MATLAB Programming

Hierarchical Data Format (HDF4) Files
ReadingaSubsetoftheDatainaDataSet. To read a subset of a data
set, you can use the optional 'index' parameter. The value of the index
parameter is a cell array of three vectors that specify the location in the data
set to start reading, the skip interval (e.g., read every other data item), and
the amount of data to read (e.g., the length along each dimension). In HDF4
terminology, these parameters are called the start, stride, andedge values.
For example, this code
• Starts reading data at the third row, third column ([3 3]).
• Reads every element in the array ([]).
• Reads 10 rows and 2 columns ([10 2]).
subset = hdfread('Example.hdf','Example SDS',...
'Index',{[3 3],[],[10 2 ]})
subset =
7 8
8 9
9 10
10 11
11 12
12 13
13 14
14 15
15 16
16 17
Using the HDF4 Low-Level Functions
This section describes how to use MATLAB functions to access the HDF4
Application Programming Interfaces (APIs). These APIs are libraries of C
routines that you can use to import data from an HDF4 file or export data
from the MATLAB workspace into an HDF4 file. To import or export data, you
must use the functions in the HDF4 API associated with the particular HDF4
data type you are working with. Each API has a particular programming
model, that is, a prescribed way to use the routines to write data sets to
the file. To illustrate this concept, this section describes the programming
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