ArcGIS Help 10.1 - LAS Dataset Statistics (Data Management)

Summary

Calculates or updates statistics for a LAS dataset and generates an optional statistics report.

Usage

Statistics calculate average point spacing for each LAS file by using a binning method that incrementally evaluates small areas of the file to determine an estimate.
Statistics enable filtering options for a LAS dataset layer to automatically display the available class codes and return values found in the referenced LAS files. The filtering options can be specified through the Layer Properties dialog box in ArcMap and ArcScene.
The following information about the LAS files will be stored in the LAS dataset and can be reviewed through the LAS Dataset Properties dialog box in ArcCatalog:
- Range of elevation and intensity values
- Number of data points per class code and return value
- Existence of RGB values
- LAS version and point format ID
- Project ID and file source ID
- Name of software used to generate the lidar file
The optional statistics report file provides an overview of LAS properties of all files in the LAS dataset or each individual LAS file in a text format that can be imported into any number of applications.

Syntax

LasDatasetStatistics_management (in_las_dataset, calculation_type, {out_file}, {summary_level}, {delimiter}, {decimal_separator})

Parameter	Explanation	Data Type
in_las_dataset	The input LAS dataset.	LAS Dataset Layer
calculation_type	Specifies whether statistics will be calculated for all lidar files or only for those that do not have statistics: SKIP_EXISTING_STATS —LAS files with up-to-date statistics will be skipped, and statistics will only be calculated for newly added LAS files or ones that were updated since the initial calculation. This is the default. OVERWRITE_EXISTING_STATS —Statistics will be calculated for all LAS files, including ones that have up-to-date statistics. This is useful if the LAS files were modified in an external application that went undetected by ArcGIS.	Boolean
out_file (Optional)	The output text file that will contain the summary of the LAS dataset statistics.	Text File
summary_level (Optional)	Specify the type of summary contained in the report. DATASET —The report will summarize statistics for the entire LAS dataset. This is the default. LAS_FILES —The report will summarize statistics for the LAS files referenced by the LAS dataset.	String
delimiter (Optional)	The field delimeter used in the text file. SPACE —A space will be used to delimit field values. This is the default. COMMA —A comma will be used to delimit field values. This option is not applicable if the decimal separator is also a comma.	String
decimal_separator (Optional)	The decimal character used in the text file to differentiate the integer of a number from its fractional part. DECIMAL_POINT —A point is used as the decimal character. This is the default. DECIMAL_COMMA —A comma is used as the decimal character.	String

Code Sample

LasDatasetStatistics example 1 (Python window)

The following sample demonstrates the use of this tool in the Python window:

import arcpy
from arcpy import env

env.workspace = "C:/data"
arcpy.LASDatasetStatistics_3d("test.lasd", "NO_FORCE", "LAS_FILE", 
                            "DECIMAL_POINT", "SPACE", "LAS_summary.txt")

LasDatasetStatistics example 2 (stand-alone script)

The following sample demonstrates the use of this tool in a stand-alone Python script:

'''*********************************************************************
Name: Modify Files in LAS Dataset& Calculate Stats for LASD
Description: Adds files & surface constraints to a LAS dataset, then 
             calculates statistics and generates report.
*********************************************************************'''
# Import system modules
import arcpy
from arcpy import env
import exceptions, sys, traceback

try:
    # Script variables
    env.workspace = 'C:/data'
    lasd = 'sample.lasd'
    oldLas = ['2006', '2007/file2.las']
    newLas = ['2007_updates_1', '2007_updates_2']
    oldSurfaceConstraints = ['boundary.shp', 'streams.shp']
    newSurfaceConstraints = [['sample.gdb/boundary', '<None>', 
                              'Soft_Clip']
                             ['sample.gdb/streams', 'Shape.Z', 
                              'Hard_Line']]
    arcpy.management.RemoveFilesFromLasDataset(lasd, oldLas, 
                                               oldSurfaceConstraints)
    arcpy.management.AddFilesToLasDataset(lasd, newLas, 'RECURSION', 
                                          newSurfaceConstraints)
    arcpy.management.LasDatasetStatistics(lasd, "UPDATED_FILES", 
                                          "lasd_stats.txt", 
                                          "LAS_FILE", "DECIMAL_POINT", 
                                          "SPACE", "LAS_summary.txt")
except arcpy.ExecuteError:
    print arcpy.GetMessages()
except:
    # Get the traceback object
    tb = sys.exc_info()[2]
    tbinfo = traceback.format_tb(tb)[0]
    # Concatenate error information into message string
    pymsg = "PYTHON ERRORS:\nTraceback info:\n{0}\nError Info:\n{1}"\
          .format(tbinfo, str(sys.exc_info()[1]))
    msgs = "ArcPy ERRORS:\n {0}\n".format(arcpy.GetMessages(2))
    # Return python error messages for script tool or Python Window
    arcpy.AddError(pymsg)
    arcpy.AddError(msgs)

Environments

Current Workspace, Scratch Workspace

Licensing Information

ArcGIS for Desktop Basic: Requires 3D Analyst or Spatial Analyst

ArcGIS for Desktop Standard: Yes

ArcGIS for Desktop Advanced: Yes

11/18/2013

LAS Dataset Statistics (Data Management)