BrainCrunch

ScalableMaps now come with help pages describing the features of our maps, useful tips and instructions on how to buy pre-made maps from our store and order custom maps.

cmd.bitmap_file = "output/walking_papers_{0}.png".format(page_id)

Southern Africa

More maps coming soon!

The site's list of maps is growing day by day and we are also doing custom-made maps when customers request them. There are also some free sample maps that you can try out. So go ahead and have a look!

Data hoarding for the sake of it?

Googling for "The requested name is valid, but no data of requested type was found" tells me it's some network-related issue. Maybe your ftp-upload command line is wrong - make sure the host parameter points to a valid IP or host name (without the port number).

 The [latest release](http://maperitive.net/download/Maperitive-latest.zip) comes with a new Python script called Alpenglow.py which renders a hillshading relief adding some yellowish tint to illuminated high slopes to enhance the 3D effect. It was inspired by the "[See the light: How to make illuminated shaded relief in Photoshop 6.0](http://www.shadedrelief.com/illumination/index.html)" article on the excellent [shadedrelief.com](http://www.shadedrelief.com/) site. You can run the script by executing run-python Samples/Python/Alpenglow.py The script generates the hillshading for a fixed map area in Switzerland, but you can change this quite easily in the script. You can also change other parameters, like shading (and alpenglow) colors, elevation ranges etc. The script also demonstrates the power of writing a **custom shader**. A shader transforms a small part of the digital elevation model (DEM) into a pixel color, based on the elevation, aspect and the slope of that part of the DEM. This way you can write your own hillshading effects function and then supply it to the generator. Here's how it's done for Alpenglow.py: # Execute the hillshading bitmap = ReliefUtils.generate_relief_bitmap(dem, relief_bbox, Srid.WebMercator, 1, alpenglow) The last parameter of the generate_relief_bitmap function is the shader function, in our case called alpenglow: # The actual shader function which is called for each pixel of the hillshading bitmap. # It receives the elevation, the aspect (orientation) of the slope and the steepnes (slope). def alpenglow(elevation, aspect, slope): sin_slope = math.sin (slope) nx = math.cos(aspect) * sin_slope ny = math.sin(aspect) * sin_slope nz = math.cos(slope) direction = dotproduct(nx, ny, nz, lx, ly, lz) direction = (direction - minDirection) / (1 - minDirection); if direction < 0: direction = 0 # This is how we can mix two colors together. shade_color = shade_base_color.mix (light_color, direction) if direction > 0.0 and elevation > min_alpenglow_elevation: elevation_factor = min((elevation - min_alpenglow_elevation) / delta_alpenglow_elevation, 1); alpenglow_factor = math.pow(direction, 4) return shade_color.mix (alpenglow_color, elevation_factor * alpenglow_factor).argb; return shade_color.argb;

UPDATE: my math was buggy, the eggs look a bit different after the correction. Note that the formula fails on very large distances (> 2000 km). A little Maperitive Python script I was playing with today, showing the line of distance of 3000 km (larger egg) and 2000 km (smaller egg) from my home town of Maribor, drawn on the standard Web Mercator projection map:  Here's the script: from maperipy import * import math location = Point(15.6530555556, 46.5575) distance = 3000000 layer = Map.add_custom_layer() symbol = PolygonSymbol("circle", Srid.Wgs84LonLat) symbol.style.pen_width = 8 symbol.style.pen_color = Color("blue") symbol.style.pen_opacity = 0.5 symbol.style.fill_opacity = 0 earth_circumference = 6371000 * math.pi * 2; points = [] arc = distance / earth_circumference * 360; for angle in range(0, 360): radians = math.radians(angle) y = location.y + math.sin(radians) * arc lat_factor = math.cos(math.radians(y)) x = location.x + math.cos(radians) * arc / lat_factor points.append(Point(x,y)) circle = Polygon(LinearRing(points)) symbol.add(circle) layer.add_symbol(symbol)

Learn how to find stuff on the internet.

