ShapeLib Tools - User Guide
ShapeLib is maintained by Frank Warmerdam
This guide was created by Eduardo Patto Kanegae < eduardo~at~consultoria~dot~eti~dot~br >
Purpose: creates a new and empty .dbf file.
Usage: dbfcreate xbase_file [[-s field_name width],[-n field_name width decimals]]...
- xbase_file: the name of xBase file to be created. Doesn't need the extension.
- -s field_name width: creates a string field with name field_name and size width.
- -n field_name width decimals: creates a numeric field with name field_name, width of width and with decimals places sized by decimals.
Example
$ dbfcreate testbase -s NAME 20, -n AREA 9 3, -n VALUE 9 2
# this will create a file named testbase.dbf with 3 fields: NAME ( string (20)),
AREA ( float (9,3)) and VALUE ( float (9,2))
Purpose: adds a record into an existing .dbf file.
Usage: dbfadd xbase_file field_values
- xbase_file: the name of an existing xBase file.
- field_values: list of values to be inserted into the xBase file.
You must specify a number of values equal to the number of fields the xBase file has.
The order of values must also reflect the order of fields inside xBase file.
Example
$ dbfadd testbase.dbf REGION1 25.656 150.22
# assuming that testbase.dbf has 3 fields( NAME, AREA and VALUE), this command line
will insert a new record into testbase.dbf with the value "REGION1" for NAME,
'25.656' for AREA and '150.22' for VALUE field.
Purpose: dumps the content of a xBase file to the terminal.
Usage: dbfdump [-h] [-r] [-m] xbase_file
- -h: output header info( field descriptions).
- -r: output raw field info, numeric values not reformatted.
- -m: output one line per field.
- xbase_file: the name of an existing xBase file.
Example
$ dbfdump -h testbase.dbf
# assuming that testbase.dbf has 1 record( inserted by previous example using 'dbfadd'),
this command line will produce the following output:
Field 0: Type=String, Title=`NAME', Width=20, Decimals=0
Field 1: Type=Double, Title=`AREA', Width=9, Decimals=3
Field 2: Type=Double, Title=`VALUE', Width=9, Decimals=2
NAME AREA VALUE
REGION1 25.656 150.22
Purpose: creates a new and empty shapefile.
Usage: shpcreate shp_file [point|arc|polygon|multipoint]
- shp_file: the name of shapefile to be created. Doesn't need the extension.
- point/arc/polygon/multipoint: the type of shapefile that you wish to create. You must specify a valid option.
Example
$ shpcreate testpolygon polygon
# this will create a point shapefile named testpolygon( in fact testpolygon.shp and testpolygon.shx will be created).
Purpose: adds a shape into an existing shapefile.
Usage: shpadd shp_file [[x y] [+]]*
- shp_file: the name of an existing shapefile.
- x1 y1 x2 y2 ... xn yn: the set of x,y coordinates that describes the shape that you wish to add. Note that you must specify the correct number of parameters for a given type of shapefile. e.g.: for point shapefiles you have to pass 1 pair of XY coordinates and for a polygon shapefile you should pass at least 4 pairs of XY coordinates( where the first and the last point must have the same coordinates).
Example
$ shpadd testpolygon 100000 7000000 250000 6500000 200000 6000000 100000 7000000
# assuming that testpolygon is a polygon shapefile, this command line will insert a new shape( a triangle) into testpolygon with the following XY coordinates:
vertice 0: 100000 7000000 ( this will also be the vertice where the shape starts and ends)
vertice 1: 250000 6500000
vertice 2: 200000 6000000
vertice 3: 100000 7000000
Purpose: dumps content of shapefile showing information like shape type, file extents, total of objects and vertices coordinates.
Usage: shpdump [-validate] shp_file
- -validate: count the number of objects that has invalid ring orderings.
- shp_file: the name of an existing shapefile.
Example
$ shpdump testpolygon
# assuming that testpolygon is an existing shapefile previously created, this command line will output the following result:
Shapefile Type: Polygon # of Shapes: 1
File Bounds: ( 100000.000, 6000000.000,0,0)
to ( 250000.000, 7000000.000,0,0)
Shape:0 (Polygon) nVertices=4, nParts=1
Bounds:( 100000.000, 6000000.000, 0, 0)
to ( 250000.000, 7000000.000, 0, 0)
( 100000.000, 7000000.000, 0, 0) Ring
( 250000.000, 6500000.000, 0, 0)
( 200000.000, 6000000.000, 0, 0)
( 100000.000, 7000000.000, 0, 0)
Purpose: validates and resets the winding order of rings in polygon geometries to match the ordering required by shapefile specification. This is useful for shapefiles having troubles when checked with a 'shpdump -validate'.
