataEncoding" | specifies how each dataset is compressed |
| "DataFormat" | type used to represent each dataset |
| "Dimensions" | data dimensions of each dataset |
| "Metadata" | general meta-information as a list of rules |
can take the following values:-
| None | no data compression is used |
| "AdaptiveHuffman" | adaptive Huffman encoding |
| "GZIP" | GZIP compression |
| "Huffman" | Huffman encoding |
| "RLE" | run-length encoding |
- Export options:
-
| "Append" | False | whether to append to an existing file |
| "LargeFileSupport" | False | whether to export a 64-bit NASA CDF file |
- With the default setting "LargeFileSupport"->False, the exported file uses a 32-bit data representation conforming to Version 2.7 of the CDF format.
- 64-bit enhanced CDF 3.1 files can be created with "LargeFileSupport"->True.
Get the dataset names:
| Out[1]= |  |
Show the import elements available in the example file:
| Out[1]= |  |
Read all meta-information:
| Out[1]= |  |
Import the 
and 
datasets:
| Out[1]= |  |
Importing the 
dataset returns a date in the form given by DateList:
| Out[1]= |  |
Read a data array from the example file and render it using MatrixPlot:
| Out[1]= |  |
Rasterize the earlier graphics and export them as an array of color values to NASA CDF:
| Out[2]= |  |
Export a list of integers to NASA CDF, explicitly specifying the dataset name:
| Out[1]= |  |
This imports the generated NASA CDF file:
| Out[2]= |  |
New in 6 | Last modified in 8