The latest Maperitive 2.0 beta release comes with a new script which can generate a grid of bitmap exports similar to [walking papers](http://walking-papers.org/). The added value is that you can do walking papers for your own vector data and map styles, not just prerendered web tiles. ## How To Use A brief description of how to generate your own walking papers exports. ### 1. Define Map Area In Maperitive, place printing bounds on the map area you're interested in. The printing bounds do not have to match the dimensions of standard paper sizes. I choose the center of Ljubljana for this sample:  ### 2. Set Export Parameters There are a few settings in the **Samples/Python/WalkingPapers.py** script which you can use to control the exporting process (see the detailed instructions in the script itself): - **map scale**: this is the map scale for individual exported page. I choose 10,000, which in my case will result in a 2x3 pages grid. - **paper size and orientation**: you can leave the default A4 landscape, if you like. - **paper margins**: the default is 5 mm on each side of the page. - **page overlap**: this is a factor (from 0 to 0.25) which tells Maperitive how much adjacent pages should overlap. 0.25 means 1/4 of the page (on each side) will overlap. The default set in the script is 0.1 (10%). ### 3. Run The Script ... either by drag & dropping it into Maperitive or by executing run-python Samples/Python/WalkingPapers.py ## Sample Results Here's one of the exported pages:  ## Future Improvements You will be able to supply command-line parameters to these kinds of scripts in the future, so manual editing of the script before running it will no longer be necessary.

I've just received the "Oxford Bus & Cycle Map" from Richard Mann (thanks, Richard!). The interesting thing is that it was made from OpenStreetMap data using Maperitive. It's a stunning beauty, Richard has put a lot of effort into it. Online versions of the maps are here: http://www.transportparadise.co.uk/maps/   

Last week I posted a [quick survey for Maperitive](https://docs.google.com/spreadsheet/viewform?formkey=dHNoNFVmbGNLN0VZRFcyRG9sdERTMUE6MQ) users. The basic motivation was to see how many people are still using Windows XP SP2, so I can decide whether I can migrate Maperitive to .NET 4.0 (which is not available on SP2). But I added a few more questions in the mix, just for the fun of it. I got 138 reponses so far, which is much more than I expected, so thanks for everyone who participated. The results (I just copy&pasted charts from Google Docs, sorry for the labels cut-off): ### What operating system(s) are you using to run Maperitive?  Participants could choose multiple answers - in fact about 1/4 of participants were using Maperitive on multiple operating systems. About 4% of people marked they are using Windows XP SP2 - I am wondering what is the reason they haven't upgraded to SP3 (my guess is they are using Maperitive in corporate environments which tend to be slow on upgrades). Two things that I think are important from these results: 1. **I can start work on migrating to .NET 4.0**. For those unfortunate few who will be left out by this I can only say: **try to upgrade to Service Pack 3**. The official .NET 4.0 has been released two years ago (and first beta was released back in 2009) and it's increasingly hard to support development on older versions of .NET framework. 3rd party libraries Maperitive depends on have mostly migrated to .NET 4.0 and this means missing out on new features and bugfixes. 2. **A lot (50%) of people are using Maperitive on Linux and Mac**. This is much more than I expected and it means I will still have to keep Maperitive running on Mono. This is sometimes hard, since not everything is supported by Mono correctly. It also means a lot of people are willing to put up with an inferior user interface (due to Mono porting issues) for the sake of the functionality Maperitive offers. This is complimentary. ### What it is the main reason you're using Maperitive?  No surprises here, other than that at least 1/3 of users find Maperitive simple to use. This is a high number, given the fact that the documentation is not that good. There's one interesting (and a little bit surprising) answer: > _We can use OSM offline, without prerendering thousands of tiles. It is very helpful for emergency services, because you cannot rely on a mobile internet connection everywhere or in the case of a disaster._ ### What kind of a user do you consider yourself to be?  Looks like the main audience of Maperitive are users who like to hack. Only 18% of participants in the survey consider themselves to be non-technical. I guess that explains the large "simple to use" percentage in the previous question :) ### I use Maperitive mainly to...  Another question with multiple possible answers. I'm pleased that a lot of you are using Maperitive's "power tools" like tile generation and exporting. I'm also pleased that at least 37% of participants are using the SVG export functionality, which I worked hard to implement. ### I use Maperitive mainly for...  I guess I shouldn't be surprised that most of you are doing hobby mapping with Maperitive. As OpenStreetMap reaches more people (and companies), I think the percentage of non-profit and commercial usages will increase. ## Conclusion The survey is [still open](https://docs.google.com/spreadsheet/viewform?formkey=dHNoNFVmbGNLN0VZRFcyRG9sdERTMUE6MQ) (I think I will keep it open for some time), so you're welcome to have your say. There will be more surveys in the future - this one was done as an experiment, in just 5 minutes. Again, thanks for participating!

