Automatic Turntable Calculation Tool

Melissa J Rura

CE 508 Dr. Shan10/29/2004

Introduction

What is turntable necessary for?Purpose of the projectHow to calculate turns? X,Y coordinates

Software Two datasets Simplified Actual

Methodology

Description of input data

Simplified dataset

Required output

Methodology

Calculate X,Y coordinates of the nodes

'========================='polyline_Get_X_FromPoint.cal'Author: Ianko Tchoukanski'http://www.ian-ko.com'=========================On Error Resume NextDim pMxDoc As IMxDocumentDim pMap As IMapDim pCurve As ICurveDim pFromPoint As IPointDim dXFrom As DoubleDim bSrefFromMap As Boolean'======================='Adjust the parameter below'bSrefFromMap = True ==> the coordinates will be calculated in the projection of the Map'bSrefFromMap = False ==> the coordinates will be calculated in the projection of the databSrefFromMap = True'=======================If (Not IsNull([Shape])) Then Set pCurve = [Shape] If (Not pCurve.IsEmpty) Then If (bSrefFromMap) Then Set pMxDoc = ThisDocument Set pMap = pMxDoc.FocusMap pCurve.Project pMap.SpatialReference End If Set pFromPoint = pCurve.FromPoint dXFrom = pFromPoint.X End IfEnd If__esri_field_calculator_splitter__dXFrom For the Y From point the line “dXFrom = pFromPoint.X” changes to “dYFrom = pFromPointY” For the X and Y To points the lines “ Set pFromPoint = pCurve.FromPoint dXFrom = pFromPoint.X” changes to : “Set pToPoint = pCurve.ToPointdXTo = pToPoint.X”and  “Set pToPoint = pCurve.ToPointdYTo = pToPoint.Y”respectively. This code can then be directly inputted in to the ArcGIS field calculator and the X and Y coordinates of any line segment can be calculated.

Import table into the tool – direct import or link tables through ODBCOpen the tool – Switchboard GUI

Step 1- intersections table1. First using the total_records_form the Tool counts the total

number of records, i.e. line segments in the attribute table 2. Begin a FOR loop from 1 to total number of records 3. In the table intersection create a new record for node j; where j

is the current node number4. Select all line segments where node j is the beginning node

(Fjunction) or ending node (Tjunction) of the line segment and record the number of line segments into the record for node j in the intersection table.

5. Retrieve and record X and Y coordinates for node j. 6. Repeat for each node then exit loop 7. Delete all nodes in the table intersections with less then 3 line

segments

Note the two attributesNote the two attributes

Intersections table contd.

This table can be exported using the export button under the Step 1 button and imported into ArcGIS as an XY Event point layer to visually check the accuracy of the intersections created

back

Step 2 – select_nodes formThe intersections table serves as the basis for the select_nodes form

Once all manual manipulations to the added attributes on the data are finished, clicking the Recalculate turntable button then generates the new turntable and its export variant This is done in a three-step process.

Output query

1)      Compute the interim turntable a.       Run a query to select the X and Y values for each node (F_Junction & T_Junction from the Almost table and the Intersection node from the Intersection table) in the possible route combination and the other modeling parameters from the Intersection table.b.      Write these values into the query Outputc.       Using the X,Y coordinates compute the angles for each combination and subtract them and assign the time

Final table

1)      Compute Final turntableRun a query to select the node

identifier, the F_Edge (beginning edge), the T_Edge (ending edge), and the assigned turn time as required by ArcView in order to declare a turntable

Conclusion and Future Work

generalizing the database to accept any street network attribute table and not to assume consecutive number beginning at 1 for the node identification modeling of a turn with only two segments intersecting should be addressed add other intersection attributes to the intersection table