+
+ +
+

proj

+

Cartographic projection filter.

+
+

Synopsis

+
+

proj [-beEfiIlmorsStTvVwW] [args]] [+opt[=arg] …] file …

+

invproj [-beEfiIlmorsStTvVwW] [args]] [+opt[=arg] …] file …

+
+
+
+

Description

+

proj and invproj perform respective forward and inverse +conversion of cartographic data to or from cartesian data with a wide +range of selectable projection functions.

+

invproj may not be available on all platforms; in this case +use proj -I instead.

+

The following control parameters can appear in any order

+
+
+-b
+

Special option for binary coordinate data input and output through standard +input and standard output. Data is assumed to be in system type double +floating point words. This option is to be used when proj is a child process +and allows bypassing formatting operations.

+
+ +
+
+-d <n>
+
+ +
+

New in version 5.2.0: Specify the number of decimals in the output.

+
+
+
+-i
+

Selects binary input only (see -b).

+
+ +
+
+-I
+

Alternate method to specify inverse projection. Redundant when used with +invproj.

+
+ +
+
+-o
+

Selects binary output only (see -b).

+
+ +
+
+-t<a>
+

Where a specifies a character employed as the first character to denote a +control line to be passed through without processing. This option +applicable to ASCII input only. (# is the default value).

+
+ +
+
+-e <string>
+

Where string is an arbitrary string to be output if an error is detected during +data transformations. The default value is a three character string: *\t*. +Note that if the -b, -i or -o options are employed, an error +is returned as HUGE_VAL value for both return values.

+
+ +
+
+-E
+

Causes the input coordinates to be copied to the output line prior to +printing the converted values.

+
+ +
+
+-l<[=id]>
+

List projection identifiers that can be selected with +proj. proj -l=id +gives expanded description of projection id, e.g. proj -l=merc.

+
+ +
+
+-lp
+

List of all projection id that can be used with the +proj parameter. +Equivalent to proj -l.

+
+ +
+
+-lP
+

Expanded description of all projections that can be used with the +proj +parameter.

+
+ +
+
+-le
+

List of all ellipsoids that can be selected with the +ellps parameters.

+
+ +
+
+-lu
+

List of all distance units that can be selected with the +units parameter.

+
+ +
+
+-r
+

This options reverses the order of the expected input from +longitude-latitude or x-y to latitude-longitude or y-x.

+
+ +
+
+-s
+

This options reverses the order of the output from x-y or longitude-latitude +to y-x or latitude-longitude.

+
+ +
+
+-S
+

Causes estimation of meridional and parallel scale factors, area scale +factor and angular distortion, and maximum and minimum scale factors to be +listed between <> for each input point. For conformal projections meridional +and parallel scales factors will be equal and angular distortion zero. Equal +area projections will have an area factor of 1.

+
+ +
+
+-m <mult>
+

The cartesian data may be scaled by the mult parameter. When processing data +in a forward projection mode the cartesian output values are multiplied by +mult otherwise the input cartesian values are divided by mult before inverse +projection. If the first two characters of mult are 1/ or 1: then the +reciprocal value of mult is employed.

+
+ +
+
+-f <format>
+

Where format is a printf format string to control the form of the output values. +For inverse projections, the output will be in degrees when this option is +employed. The default format is "%.2f" for forward projection and DMS for +inverse.

+
+ +
+
+-w<n>
+

Where n is the number of significant fractional digits to employ for seconds +output (when the option is not specified, -w3 is assumed).

+
+ +
+
+-W<n>
+

Where n is the number of significant fractional digits to employ for seconds +output. When -W is employed the fields will be constant width +with leading zeroes.

+
+ +
+
+-v
+

Causes a listing of cartographic control parameters tested for and used by +the program to be printed prior to input data.

+
+ +
+
+-V
+

This option causes an expanded annotated listing of the characteristics of +the projected point. -v is implied with this option.

+
+ +

The +opt run-line arguments are associated with cartographic parameters. +Additional projection control parameters may be contained in two auxiliary +control files: the first is optionally referenced with the ++init=file:id and the second is always processed after the name of the +projection has been established from either the run-line or the contents of ++init file. The environment parameter PROJ_LIB establishes the +default directory for a file reference without an absolute path. This is +also used for supporting files like datum shift files.

+

Usage of +opt varies with projection and for a complete description +consult the projection pages.

+

One or more files (processed in left to right order) specify the source of +data to be converted. A - will specify the location of processing standard +input. If no files are specified, the input is assumed to be from stdin. +For ASCII input data the two data values must be in the first two white space +separated fields and when both input and output are ASCII all trailing +portions of the input line are appended to the output line.

+

Input geographic data (longitude and latitude) must be in DMS or decimal degrees format and input +cartesian data must be in units consistent with the ellipsoid major axis or +sphere radius units. Output geographic coordinates will be in DMS (if the +-w switch is not employed) and precise to 0.001” with trailing, zero-valued +minute-second fields deleted.

+
+
+

Example

+

The following script

+
proj +proj=utm +lon_0=112w +ellps=clrk66 -r <<EOF
+45d15'33.1" 111.5W
+45d15.551666667N -111d30
++45.25919444444 111d30'000w
+EOF
+
+
+

will perform UTM forward projection with a standard UTM central meridian +nearest longitude 112W. The geographic values of this example are equivalent +and meant as examples of various forms of DMS input. The x-y output +data will appear as three lines of:

+
460769.27     5011648.45
+
+
+
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+ + +
+