Usage: shprewind in_shp_file out_shp_file
- in_shp_file: the name of an existing shapefile.
- out_shp_file: the name of the new fixed shapefile that will be created.
Example
$ shprewind badshapefile newshapefile
Purpose: displays basic information for a given xBase file, like number of columns, number of records and type of each column.
Usage: dbfinfo xbase_file
- xbase_file: the name of an existing xBase file.
Example
$ dbfinfo testbase
Info for testbase.dbf
3 Columns, 1 Records in file
NAME string (20,0)
AREA float (9,3)
VALUE float (9,2)
Purpose: appends the records of a source xBase file into a destiny xBase file. Both files must have the same number of fields.
Usage: dbfcat [-v] [-f] from_DBFfile to_DBFfile
- -v: verbose mode.
- -f: forces data conversion if data field types is not the same at both files or if is there any null value into from_DBFfile.
- from_DBFfile: source xBase file.
- to_DBFfile: destiny xBase file.
Example
$ dbfcat -v testbase1 testbase2
Purpose: displays basic information for a given shapefile, like shapefile type, number of objects and its extents.
Usage: shpinfo shp_file
- shp_file: the name of an existing shapefile.
Example
$ shpinfo testpolygon
Info for testpolygon
Polygon(5), 1 Records in file
File Bounds: ( 100000, 6000000)
( 250000, 7000000)
Purpose: appends the content of a source shapefile into a destiny shapefile. Both files must be the same shapefile type.
Usage: shpcat from_shpfile to_shpfile
- from_shpfile: source shapefile
- to_shpfile: destiny shapefile
Example
$ shpcat shapefile1 shapefile2
Purpose: computes XY centroid for polygon shapefiles.
Usage: shpcentrd shp_file new_shp_file
- shp_file: the name of an existing polygon shapefile.
- new_shp_file: the name of the point shapefile that will created.
Example
$ shpcentrd apolygonfile pointcentrd
Purpose: creates a DXF file from an existing shapefile.
Usage: shpdxf shapefile {idfield}
- shapefile: the name of an existing shapefile.
- idfield: explain
Example
$ shpdxf testshapefile IDFIELD
# explain the command
Purpose: Utility program to fix nulls and inconsistencies in Shapefiles
as happens from time to time.
Usage: shpfix shpfile new_file <Record# to Blank>
- shpfile: input file
- new_file: output file
Example
$ shpfix broken fixed
Purpose: Reproject Shapefiles using PROJ.4
Usage: shpproj shp_file new_shp ( -i=in_proj_file | -i="in_params" | -i=geographic ) ( -o=out_info_file | -o="out_params" | -o=geographic )
- param1: explain
- param2: explain
INPUT
Input can come from one of three sources. A projection parameter file,
directly through parameters or geographic. If the shapefile has an associated
prj file, name the same as the shapefile but ending in ".prj" it will be used
by default ignoring all other parameters. If input is omitted it defaults to
geographic, unless the default prj file exists.
OUTPUT
Output can come from one of three sources. A projection parameter file,
directly through parameters or geographic. If output is omitted it defaults
to geographic.
PROJECTION PARAMETER FILE
This file MUST end with the extension ".prj". It has the form of one
projection parameter per line. Parameters can be in any order. The
projection parameters are those used to define a PROJ.4 projection.
PROJECTION PARAMETERS
Are the same as used by proj and invproj.
use proj -lP to see available projections
proj -lu to see available units
proj -le to see available ellipsoid
Or visit the PROJ.4 web page at http://www.remotesensing.org/proj for more details.
Example
the following example projects file rowtest to row3, moving data from Stateplane NAD83 zone 1002 to utm zone 16 in meters
shpproj rowtest row -i="init=nad83:1002 units=us-ft" -o="proj=utm zone=16 units=m"
shpproj rowtest row3 -o="proj=utm zone=18 units=m" -i="zone=16 proj=utm units=us-ft"
shpproj rowtest row3 -o="proj=utm zone=18 units=m"
shpproj rowtest row3 -i=myfile.prj -o=geographic
shpproj rowtest row3 -is=myfile.prj