ArcGIS Annoyance: Arc Map Crashes or Hangs when Plotting or Printing to PDF or a printer

ArcMAP will repeatedly crash when you try to print your map sometimes, usually when you are dealing with a large amount of on-screen data (in terms of both space it occupies on the hard drive as well as how complex the polygons are). If you are attempting to print or PDF a file that has, let's say a huge raster background and a very complex polygon layer draped over it, often ArcMAP will hang or crash. It may or may not give a memory message.

The reason for this is usually memory related. ArcMap manages memory poorly by comparison to some other software. Generally, as a rule of thumb, when you have a document open and it takes a long time to draw the layers when you pan, you might have this issue when you try to print your MXD.

The solution: Since it is usually memory related, there are a number of memory related fixes you can try to get ArcGIS to print or plot your document.

1) Try restarting your PC and immediately, once it has booted, go into the ArcMAP document and try to print/ export to PDF. This may work because on a fresh boot your RAM is clear, for the most part. Any actions you do after a fresh reboot slows your computer because the clean space in your RAM never fully recovers. More RAM will give the PC more space to create a PDF or make a file to be sent to the printer.

2) Reduce the output resolution DPI. Do this only if the quality level is acceptable, if you need the quality to be ultra high try one of the other solutions. Lower print qualities, especially for rasters, can really diminish the appearance of your mapping output.

3) Increase your pagefile size. If your document is failing to print for memory reasons, there may be no other solution than making your windows page file size larger so ArcMAP can handle the memory load. You can set page file size (maximum) in your control panel. This may fix this annoying ArcGIS 9.2/9.x issue.

AutoCAD Annoyance: Can't Select Some Text - SOLUTION!

AutoCAD 2008 (as well as 2007 to the best of my knowledge) features an annoying bug where you can select some of the Mtext on the page, but not others. There does not seem to be a rhyme or reason as to which text you can or can't select. It generally occurs in paper space, but I have had it happen in model space. You just can't select some of the words you have written. I have no solution to this issue, but I do have a work-around.

When you can't select some of the things you have written as mtext in autoCAD, simply type the command QSAVE (which is short for quick save). This saves you document and, inexplicably, enables you to select all text again. If this doesn't work for some reason, save your DWG document, close AutoCAD and re-open your DWG. This is a surefire way to 'fix' this bug.

Using Masks in AutoCAD to cover underlying features (hiding transparency)

In most programs, hiding underlying features is easy, but, in AutoCAD’s polygon/polyline based interface it is less easy. This article will outline three methods for whiteing out backgrounds in AutoCAD.

1) Text Masking: If you want text to have a black background (ie. White), enter the mtext properties, select “background mask” and click to select a mask that matches your background color (which may or may not be white). You can also use this command to select a colour of your choice to mask the text. Background masking can also work for other types of features and will be discussed at length in a future article.

2) The ‘wipeout’ command: this works well for an areal feature, like a polygon that surrounds text ie. Text in a box. Type the command wipeout, hit p for polyline, select the box surrounding your text in AutoCAD, then choose not to erase the box (obviously). What this will do is cover all of the features behind the feature you have selected. One draw back to this command, I find, is that when you re-open the document later, a bug often shifts the layer ordering, messing up what you have done. Silly AutoCAD!

3) Finally, when all else fails, a simple hatch can cure your AutoCAD woes. Select the polyline you wish to hide the interior of, type hatch (or h for short), choose solid color, then select the colour that matches your background by default.

Well, these three somewhat annoying to use commands are the only way, that I know of, to grey out background items in AutoCAD 2008. You should now be able to do away with transparencies in all of your CAD .dwg files. Hopefully.

AutoCAD Quirk: Escaping a Viewport in Paper Space

Normally you can just escape a viewport in paperspace by double clicking on the paperspace margin, but what if you were zoomed in too closely when you entered the simulated model space from paper space?

There is a button that exists just for such occasions and it is located with your snapping tools on the bottom toolbar. Unfortunately, a bug often prevents this button from appearing. So, in AutoCAD you need to click the tray settings dropdown in the bottom right hand corner and enable the "Model/Paper Space" button.

Arg, my paper space looks like model space!

Time Saving ArcGIS tip: Stopping Redrawing of large Rasters or Polygons

Doesn't it annoy you when you move the data pane slightly in ArcGIS and the whole image redraws?! I know it annoys me,

When you move the data pane and a large layer starts to redraw, simple punch ESC and the redraw will be cancelled. You may not be able to see the layer anymore, but rest assured, it's still there, it just hasnt been drawn on the screen.

Free Canadian GIS Data Sources - Complete List, will be Updated Periodically

The following list is a list I have compiled of Free Canadian GIS data. Before you rush out and buy expensive data, why not see if they have it here for free? The list has a lot of national data, but I apologize if it is a bit Ontario Centric. Since Ontario is where I do the majority of my work....

http://www.geobase.ca - Fairly updated, provides SPOT radarsat data for all of Canada. This is incomplete - should be completed by 2010. Also provides an up to date national road network, a hydro network for Canada. Landsat 7 10-30 m cell size satellite imagery for all of Canada.

http://www.geographynetwork.ca/ is a site published by ESRI Canada that provides free obm data for all of Ontario. You can find the free Ontario OBM data at : http://www.geographynetwork.ca/website/obm/viewer.htm specifically. All you need to do is sign up to get layers like forest, drainage, contours, roads and more. I should not that the data is often outdated and temporally sensitive features, like roads, may be quite out of date (circa 1998)

http://geogratis.cgdi.gc.ca/geogratis/en/index.html provides a whole gamut of Canadian geospatial data. There is simply too much to indicate here, you need to check it out for yourself. Some of the things I have used in the past are vegetation indices, population maps and more!

http://geodepot.statcan.ca/Diss2006/DataProducts/RNF2006_e.jsp - Statscan only provides road networks for free and I have yet to explore the data. However, I have heard they are fairly up-to-date and provide street names in the attributes. The data apparently is as recent as 2007, which beats the geographynetwork hands down

More is coming soon on this topic.

