Express Yourself with the NEW Expression Builder

Those that upgrade to  MAP3D 2009 will now be able to use an expression in a friendlier environment thanks to the new expression builder.  Anyone that tried to create a complex label for a feature data set knows how hard it was to do in the 2007 or 2008 versions. You were limited to just a few options and you need to make sure the syntax was just right , even when the validate tool reported an error there may not of been an error.

First off depending on what the expression is for as to what the dialog will display.  You can use the create/modify expression not only to create a label but also to create a filter to query your data.

The expression dialog to create a label.

The expression dialog to filter your data.

Although the two dialogs look the same at first there are a few extra tools  in the filter dialog. The three “Getting Started with……”controls in both dialogs are useful for those that are just starting out creating expressions and will insert the correct code or syntax for those, for the advance users you can turn them off or just start entering your expression by clicking in the dialog box and typing away. So what options or tools are available now, lets take a look.  The screen shots below are from a SDF connection so the property menu will vary of you data.

So there you can see there’s a lot of tools to let you create an expression that you can now use, from converting a number value to a text to rounding the number and even doing a mathematical operation like add one value to another and drop the precision of the sum to 2 decimal places all in one expression.  The validate option will not only tell you if an error is present in the expression but also moves your cursor to the error in the expression allowing you to edit with out trying to figure out the error message.

Another nice feature it the ability to  save the expression to be used again.

The  save option creates a xml format file with the extension of fdg. The saved expression then can be loaded and used again with your data at another time.

So there you are a look at the new expression builder in AutoCAD MAP 3D 2009.  As time goes on I’ll post a few tips on how to use it.

Map 3D 2009 is on the Way.

So what’s new in AutoCAD Map 3D? I’m sure everyone has read or seen the blogs posting or news release on what’s new in AutoCAD 2009 but for the MAP 3D users what is new? Well there’s a couple new features that I think will make users happy. The first I’ll write about is the split and merge feature. For those that use the FDO, data connect, or what ever you want to call it these tools allow you to split a feature into two or more features and merge two or more features into one feature. An example would be a large parcel gets subdivided and you need to create th new parcels. The split feature can do it. Or say you have a group of small parcels that gets brought up by some bigger corporation and you need to merge all those small parcels into one big parcel, the merge feature can do it.

The commands are on the Modify menu in the Geospatial workspace by default, but you can also use the command line to call them up.

Here is a large parcel polygon that we need to split into two separate parcels. Select the feature to split then either use exiting lines or draw a new line to use as the cutting line.

 

The great thing about this tool is you can use the standard AutoCAD editing and creating tools to draw the dividing line with accuracy. No more guessing where the property line is at.

Once you create the dividing line the data table will add the new record(s) depending on the rules you set for the split.

The Merge features works similar, select the features and the data table deletes the old records and adds a new one based on the rules you set for the merge.

Here are some screen shots of the merge tool merging 3 parcels into one.

Notice the parcel address of 901, 933 and 991 and after the merge.

The rules I set for the merge allow me to use the attributes from the first parcel selected for the merged parcel.

So where and how do I set the rules for the split and merge features? One way is in the Options on the data table for the feature layer, select the Set Split and Merge Rules.

This opens up the palette to set all the rules you need for the schema that goes with that feature layer.

So what else is new? Well one change is the automatic check out of a feature. What this does is checks out a feature when you select it. There’s no need to select a feature and then right click to select “Check out feature”. This is enabled as default but you can turn it off from the Edit menu in the Geospatial workspace.

 

Another new feature is the “New” Expression editor. If you ever tried to create an expression in prior versions you will like this. I’ll post about that later, so stop back again in a few days.

Scale those AutoCAD Objects Based on Data Attached

Do you need to display some of your objects (blocks or points) based on the Object Data or database link values assigned to them? You know you can always do the attach the drawing and perform an alter-properties query on it method, but there is another way that may be shorter and easier if you do not like doing those queries.

By using the Display Manager, creating a new map, then set up a style using symbols, this method works with out using the FDO or data connect so you can use it on standard AutoCAD entities. Here is an example using simple a simple block called Existing_Hyd with OD attached.

Notice the OD field named PSI, that’s the field that we will use to scale the blocks. The values in my drawing for this field are 1000, 1500, 2000, & 2500. This is the water pressure at each of the hydrants in my map.

The first thing we do is create a new Map in the display manager (a map not a new dwg).

Click on the Data Icon and select New Map. Then change the name from New Map 1 to what ever you want. Next we add our drawing objects to this map.

Click the Data icon again and select “Add Drawing Data” then Drawing Layers. Select the layer the blocks or points are on.

It helps if the blocks or points you need to scale are on their own layer.

The blocks will now display in the map along with a map layer displayed in the display manager, but we need to set up a style. Right click on the new map layer and select “Add Style” “Symbol”

We now have a new element in the display manager named “Symbol style” and the blocks in the map took on a new look. This is normal and uses the default symbol of a square with an X in the middle of it as the symbol for the blocks.

To change this back to our block we right click on the “element” (Symbol Style) and go to the properties palette to make a few edits.

First rename the Style Name to reflect what the style is for, and then under the “Style Traits” select the block to use for the symbol. Note if you are using points and you want to use a block for the symbol the blocks must in defined in the current drawing.

The next item to edit is the “Scale” property for the symbol.

Use the Expression Chooser to select the Object Data field that you want to use to scale the blocks by.

Now the problem might be that the OD value is to way to large to use as a scale factor. Take my sample for instance. I want to use the PSI values to use, but those vales are up in the thousands, which makes the blocks WAY TOO BIG for my map. This is where the old legacy map shines verses the FDO ways and expression used there. With this method I can use a lisp expression to change the scale values right here in the property palette. The lisp expression I used is an arithmetic function that divides the OD value by 100 or by any number you desire.

There is a number of arithmetic functions listed in the help files under the expression evaluator that you can use if there you need to scale, rotate, or assign lineweight for the objects based on the data attached to objects just remember to include the opening and closing parentheses ( ) in the property value.