[The latest (2.0.28) Maperitive beta](http://maperitive.net/beta/) now comes with a sample Python script showing how you can override the default behavior of Maperitive tile generation process. The sample collects the generated tile files and then executes [OptiPNG](http://optipng.sourceforge.net/) on them to reduce the file size (OptiPNG is now included in Maperitive package) of PNGs. Some more info about this release: http://groups.google.com/group/maperitive/browse_thread/thread/492671b461f1e1da Here's the source for the sample, I think it's self explanatory: from maperipy import App from maperipy import Map from maperipy.webmaps import Tile from maperipy.tilegen import TileGenCommand def func1 (zoom, x, y, tiles_horizontal, tiles_vertical): # Demonstrates how to control which tiles get rendered # note that Maperitive generates tiles in batches # (defined by tiles_horizontal x tiles_vertical count). # So for example, 3x3 (=9) tiles are generated in a single bitmap # and then later they are split into individual tiles. # In this case we just print some info to Maperitive's command log window. print "Generating tile batch: {0}/{1}/{2} ({3}x{4} tiles)" \ .format(zoom, x, y, tiles_horizontal, tiles_vertical) # In this case we return True to signal that we want # these tiles to be rendered. return True def func2 (tile): # Demonstrates how to control the saving of a tile to disk. # At this point we could do some postprocessing of the tile bitmap # or store it somewhere else (and then return False to prevent # Maperitive from saving it to the default location). print "Saving tile: {0}/{1}/{2} (file: {3})" \ .format(tile.zoom, tile.tile_x, tile.tile_y, tile.file_name) # You could, for example, store tiles into a database instead # of writing them to disk. # In this case we return True to signal that we want # the tile to be saved to the default location. return True def optimize_tiles(): args = [] # Turn on backup files (just to compare sizes with optimized tiles). #args.append ("-backup") # Set the OptiPNG optimization rate (0 to 7), 7 being very slow. optimization_rate = 2 args.append ("-o{0}".format(optimization_rate)) # We don't want any OptiPNG output text to clutter Maperitive. args.append ("-quiet") args.extend(tiles_to_optimize) # This is one way to execute external programs. App.run_program("tools/OptiPNG/optipng.exe", 100, args) # Clear the list. del tiles_to_optimize[:] def collect_tiles (file_name): # Demonstrates how to collect the list of generated tiles. # You could, for example, use this function to upload # tiles to a Web server. # In this case we collect the file names to a list... tiles_to_optimize.append(file_name) # ... and then we call OptiPNG when the list gets full. if len(tiles_to_optimize) >= 10: optimize_tiles() tiles_to_optimize = [] # Generate tiles for the currently set geometry bounds and the current zoom level # (Map.position.zoom, Map.position.zoom) -> min.zoom, max.zoom cmd = TileGenCommand(Map.geo_bounds, Map.position.zoom, Map.position.zoom) # This is how we override TileGenCommand with custom functions. cmd.tile_generation_filter = func1 cmd.tile_save_filter = func2 cmd.after_tile_save = collect_tiles cmd.execute() # Run the optimization again for any left-over tiles. optimize_tiles()