Matching Object Locations in AutoCAD

Moving and rotating features is easy in AutoCAD, if you do not need to be precise.... However, if you precisely need to match one feature to another spatially. eg. you have an updating drawing that needs to go in the exact same space that the old version does (and youve moved the old version). Or; you may need to line up two different objects. With this guide, it will be a snap (no pun intended)

You can do this with two relatively easy steps:

1) Use the Move commands and set osnap on endpoint. Choose an endpoint on the new object that corresponds exactly with an end point on the other object... If you just want to align the two features and not overlap them, skip this step.

2) Once you have moved one point of the new object to match the old object, you will likely need to rotate the new object to fit in the same constraints. This next portion will tell you what to do at each prompt.
>Use the ROTATE command.
Specify base point:>Select a base point on the object you are moving TOO rather than the object you are moving.
Specify rotation angle or [Reference]>Choose the Reference Sub command "type reference"
Specify the reference angle <0>Select the corresponding point on the new object that you wish to rotate by (eg. the same endpoint)
Specify second point:> Select a point that, when combined with the previous point, specifies the angle that you want the new feature to occupy
Specify the new angle: > Choose a final point that specifies the angle of rotation

I realize that these directions may seem confusing, but experiment if you don't get it right on the first try. This seems to be the only way to do this in AutoCAD. In GIS, this type of a proceedure might be called georeferencing (if we were dealing with rasters), in AutoCAD this sort of 'georeferencing' can be referred to as 'frustrating'.

Dealing with an AutoCAD file that has not been scaled: Improper Scale in a DWG!

Have you ever been handed a drawing done by someone else? Have you ever been handed a drawing done by someone else who doesn't seem to have the faintest clue about layouts, scales, or plotting? Where I work, we get handed DWG files from many different consultants. Each of them is inept or dinosaurish in some way. One difficult problem that I frequently encounter is CAD documents that are not properly scaled or dimensioned and won't print to a standard layout!

Assuming you don't know the size of the paper it was originally printed on,

One way to overcome this is to follow this proceedure:

1) find a feature on the document that has a known length and measure it using the distance tool (di is the short cut)
2) divide this length by the scale
3) this number is to be used when you plot
4) Select plot, plot window (drag a box over the entire drawing), choose a ratio for scale (eg. 1 mm = 10 mm), then
5) Hopefully plotting should work!

ArcGIS Tutorial: Giving Legend Elements the Same Transparency as the Polygons in the Data View

If you're like me and you often have to digitize landuse areas and have to overlay them on an orthoimage, then this guide might help you with a common issue in ArcGIS. When you edit a polygonal layer and manually digitize a land use (with heads up digitization), you usually want to make it transparent so you can see the airphoto/satellite image underneath it. The problem with ArcGIS 9.2 (and 9.0, 9.1) is when you generate a legend, the legend items do not show the same transparency.

So, for instance, if you use red to indicated a black parking lot in ArcGIS, then give the red shapefile 50% transparency. The actual, on screen, colour is kind of a very dark red. However, in the Legend you see bright red, as if there was no transparency.

To fix this, here is the solution:

1) Make sure you have the transparencies and colors as you want them, this ArcGIS procedure is semi-permanent (ie. time consuming and difficult to undo).
2) First, you make sure the eye dropper tool is enabled and on a toolbar (go to customize> commands > page layout to add it to a tool menu).
3) Use the eye dropper to select the color in the ArcMap viewport that you wish to change the legend item to. It will save it to your colour palette as a standard ArcGIS color (but only for the .mxd document you are working on). Do the same for all the layers you wish to correct the color for.
4) Now you have the colour information stored for each of the transparent layers you wish to update in the legend. Click on the legend, right click and select "Convert to Graphics". This will break the legend into individual editable units
5) Select the Box of color that you wish to correct to the transparent color.
6) Use the bucket fill tool - found in the drawing menu - to change the colour of each box to their respective corrected transparent colors.
7) At this point, each legend item should be corrected and we have succesfully worked around this annoying ArcGIS issue.

ArcGIS Tutorial: Manually Editing the Legend in ArcGIS/ArcMAP

The automatically generated legends in ArcGIS often get the job done, but when a level of customization is required, the default level of customization just isn't enough. This Post will attempt to give you some general insight into how to go about customizing ArcGIS legends.

1) First, you need to make the legend box into individual editable items. You do this by right clicking on the legend and selecting "Convert to Graphics". This breaks the ArcGIS legend format into its base parts.

2) You now need to select the legend as a whole and select ungroup (from the right click menu). You may also need to select each individual legend item and click ungroup again as they are often bound together

3) Now that your ArcMap legend is unbound, you can move each element around like as if they were drawn individually by you. ie. you can use the usual editing/drawing tools on them