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improved doxygen documenation

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Edward Hartnett 2021-08-26 10:39:27 -06:00
parent 2b3d2c1edf
commit d29436c99d
1 changed files with 41 additions and 2 deletions
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libhdf5/hdf5var.c
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@ -810,10 +810,49 @@ done:
* @internal Set quantization settings on a variable. This is
* called by nc_def_var_quantize().
*
* Quantization allows the user to specify a number of significant
* digits for variables of type ::NC_FLOAT or ::NC_DOUBLE. (Attempting
* to set quantize for other types will result in an ::NC_EINVAL
* error.)
*
* When quantize is turned on, and the number of significant digits
* has been specified, then the netCDF library will apply all zeros or
* all ones (alternating) to bits which are not needed to specify the
* value to the number of significant digits. This will change the
* value of the data, but will make it more compressable.
*
* Quantizing the data does not reduce the size of the data on disk,
* but combining quantize with compression will allow for better
* compression. Since the data values are changed, the use of quantize
* and compression such as deflate constitute lossy compression.
*
* Producers of large datasets may find that using quantize with
* compression will result in significant improvent in the final data
* size.
*
* Variables which use quantize will have added an attribute with name
* ::NC_QUANTIZE_ATT_NAME, which will contain the number of
* significant digits. Users should not delete or change this
* attribute. This is the only record that quantize has been applied
* to the data.
*
* As with the deflate settings, quantize settings may only be
* modified before the first call to nc_enddef(). Once nc_enddef() is
* called for the file, quantize settings for any variable in the file
* may not be changed.
*
* Use of quantization is fully backwards compatible with existing
* versions and packages that can read compressed netCDF data. A
* variable which has been quantized is readable to older versions of
* the netCDF libraries, and to netCDF-Java.
*
* @param ncid File ID.
* @param varid Variable ID.
* @param quantize_mode Quantization mode.
* @param nsd Number of significant digits.
* @param quantize_mode Quantization mode. May be ::NC_NOQUANTIZE or
* ::NC_QUANTIZE_BITGROOM.
* @param nsd Number of significant digits. May be any integer from 1
* to ::NC_QUANTIZE_MAX_FLOAT_NSD (for floats) or
* ::NC_QUANTIZE_MAX_DOUBLE_NSD (for doubles).
*
* @returns ::NC_NOERR No error.
* @returns ::NC_EBADID Bad ncid.