A colleague conducted a field survey and recorded the start and end points of the transects with a GPS. These points have been imported to ArcMap 9.3 as 2 point layers. Both layers have a "transect number" field where each pair shares the same value, in order to match up start and end points.
I can manually "connect the dots," but there are about 1000 pairs of points, and I am hoping there's a quicker way.
Does anyone know of a simple script to run this procedure?
ET Geo Wizards has a function that will turn a set of points into lines. It produces a unique feature for each set of values based on a unique field value. Although it's not a free program, I believe this particular function is free to use without any limitations.
I saw this old avenue script. You could open it up, and apply the same logic in VBA. It will be fairly simple to automate, but cant find the equivalent 'ready to go' script in VBA.
Here's a python function that does something similar. link_value is the id that the points share. lat_fc is the output line featureclass.
def make_laterals( self ):
""" Uses 2 input FCs - SH and BH well locations - and creates a straight
as-the-crow-flies lateral line from the SH to the BH. """
from_sh_fc = args.surf_out_fc
to_bh_fc = args.bott_out_fc
lat_fc = args.laterals_output_dataset
skip_message = 'No corresponding point for link value %s - moving on...'
def add_print_message( msg, severity ):
""" Adds a message based on severity """
if severity == 0: self.gp.AddMessage(msg)
elif severity == 1: self.gp.AddWarning(msg)
elif severity == 2: self.gp.AddError(msg)
def create_point( x, y ):
""" Creates and returns point objects """
pnt = self.gp.CreateObject('Point')
pnt.x = x
pnt.y = y
return pnt
from_desc = self.gp.Describe(from_sh_fc)
to_desc = self.gp.Describe(to_bh_fc)
lb, rb = self.get_field_wrapper()
self.gp.CreateFeatureclass(os.path.split(lat_fc)[0], \
os.path.split(lat_fc)[1], 'POLYLINE', '', 'DISABLED', \
'DISABLED', self.spatial_ref)
out_desc = self.gp.Describe(lat_fc)
out_rows = self.gp.InsertCursor(lat_fc)
from_rows = self.gp.SearchCursor(from_sh_fc)
from_row = from_rows.Next()
point_array = self.gp.CreateObject('Array')
part_array = self.gp.CreateObject('Array')
while from_row:
from_feat = from_row.GetValue(from_desc.Shapefieldname)
from_x, from_y = map(lambda x: float(x), from_feat.centroid.split(' '))
from_point = create_point(from_x, from_y)
# Get value of LATID
link_value = from_row.GetValue(self.lat_id_field)
where_clause = '%s%s%s = %s' % (lb, self.lat_id_field, rb, link_value)
to_rows = self.gp.SearchCursor(to_bh_fc, where_clause)
to_row = to_rows.Next()
match_count = 0
while to_row:
to_feat = to_row.GetValue(to_desc.Shapefieldname)
to_x, to_y = map(lambda x: float(x), to_feat.centroid.split(' '))
to_point = create_point( to_x, to_y )
point_array.Add(from_point)
point_array.Add(to_point)
part_array.Add(point_array)
out_row = out_rows.NewRow()
out_row.SetValue(out_desc.shapefieldname, part_array)
out_rows.InsertRow(out_row)
point_array.RemoveAll()
part_array.RemoveAll()
to_row = to_rows.Next()
match_count+=1
#if match_count == 0:
#add_print_message( skip_message % link_value, 1 )
del to_row
del to_rows
from_row = from_rows.Next()
del out_row
del out_rows
del from_row
del from_rows
Here is a start. Script includes CreateLine procedure that takes in 4 parameters which are the line from and to point coordinates. For illustration purposes i added another procedure that lets you input the coordinates manually then calls the CreateLine procedure passing it the input coordinates. You must be 'editing' and the 'destination' line feature class has to be the 'target' layer.
You can modify the procedure for your purposes by adding in a loop that reads the input point features from your point features classes.
Public Sub CreateLine(From_X As Double, From_Y As Double, To_X As Double, To_Y As Double)
©Jakub Sisak, 2010
Dim pUID As New UID
Dim pEditor As IEditor
Dim pEditLayers As IEditLayers
Dim pActiveView As IActiveView
Dim pNewFeature As IFeature
Dim pPolyline As IPolyline5
Dim pFromPoint As IPoint
Dim pToPoint As IPoint
Dim TargetFeatureClass As IFeatureClass
pUID = "esriCore.Editor"
Set pEditor = Application.FindExtensionByCLSID(pUID)
Set pEditLayers = pEditor 'QI
Set pActiveView = pEditor.Map
If pEditor.EditState = esriStateNotEditing Then
MsgBox "You must be editing to use this feature!"
Exit Sub
End If
If Not pEditLayers.CurrentLayer.FeatureClass.ShapeType = esriGeometryPolyline Then
MsgBox "Target layer must be a polyline type!"
Exit Sub
Else
Set TargetFeatureClass = pEditLayers.CurrentLayer.FeatureClass
End If
pEditor.StartOperation
Set pFromPoint = New Point
Set pToPoint = New Point
Set pPolyline = New Polyline
pFromPoint.x = From_X
pFromPoint.y = From_Y
pPolyline.FromPoint = pFromPoint
pToPoint.x = To_X
pToPoint.y = To_Y
pPolyline.ToPoint = pToPoint
Set pNewFeature = pEditLayers.CurrentLayer.FeatureClass.CreateFeature
Set pNewFeature.Shape = pPolyline
pEditor.StopOperation "Create Polyline"
pActiveView.Refresh
End Sub
Public Sub PassLineParameters()
Dim From_X As Double, From_Y As Double, To_X As Double, To_Y As Double
'collect coordinates
From_X = InputBox("Enter From 'X' Coordinate:", "From X")
From_Y = InputBox("Enter From 'Y' Coordinate:", "From Y")
To_X = InputBox("Enter To 'X' Coordinate:", "To X")
To_Y = InputBox("Enter To 'Y' Coordinate:", "To Y")
CreateLine From_X, From_Y, To_X, To_Y 'call procedure to create line
End Sub
Simon's and Don's answers look like they will work, but I have also used this ArcScript in 9.2, Points2Lines.
If you don't mind taking alittle time to convert your data to where the begin and end of the transect are in two separate vectors (i.e.
ID BeginY BeginX EndY EndX
you can draw the lines using CrimeStat. It appears the Points2Lines script and the script the others having linked to will give you what you want as is.
