The directives processed by the IDRISI writer are listed below. The suffixes shown are prefixed by the current <WriterKeyword> in a mapping file. By default, the <WriterKeyword> for the IDRISI writer is IDRISI.
DATASET
Required/Optional: Required
The value for this directive is the folder containing the IDRISI files to be written to. A typical mapping file fragment specifying an output IDRISI dataset looks like:
IDRISI_DATASET /usr/data/idrisi/output
IDEX_DATASET c:\idex\map.idx
Workbench Parameter: Destination IDRISI Vector Format Folder
DEF
Required/Optional: Required
Each IDRISI file must be defined before it can be written. The definition specifies the base name of the file, and the names and the types of all attributes. The syntax of a IDRISI DEF line is:
<WriterKeyword>_DEF <baseName> \
[<attrName> <attrType>]+
The attribute types supported are the same as those listed under the reader section.
The following table shows the DEF line directives that are supported by IDRISI. They are prefixed by the keyword “IDRISI_”.
|
Keyword Suffix |
Value |
Required/Optional |
|
TYPE |
The feature type of the file. In IDRISI, each file can contain only one feature type. The allowable types are idrisi_point, idrisi_line, idrisi_area and idrisi_text. |
Required |
|
FILE_TITLE |
Contains the descriptive name of the file. It is the name which is displayed at the top of the data file. If not specified, this defaults to “unknown”. |
Optional |
|
REF_SYSTEM |
The name of the geographic reference system used with the file. This may be Plane, or Lat/Long and so forth. If not specified, this defaults to “unknown”. |
Optional |
|
REF_UNITS |
The unit of measure used by the reference system. The recognized units are meters, feet, miles, kilometers, degrees and radians. This defaults to “meters” if not specified. |
Optional |
|
UNIT_DIST |
The scaling factor of the map in relation to the ground. This should be 1 in most cases and this defaults to 1 if not specified. |
Optional |
|
POSN_ERROR |
The degree of accuracy of the position of the feature in the vector file. If not specified, this defaults to “unknown”. |
Optional |
|
RESOLUTION |
The typical distance between points of a feature in the vector file. If not specified, this defaults to “unknown”. |
Optional |
|
VALUE_UNITS |
The unit of measure of the values used in the vector file. If not specified, this defaults to “unspecified”. |
Optional |
|
VALUE_ERROR |
The degree of error in the data values. For qualitative data, this is recorded as a proportional error value. For quantitative data, this should be recorded as a RMS error value. |
Optional |
|
FLAG_VALUE |
Any value in the vector file, which is not a data value, but has special meaning. This entry should remain blank if such value does not exist. |
Optional |
|
FLAG_DEF |
The definition of the above FLAG_VALUE. This field should remain blank if FLAG_VALUE does not exist. |
Optional |
|
LEGEND_CAT {<number>} |
The legend categories which shows up in the legend box when the vector file is displayed. The <number> can be any positive integer which is larger than 0. |
Optional |
|
COMMENT {<number>} |
Any additional information about the data. The <number> starts from 1 and increments by one for each additional comment line. |
Optional
|
|
LINEAGE {<number>} |
Any information regarding the history of how the data is recorded. The <number> starts from 1 and increments by one for each additional lineage line. |
Optional
|
|
completeness {<number>} |
The degree of how well the values describe the subject matter indicated. The <number> starts from 1 and increments by one for each additional lineage line. |
Optional
|
|
consistency {<number>} |
The logical consistency of the file. The <number> starts from 1 and increments by one for each additional consistency line. |
Optional
|
The following mapping file fragment defines two IDRISI files. Note that all but the IDRISI_TYPE are optional. There is no need to specify all of them.
The first file provides a simple example as to how some of the DEF lines are used. The second file gives an example which has two additional user defined attributes. Note that user-defined attributes are only allowed on Microsoft Windows platforms.
IDRISI_DEF landcover \
IDRISI_FILE_TITLE “ExampleFileTitle1” \
IDRISI_TYPE idrisi_area \
IDRISI_REF_SYSTEM “ExampleRefSystem” \
IDRISI_REF_UNITS kilometers \
IDRISI_LEGEND_CAT{-20} "ExampleLegendCat-20" \
IDRISI_LEGEND_CAT{1} "ExampleLegendCat1" \
IDRISI_LEGEND_CAT{-1} "ExampleLegendCat-1" \
IDRISI_COMMENT{1} "ExampleComment1" \
IDRISI_COMMENT{2} "ExampleComment2" \
IDRISI_COMMENT{3} "ExampleComment3"
IDRISI_DEF roads
IDRISI_FILE_TITLE “ExampleFileTitle2” \
IDRISI_TYPE idrisi_line \
IDRISI_REF_SYSTEM “ExampleRefSystem” \
IDRISI_REF_UNITS kilometers \
IDRISI_LEGEND_CAT{-20} "ExampleLegendCat-20" \
IDRISI_LEGEND_CAT{1} "ExampleLegendCat1" \
IDRISI_LEGEND_CAT{-1} "ExampleLegendCat-1" \
color char(20) \
style logical
COMPRESS_AT_END
Required/Optional: Optional
This statement instructs FME to compact the database after all writing has been done. This makes use of the existing MDB database option to compact. The compact operation compresses the output database to a small size on disk.
Example:
COMPRESS_AT_END Yes
Workbench Parameter: Compress Database When Done