R: Variable length records tools

header_add_extrabytes {rlas} | R Documentation

## Variable length records tools

### Description

Functions that update a header to describe variable length records according to the LAS specifications

### Usage

    header_add_extrabytes(header, data, name, desc)

    header_add_extrabytes_manual(header, name, desc, type, offset = NULL,
      scale = NULL, max = NULL, min = NULL, NA_value = NULL)

### Arguments

`header` | list
`data` | vector. Data that must be added in the extrabytes attributes.
`name` | character. The name of the extrabytes attributes to add in the file.
`desc` | character. The description of the extrabytes attributes to add in the file.
`type` | integer. The data type of the extrabytes attributes (page 25 of the spec).
`scale, offset` | numeric. The scale and offset of the data. NULL if not relevant.
`min, max` | numeric or integer. The minimum and maximum value of the data. NULL if not relevant.
`NA_value` | numeric or integer. NA is not a valid value. At writing time it will be replaced by this value that will be considered as NA. NULL if not relevant.

### Examples

    data = data.frame(X = c(339002.889, 339002.983, 339002.918),
                      Y = c(5248000.515, 5248000.478, 5248000.318),
                      Z = c(975.589, 974.778, 974.471),
                      gpstime = c(269347.281418006, 269347.281428006, 269347.281438006),
                      Intensity = c(82L, 54L, 27L),
                      ReturnNumber = c(1L, 1L, 2L),
                      NumberOfReturns = c(1L, 1L, 2L),
                      ScanDirectionFlag = c(1L, 1L, 1L),
                      EdgeOfFlightline = c(1L, 0L, 0L),
                      Classification = c(1L, 1L, 1L),
                      ScanAngle = c(-21L, -21L, -21L),
                      UserData = c(32L, 32L, 32L),
                      PointSourceID = c(17L, 17L, 17L),
                      treeID = c(1L, 1L, 1L))

    lasheader = header_create(data)
    lasheader[["Variable Length Records"]]

    lasheader = header_add_extrabytes(lasheader, data$treeID, "treeID", "An id for each tree")
    lasheader[["Variable Length Records"]]

[Package rlas version 1.2.4 Index]