Performing a Mapcheck Analysis

2012-03-14

Product Documentation

Intermediate

Use the Mapcheck Analysis command to perform a mapcheck that is based on the precision of the annotation of the label object.

The Mapcheck Analysis command computes mapcheck calculations directly from the selected labels. To perform a mapcheck you must specify a point of beginning (POB) for each parcel. For each segment within the parcel, you select a label containing a direction, direction and distance, distance label, or curve label until the requirements to compute the next vertex of the current segment are met.

As you perform a mapcheck, temporary graphics are displayed in the drawing to indicate the sides that have been entered for each parcel. The current side is displayed in bold indicating origin and direction for that side. The temporary graphics also provide a visual confirmation of possible errors, or indicate that the direction of a line or curve needs to be flipped or reversed.

Note

The mapcheck report data is stored in the drawing database so you can continue a mapcheck from a previous AutoCAD Civil 3D session. The Mapcheck Analysis window must be open to enable the display of the temporary graphics.

From the POB, the annotation for each side in the parcel is used to calculate the coordinates of the endpoint of the side. As you enter data for each parcel, the Output View in the Mapcheck Analysis window updates to indicate error of closure and area based on the previously entered sides. Entering the information for the last side closes to the POB. The Mapcheck Analysis output view contains the following information:

POB coordinates
A sequential list of each course, direction and distance, or curve data, and end point coordinates
An error of closure summary: Error of closure: 1 part in <X parts>
Error of closure direction: <bearing or azimuth>
Error of closure distance: <distance>
Perimeter distance: <total distance around the parcel>
Area: <area units (acres/hectares, and square feet/meters>

For each parcel or survey figure, the area annotation is compared to the mapcheck area. If the error of closure is acceptable, for example a closure that exceeds one part in 10,000 parts and the area annotation matches, the annotations are considered to be mathematically correct.

You can copy the report content to the Windows Clipboard, or print it to a TAB delimited ASCII text file.

Tutorial Exercise: Performing a Map Check Analysis with Parcel Labels

To perform mapcheck analysis from AutoCAD Civil 3D label objects

Click Analyze tabGround Data panelSurvey drop-downMapcheck.At the Command prompt, enter Mapcheck.
In the Mapcheck Analysis window, click New Mapcheck Report.
Enter a name for the Mapcheck, for example LOT 1.
Click to Use Command Line Interface and follow the prompts at the command line.
Specify a Point of Beginning. The interactive graphics display the POB in the drawing.

Note
Colors displayed in the temporary graphics are controlled by the Mapcheck command settings. For more information, see Mapcheck Command Default Settings.

The following illustration shows the Point of Beginning:
At the command line you are prompted to select a label. After selecting a label, the interactive graphics display in the drawing. If you need to make a change, at the command line you have options to do the following:
- Clear: Clears the current side.
- New: Starts a new mapcheck report.
- Flip: Changes the direction of the curve to either clockwise or counter-clockwise.
- Reverse: Changes the direction of the line or curve.
Note
If the mapcheck requires more information to make the calculation, a red circle displays in the drawing and you are prompted at the command line.

The following illustration shows how the Reverse command can be used to change the direction of the mapcheck line:

The following illustration shows an example of using the Flip command:
Continue to follow the command line prompts by selecting labels until you return to the Point of Beginning.
The following illustration shows the continuation of the mapcheck towards the POB:
Click New Mapcheck to add a new mapcheck to the existing Mapcheck Report. Repeat steps 5 through 7.
Click Output View to review the mapcheck analysis report. Click to return to the input window.
Optionally, in either the Input View or the Output View, click Insert Mtext to insert either the current mapcheck or all mapchecks into the drawing. Specify an insertion point in the drawing and insert the Mapcheck Report.