VPROJ

Reproject shoreline


EnvironmentsPYTHON :: EASI :: MODELER
Quick linksDescription :: Parameters :: Parameter descriptions :: Return Value :: Details :: Example

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Description


Combines the vector output from TRANSEC and a text file to create a new predicted shoreline.
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Parameters


vproj(file, dbvs, tfile, fldnme, num1, dbsn, dbsd)

Name Type Caption Length Value range
FILE * str Input file name 1 -    
DBVS * List[int] Input vector segment 1 - 1  
TFILE * str Rates of erosion text file 1 -    
FLDNME * str Year of shoreline from which to project 1 - 64  
NUM1 * List[int] Number of years to predict 1 - 1  
DBSN str Output segment name 0 - 8  
DBSD str Output segment description 0 - 64  

* Required parameter
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Parameter descriptions

FILE

Specifies the name of the PCIDSK file to process. This file contains the vector segment generated by the TRANSEC function.

DBVS

Specifies the vector segment that contains the perpendicular transects generated by the TRANSEC function.

TFILE

Specifies the text file that contains the rates of erosion for each of the transects.

The format of the text file is:

 <ShapeId> <Erosion Rate meters/yearE (+ve or -ve)>
 ...
 ...

The first number is the ShapeId of the transect and the second number is the erosion rate in meters/year at that transect.

FLDNME

Specifies the field name of the year from which to project the new shoreline.

NUM1

Specifies the number of years by which to multiply the rate, to obtain the final shoreline.

DBSN

Optionally specifies a name (up to 8 characters) for the output segment.

DBSD

Optionally describes (in up to 64 characters) the contents or origins of the output data.

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Return Value

Returns: 

Type:  PCI_INT

Upon successful completion, this parameter holds the number of the output segment created.

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Details

This program projects shorelines with a greater degree of local control than the TRANSEC function. Given the vector transects produced by TRANSEC, VPROJ combines these transects with a text file.

The text file is a two-column file that contains the shapeid in the first column and the erosion rate in the second. The two numbers are separated by tabs or spaces. To skip a transect, simply omit the entry in the text file.

For each transect specified in the text file (TFILE), VPROJ multiplies the specified number of years to predict (NUM1) by the erosion rate and adds the calculated distance to the shoreline determined by the FLDNME (Shoreline Year) parameter.

For example, if NUM1 (Number of Years) is set to 10 and FLDNME (Shoreline Year) to "1950", the module will project 10 years from the 1950 shoreline.

The resulting shoreline is placed in its own vector segment.

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Example

This example demonstrates the use of VPROJ in generating a vector layer from TRANSEC and a text file to create a new predicted shoreline.

from pci.vproj import vproj

file	=	"maaexample.pix"	# input file
dbvs	=	[10]	# TRANSEC vector segment
tfile	=	"tableforvproj.txt"	# rates of erosion
fldnme	=	"1988"	# field name
num1	=	[10]	# number of years to project
dbsn	=	"VPROJ"	# output segment name
dbsd	=	""	# output segment description

vproj( file, dbvs, tfile, fldnme, num1, dbsn, dbsd )

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