Adding points to a map is a common task. We may wish to show the locations of stores, sampling equipment, fire hydrants or other items by marking their locations with points in a map. At times we will add points by importing geocoded tables. However, Manifold also makes it easy to interactively add points to a map. We can even add data at the same time we add a point to a map.
This example shows how to interactively add points to a map, using Windows classic style for the illustrations. We also use Instant Data mode and the Object Fields dialog to rapidly add a name for each point. We show how to move points by editing their coordinates in a table. Finally, we add labels.
Step 1: Prepare the map to be used.
In this example we will use the Bay Area map created in the My First Map example.
Open the Bay Area.map project file with File - Open. It appears as seen above when the map is opened.
Turn off the hydro layer by double clicking its layer tab and then turn off the roads layer by double clicking its layer tab. We don't need these layers for this example.
We do need an extra drawing layer in which we will add points.
To add a drawing layer, we right click on the roads layer and choose Add - New Drawing. A new drawing will be created in the project and will be added as a layer to the map just above the roads layer.
In the project pane we rename the new drawing to Stations and the drawing's table to Stations Table. We will pretend we are adding points that represent rapid response service stations for computer hardware repair.
Step 2: Add a field and prepare to add points
If we double click open the Stations Table we see it has no fields except the default ID field. We will add a text field called Name to the table. This will allow us to automatically add the name of each point as we enter it.
To add a field to the table we right click on a column head (like the ID column head shown above) and choose Add - Column.
In the Add Column dialog we specify "Name" for the name of the new field and choose its type to be ANSI text. Note that fields are created as integer numeric fields by default. Change the Type to ANSI text as seen above. Press OK and the field is created.
The table is still empty since there are no objects in the Stations drawing. Before adding points we will turn on Instant Data.
To do this, click on the map window so it has the focus with the Stations layer being active and choose Edit - Instant Data to turn on the check mark. When Instant Data is on, adding any objects to the drawing will pop open the Instant Data dialog that allows us to rapidly add a value to a field. Instant Data is extremely efficient when we need to add many objects with a note placed in a data field for each. See the Instant Data topic for details.
One last preparatory step: We click into the Format toolbar and choose bright green for the background color for points and 4 for their size. This will make the newly created points clearly visible.
Step 3: Add points using Instant Data
Click on the Insert Point tool to begin adding points.
Position the Insert Point cursor where the new point is to appear and click.
When we click to insert the point the Instant Data setting will cause the Object Fields dialog to automatically pop open. It will be pre-loaded with the Name field ready for editing since that is the only editable field in our table.
We can add the text value Marin and click OK (or simply press Enter).
A point appears in the Stations drawing in the map where we clicked.
If we look at the Stations Table we can see a record has been added for the point with the text value Marin in the Name field.
We can position the Insert Point cursor once more in the map and click.
When Instant Data is on, every time we insert a point the Object Fields dialog will launch to allow us to add a value. The dialog will launch with the last-edited field ready for editing with the last-used value already entered.
For this point we will use the text value San Francisco in the Name field and then press OK (or press Enter).
When we press OK another point appears in the Stations layer.
In the Stations Table another record appears for the new point with the text value San Francisco in the name field.
We can continue to click into the map in this fashion to add more points. With each point added we can specify the value for the Name field for that point in the Instant Data dialog. This is very fast.
For each point the Stations Table will be updated with the values we entered.
Step 4: Adjust positions using intrinsic fields
After adding a point to a drawing we may wish to adjust the latitude and longitude coordinates of the point to move it to a precise position. Suppose, for example, we've visited Intel in Santa Clara and have noted the exact coordinates of our service station location with a GPS. We would like to move the point we added for Intel to the exact latitude and longitude measured with the GPS.
We can accomplish this by showing intrinsic fields in the table and changing the values of those fields. Intrinsic columns are not shown by default in tables. We can use the View - Columns command to show intrinsic fields. See the Intrinsic Fields in Tables topic for details on intrinsic fields.
Turn on intrinsic fields by clicking open the Stations Table table and then choosing View - Columns. In the Columns dialog check the boxes next to the Longitude (I) and Latitude (I) intrinsic fields and press OK.
The intrinsic fields will appear in the table. To change the Longitude (I) position for Intel we simply double click into the cell, specify the value desired and press Enter.
To change the Latitude (I) value we likewise double click into the cell and edit the value as desired. The point will move to the new location specified by the intrinsic fields. [Depending on refresh settings, the points may not actually move in the drawing unless the drawing window is closed and then opened again.] Note: these values are made up values for the sake of this example. Intel is not located exactly at the position shown.
Step 5: Add labels to the map
If we like, we can use the Name field we've added to create labels for the new points. To do this, right click on the Stations drawing component in the project pane and choose Create - Labels in the context menu.
The Create Labels dialog will appear. The dialog knows we right clicked on the Stations drawing so it will highlight that drawing in the upper, Parent, pane assuming we want to create labels using the fields in that drawing.
We double click on the Name field in the Columns pane to add it as part of the label text in the lower pane. The other fields listed are intrinsic fields that we are not interested in using. Press OK to finish. See the Creating Labels from Fields topic for details on creating labels using this dialog.
The result is a new labels component called Labels that appears in the project pane underneath the Stations drawing. To show the labels in the map we drag and drop the Labels labels component from the project pane into the map window.
We can specify the alignment of the labels using the alignment controls in the format toolbar for labels. In the illustration above we've specified that the labels should appear below and to the left of their tie points. See the Aligning Labels topic for details.
Latitude and Longitude Notation in Editing
Manifold tables show latitude and longitude intrinsic fields using decimal degrees notation by default. When editing intrinsic fields, Manifold allows entry of values in either decimal or in degrees, minutes, seconds notation using almost any separator between the degrees, minutes and seconds values.
For example, if we want to enter a value of - 122.55125 degrees we can double click into the Longitude (I) box and enter any of the following:
-122.55125
-122d33m4.5s
-122 33 4.5
-122^33'4.5"
122.55125W
W122d33m4.5s
Manifold will interpret any non-numeric character in between the numbers other than a decimal point as a separator between degrees, minutes and seconds values. The letters W and S either before or after the other characters are commands to make the value a negative (west) longitude or negative (south) latitude.
Note that case is significant in NESW notation, so that 22d33m4.5s would be a North (positive) latitude and 22d33m4.5S or 22d33m4.5sS would both be South (negative) latitudes.
Whatever notation style is used to enter the new value, it will be displayed using the column format specified for that column.