CCAMLRGIS (version 3.0.7)

create_Lines: Create Lines

Description

Create Lines to display, for example, fishing line locations or tagging data.

Usage

create_Lines(
  Input,
  OutputFormat = "ROBJECT",
  OutputName = NULL,
  Buffer = 0,
  Densify = FALSE,
  Clip = FALSE,
  SeparateBuf = TRUE,
  NamesIn = NULL
)

Arguments

Input

the name of the Input data as a .csv file or an R dataframe. If a .csv file is used as input, this file must be in your working directory and its name given in quotes e.g. "DataFile.csv".

If NamesIn is not provided, the columns in the Input must be in the following order:

Line name, Latitude, Longitude.

If a given line is made of more than two points, the locations of points must be given in order, from one end of the line to the other.

OutputFormat

can be an R object or an ESRI Shapefile. if OutputFormat is specified as "ROBJECT" (the default), a spatial object is created in your R environment. if OutputFormat is specified as "SHAPEFILE", an ESRI Shapefile is exported in your working directory.

OutputName

if OutputFormat is specified as "SHAPEFILE", the name of the output shapefile in quotes (e.g. "MyLines") must be provided.

Buffer

Distance in nautical miles by which to expand the lines. Can be specified for each line (as a numeric vector).

Densify

If set to TRUE, additional points between points of equal latitude are added prior to projection (see examples).

Clip

if set to TRUE, polygon parts (from buffered lines) that fall on land are removed (see Clip2Coast).

SeparateBuf

If set to FALSE when adding a Buffer, all spatial objects are merged, resulting in a single spatial object.

NamesIn

character vector of length 3 specifying the column names of line identifier, Latitude and Longitude fields in the Input.

Names must be given in that order, e.g.:

NamesIn=c('Line ID','Line Latitudes','Line Longitudes').

Value

Spatial object in your environment or ESRI shapefile in your working directory. Data within the resulting spatial object contains the data provided in the Input plus additional "LengthKm" and "LengthNm" columns which corresponds to the lines lengths, in kilometers and nautical miles respectively.

To see the data contained in your spatial object, type: View(MyLines@data).

See Also

create_Points, create_Polys, create_PolyGrids, create_Stations, add_RefGrid.

Examples

# NOT RUN {

#If your data contains line end locations in separate columns, you may reformat it as follows:

#Example data:
MyData=data.frame(
  Line=c(1,2),
  Lat_Start=c(-60,-65),
  Lon_Start=c(-10,5),
  Lat_End=c(-61,-66),
  Lon_End=c(-2,2)
)

#Reformat to us as input as:
Input=data.frame(
  Line=c(MyData$Line,MyData$Line),
  Lat=c(MyData$Lat_Start,MyData$Lat_End),
  Lon=c(MyData$Lon_Start,MyData$Lon_End)
)

#Create lines and plot them
plot(create_Lines(Input=Input))


#Example 1: Simple and non-densified lines

MyLines=create_Lines(Input=LineData)
plot(MyLines,lwd=2,col=rainbow(length(MyLines)))

#Example 2: Simple and densified lines (note the curvature of the purple line)

MyLines=create_Lines(Input=LineData,Densify=TRUE)
plot(MyLines,lwd=2,col=rainbow(length(MyLines)))

#Example 3: Densified, buffered and clipped lines

MyLines=create_Lines(Input=LineData,Densify=TRUE,Buffer=c(10,40,50,80,100),Clip=TRUE)

plot(MyLines,lwd=2,col=rainbow(length(MyLines)))
plot(Coast[Coast$ID=='All',],col='grey',add=TRUE)

#Example 4: Buffered and grouped lines
MyLines=create_Lines(Input=LineData,Densify=TRUE,Buffer=30,SeparateBuf=FALSE)
plot(MyLines,lwd=2,border='blue')

# }
# NOT RUN {
# }