Latest Contributions by MarcoBoeringa

Hi Guys, I have got an 18Gig .ecw file here at work, and a contractor has asked for a lower quality one that could be burned to DVD or put on thumb drive (i know we can get big thumb drive, but the DVD option is better for us) so im trying to work out how to convert the 18Gig to be a smaller 4gig file. I have done the obvious thing of opening it in Irfanview, clicking save as, then reducing quality to abot 3:1 as per the options, and this dramatically reduces the file size to about 10meg, while still being adequate for what contractor needs. But when i bring this new ECW into my MXD map it comes up with warning - see photo below. [ATTACH=CONFIG]19209[/ATTACH] So i open Catalog and import the same coord system as all my projects/files and try again, but the error still comes up, and the image doesnt project on my plan. Does anyone know why this is happening, and how i can resolve this? -Cheers Ben, There is no way an 18Gig ECW is compressable to just 10Mb without resampling / downsampling to a much, much more coarse resolution, e.g. create a 100x100m ECW of a high precision 0,2x0,2meter ECW file. You have to realize that ECW is already an extremely well compressed format (usually up to 20x and more), there is not much to gain by trying to recompress it, unless you are willing to sacrify a serious amount of the image quality by recompressing again at a target ratio of over 20:1, e.g. 50. The resulting image quality is likely so-so... In addition, you are miss-interpreting the Irfanview control. The compress ratio 3:1 is a target compression for the file size based largely on uncompressed raster size, meaning if you have a non-compressed file, a 3:1 ratio will reduce the file size to a third of the original. More normal values are, as visible in Irfanview, 20:1 or 10:1, meaning a 1Gb file will be reduced to 50 or 100Mb file size. In your case, if the 18 Gb image was an uncompressed TIFF, setting a 3:1 target compression would result in possibly a 6Gb ECW file at best. If I run a re-compress to ECW against an already well compressed small ECW of 11Mb with a target ratio of 3:1 in Irfanview, the file size actually INCREASES, to about 38Mb... This all means that in all likelyhood, the "Save As" in Irfanview simply failed. Are you able to view it back in Irfanview, and especially, zoom in to the same level of detail as you were in the original file? If not, this is again an indication the "Save As" failed as intended, and maybe Irfanview just compressed or wrote one of the higher level pyramids to a new file. By the way, Irfanview does offer a re-sampling option to save a new file to a coarser, and thus smaller file size, image. The option is available under File/Batch conversion and than under "Batch conversion settings" choose "Use advanced options/Resize". I usually find it the easiest to just choose "Set new size as percentage of original", and set for example  50% to reduce the number of image pixels to 1/4 of the original. Combine this with a moderate target compression of let's say 10:1, and you may have a decent smaller image with still good image pixel quality. ... View more

Sam, I can hardly read the screenshot you posted. Most forums, and this seems too, resize your screenshots to some predefined maximum allowable size. It is wise to stay below it, so as to prevent resizing, for example by selecting only the error window in an image editor (e.g. Windows Paint) and writing that to a file before attaching to a post. However, from what I see, it is clear that the Multiple Element Layout Manager (which I am not yet familiar with - is it some user submitted add-on for ArcGIS?), expects an extra field in your DDP index layer, if I read it right it must be named "pageNameTimID". You may be able to solve the issue by adding such a field, although it would be wise to consult the documentation, if any, to find out which fields, and their field types, are required for this application. Marco ... View more

You may also be able to solve this last issue by setting the "Resample during display using" option under the Layer properties "Display" TAB to bilinear interpolation or cubic convolution instead of the default nearest neighbour resampling. This will interpolate a value during display and zooming, giving smoother results. ... View more

Thanks for the feedback! That's good to know and I'll explore more into this. Jason Hi Jason, Although Eric is right that from a purely practical point of view "if the data meets the assumptions ... kriging should work", I would really like to emphasize the small caveat Eric placed in between these quotes and that I hereby rephrase: "Does it make sense to interpolate your particular dataset???" People all to easily grab to the first available tool that seems suited, while there may be better, and from a scientific point of view sounder, methods to accomplish what you want, e.g. create a map of potential customers. Interpolation always seems attractive when having a point dataset, as it is an "easy" way to get a surface, but is it sound from a logical and scientific point of view? I can't answer that question for you, but you might be... based on your knowledge and questions like the one below E.g.  do you find it likely that two people nearby have a higher likelihood to buy a certain product than two people further apart (spatial autocorrelation)? Does this almost always hold? (seems unlikely with market research data, two neighbours may have a completely different social background and status, but for good continuous environmental datasets it usually does) My gut feeling says that this type of "social" data is not the best suited for interpolation, and that you should be careful in your decision to use it and interpret results. I really shouldn't ignore general statistical analysis (multi-variate) like can be done with general statistics packages like NCSS and SPSS, and than use any found statistical relationships to classify other datasets with your market data to answer your question of "where potential customers may be". Yes, it is more laborious than the "one-stop point-to-surface option" that interpolation seems to offer, but it might be more sound from a scientific and statistical point of view. That is all not to say it can't be done, just that you should be careful in your decision and not ignore other options. And ESRI has of course "Business Analyst". Maybe time to look at that? Marco ... View more

