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Converts a Scientific Data Set (SDS) in an HDF file to a text file in ArcInfo ASCII Grid format.
| Class: | HDF |
| Intended use: | Recommended for external callers |
| COM: | Exposed as the SDSToArcInfoASCIIGrid method of COM class GeoEco.HDF |
| ArcGIS: | Exposed as the Convert SDS in HDF to ArcInfo ASCII Grid geoprocessing tool |
| Method type: | Classmethod |
| HDF.SDSToArcInfoASCIIGrid( | inputFile, outputFile, sdsName, xLowerLeftCorner, yLowerLeftCorner, cellSize[, nodataValue[, transpose[, mirror[, flip[, swapHemispheres[, overwriteExisting]]]]]]) |
| Python type: | unicode |
| Minimum length: | 1 |
| Maximum length: | 255 |
| Must exist: | Yes |
Input HDF file.
At the time this tool was written, two major versions of HDF were under continuing development: HDF, which was at release 4.2r1, and HDF5, which was at release 5-1.6.5. This tool can process HDF files but not HDF5 files. It can also process HDF-EOS, a specialized version of HDF, but not HDF5-EOS.
For more information on HDF formats, please see http://www.hdfgroup.org.
If you provide a compressed file in a supported compression format, it will be automatically decompressed. If it is an archive (e.g. .zip or .tar), it must contain exactly one file, which must not be in a subdirectory.
| Python type: | unicode |
| Minimum length: | 1 |
| Maximum length: | 255 |
| Must exist: | No |
Output ArcInfo ASCII Grid file.
ArcInfo ASCII Grid format is not formally specified by ESRI but you can find informal specifications by searching the Internet. The format is well-known, stable and very simple. A short example:
ncols 4 nrows 6 xllcorner 0 yllcorner 0 cellsize 50 NODATA_value -9999 -9999 -9999 5 2 -9999 20 100 36 3 8 35 10 32 42 50 6 88 75 27 9 13 5 1 -9999
| Python type: | unicode |
| Minimum length: | 1 |
Name of a Scientific Data Set (SDS) in the HDF file.
If you do not know the name of the SDS, provide your best guess. If an SDS does not exist with that name, a ValueError will be raised. The error message will list the names of all SDSes present in the input file. Select one of these names try again.
You can also use the Extract HDF Header tool to dump the HDF header to a text file. In this file, each SDS will be called a "variable". You can find their names by searching the file for "Variable Name =". For example, the excerpt below from MODIS SST data lists two variables, l3m_data and l3m_qual:
Variable Name = l3m_data
Index = 0
Type= 16-bit unsigned integer
Ref. = 2
Rank = 2
Number of attributes = 4
Dim0: Name=fakeDim0
Size = 4320
Scale Type = number-type not set
Number of attributes = 0
Dim1: Name=fakeDim1
Size = 8640
Scale Type = number-type not set
Number of attributes = 0
Attr0: Name = Scaling
Type = 8-bit signed char
Count= 7
Value = linear\\000
Attr1: Name = Scaling Equation
Type = 8-bit signed char
Count= 47
Value = (Slope*l3m_data) + Intercept = Parameter
value\\000
Attr2: Name = Slope
Type = 32-bit floating point
Count= 1
Value = 0.000717
Attr3: Name = Intercept
Type = 32-bit floating point
Count= 1
Value = -2.000000
Variable Name = l3m_qual
Index = 1
Type= 8-bit unsigned integer
Ref. = 4
Rank = 2
Number of attributes = 1
Dim0: Name=fakeDim2
Size = 4320
Scale Type = number-type not set
Number of attributes = 0
Dim1: Name=fakeDim3
Size = 8640
Scale Type = number-type not set
Number of attributes = 0
Attr0: Name = valid_range
Type = 32-bit signed integer
Count= 2
Value = 0 2| Python type: | float |
X coordinate of the lower-left corner of the raster.
The coordinate is for the corner of the lower-left cell, not the center of that cell. For example, if the raster is a geographic projection of the entire Earth, the coordinate of the lower left corner would be -180.0, corresponding to a longitude of 180 degrees West.
| Python type: | float |
Y coordinate of the lower-left corner of the raster.
The coordinate is for the corner of the lower-left cell, not the center of that cell. For example, if the raster is a geographic projection of the entire Earth, the coordinate of the lower left corner would be -90.0, corresponding to a latitude of 90 degrees South.
| Python type: | float |
Size of each raster cell.
For example, if the raster is a geographic projection of the entire Earth, with 720 columns and 360 rows, it would have a cell size of 0.5, corresponding to 1/2 of a geographic degree.
The underlying data format requires the cells be square. It is not possible to specify a cell size for each dimension.
| Python type: | float or None |
| Default value: | None |
Value that indicates a cell has no data.
| Python type: | bool |
| Default value: | False |
If True, the image will be transposed (flipped about the diagonal axis) prior to conversion. Use this option to fix an image that has the east/west axis going up and down instead of left and right.
| Python type: | bool |
| Default value: | False |
If True, the image will be flipped about the vertical axis prior to conversion. Use this option to fix an image that is the "mirror image" of what it is supposed to be.
| Python type: | bool |
| Default value: | False |
If True, the image will be flipped about the horizontal axis prior to conversion. Use this option to fix an image that is upside-down.
| Python type: | bool |
| Default value: | False |
If True, the east and west hemispheres of the image will be swapped. Use this option to change the orientation of a global image from a 0 to 360 orientation centered on the Pacific ocean to a -180 to +180 orientation centered on the Atlantic ocean, or visa versa.
| Python type: | bool |
| Default value: | False |
If True, the output file will be overwritten, if it exists.
If False, a ValueError will be raised if the output file exists.
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