Thanks Jeff, In my case, I finally decided to set the visibility of the layers on/off depending on data driven page index, as this did the job I wanted it to do for this particular case. It took some time to figure out how to implement this based on Python example scripts I found in the Help. I still think it would be nice if more of the DDP stuff was exposed through the ArcToolbox and thus directly usuable in ModelBuilder. Quite a lot of people are still unfamiliar with Python, and learning a new programming language can be a long story, especially for those without any previous programming experience or simply difficulties to adjust to programming type tasks. I am not one of them, but I have seen other people struggling with any kind of programming style "logic". Connecting things up in a graphic style designer like ModelBuilder, is just more accessible for some. Marco ... View more

From what I have seen up to now, if you want to stay within the realm of the DDP functionality and be able to use the standard tools and toolbar to accomplish what you want, there is no real other option than creating *multiple* parcels polygons for the same lot each having a single attribute of the type and content you want (parcel number, owner etc.). This is not an ideal situation, because it will mean having overlapping polygons, but you might automate the maintenance of the DDP polygon index layer by using ModelBuilder tools to stack polygons based on the same lot and add the attributes from whatever source you are using, and than schedule to update the layer each week or day or so... Problem is, it seems ESRI hasn't yet exposed much of the DDP functionality through python, except the most basic functions. Hence some stuff, like the "Page Definition" on a layer, isn't available programmetically. Seems we need to wait for ESRI to upgrade DDP functionality and expose more through programming interfaces like python. ... View more

Then when you do detrending, you're removing even more spatial autocorrelation, and there's nothing left to perform kriging on. Are you sure your data needed detrending? This is my interpretation too. Looks like the data doesn't need detrending. Try and read some of the documentation to understand what detrending is about and when there is, or isn't, a need to apply it. You shouldn't just use every tool or option available in Geostatistical Analyst just because it is there, you need to apply them based on knowledge of your dataset and statistics provided by Geostatistical Analyst. Simply viewing the dataset's values symbolized with an appropriate legend in ArcMap, should tell you a lot about a possible need to detrend the data. ... View more

I tried the simple kriging model as you suggested, but can I assume that the mean/trend is known and constant for my data? Thanks again! Kirsten This is something only you can answer with your expert and field knowledge of the terrain / research site. There are statistical tools in Geostatistical Analyst that will tell you whether some assumptions are more or less reasonable or appropriate based on statistics, but in the end it is you who needs to decide which models or assumptions are best for your data. ... View more

Are you using Background Processing? Processing in the background means sending the features you want to process over to another process and then getting a result back. Because its another process we have to persist them to disk for ArcMap to read them on the way back. Why o why didn't ESRI document this crucial factor in getting in_memory to work in the Help file??? I really can not find it in the main in_memory Help topic. This issue regarding background processing should be added under the "The following considerations must be made in deciding to write output to the in-memory workspace" text line. I have been struggling with this issue too. ... View more

You may also wish to have a look at this recent thread, as it discusses issues and solutions regarding 32-bit / 64 bit memory space and Python/ArcGIS too: Large Dictionary Compression? http://forums.arcgis.com/threads/58348-Large-Dictionary-Compression?highlight=32+bit+stream+network Marco ... View more

Some geoprocessing tools cannot take in_memory datasets as inputs/outputs. Yes, I was aware of that possibility. However, I still can not get the Con (conditional) tool of Spatial Analyst to accept the set extent on the "env" environment object, despite it being listed among the accepted "Environments" in the ArcGIS Desktop 10 Help. I clearly see it being set while debugging, as the correct extent with correct XMin, YMin, XMax, YMax is visible in PyScripter, but as soon as I use the Con tool in the script, the output is using the input raster extent instead of the set extent of the environment settings. The mask setting is properly used as long as the dataset is physically written to disk, as I wrote before. ... View more

I don't know if it has anything to do with it, but I now noticed that only when I specifically write the mask file to disk, it is properly used as a Mask environment setting. I had been using the "in_memory" option for storing the polygon representing the mask instead of physically writing it to disk. Maybe there is an undocumented limitation with using "in_memory" datasets as environment settings for analysis, and you can't use them for that directly...? Anyone else experience this issue? ... View more