Occasionally I make digital maps for customers based on OpenStreetMap data. Sometimes they request the maps in form of bitmaps, and sometimes they need a vector format like SVG or PDF in order to be able to edit the maps in Adobe Illustrator. Of course, the issue of license always pops up and often have to explain the stipulations of [CC BY-SA 2.0](http://creativecommons.org/licenses/by-sa/2.0/) to them. Soon OSM will switch to a new [ODbL license](http://opendatacommons.org/licenses/odbl/). I have to admit I mostly stayed away from the numerous legal talks that were going on various OSM channels, simply because I feel much more productive coding than participating in [endless strings of emails](http://article.gmane.org/gmane.comp.gis.openstreetmap.legal/6261). But now that the new license is here, I need to get acquainted with it from the perspective of someone trying to make (some) living out of OSM data. "_I'm not a lawyer_" is the usual phrase you can see in OSM legal discussions, but waiting for one to give you some solid information is like waiting for Godot, so I'll make judgements based on my own understanding and some common sense instead, and simplify things when I feel like it. If anyone objects, they can [twitter me](https://twitter.com/#!/breki74) with their objections and I'll try to correct things. So let's say a customer requests an SVG map of my home town and I decide to use OSM data for it. For the sake of simplicity the map will be based **purely** on OSM data, so no other sources. Let's first look at some of the important definitions in ODbL (emphases are mine): >> “**Database**” – A collection of material (the Contents) **arranged in a systematic or methodical way** and **individually accessible** by electronic or other means offered under the terms of this License. >> “**Derivative Database**” – Means a database based upon the Database, and **includes any translation, adaptation, arrangement, modification, or any other alteration** of the Database or of a **Substantial part** of the Contents. This includes, but is not limited to, Extracting or Re-utilising the whole or a Substantial part of the Contents in a new Database. >> “**Contents**” – The contents of this Database, which includes the information, independent works, or other material collected into the Database. For example, the contents of the Database could be factual data or works such as **images, audiovisual material, text**, or sounds. >> “**Produced Work**” – a work (such as an **image, audiovisual material, text**, or sounds) resulting from using the whole or a Substantial part of the Contents (via a search or other query) from this Database, a Derivative Database, or this Database as part of a Collective Database. >> “**Substantial**” – Means substantial in terms of **quantity or quality** or a combination of both. **The repeated and systematic Extraction or Re-utilisation of insubstantial parts of the Contents may amount to the Extraction or Re-utilisation of a Substantial part of the Contents.** So the first open question: **is an SVG map a Produced Work or a Derivative Database**? Or both? SVG map is an XML file that contains projected geographical data (together with visual styling attributes). OSM XML file can safely said to be a database. If you say SVG is not a database, where do you draw the line? What about KML or GML files? This question is important because of the next clause: >> Access to Derivative Databases. If You Publicly Use a Derivative Database or a Produced Work from a Derivative Database, You must also offer to recipients of the Derivative Database or Produced Work a copy in a **machine readable form** of: >>> a. **The entire Derivative Database**; or >>> b. A file containing all of the alterations made to the Database or the **method of making the alterations** to the Database (such as an **algorithm**), including **any additional Contents**, that make up all the differences between the Database and the Derivative Database. If the SVG map file is **not** considered a Derivative Database, then you have an option of supplying the original OSM data (OSM XML file, PBF file or even a database snapshot) together with the SVG file or providing a description of how you derived the Derivative Database. On the other hand, I can argue that SVG **is** a Derivative Database because it is "_arranged in a systematic or methodical way and individually accessible_" and "_includes any translation, adaptation, arrangement, modification, or any other alteration_" of the original OSM data. So in that case simply publishing the SVG file (and only that file) would cover the license requirements. I should note that the SVG map has to be released under the ODbL or a compatible license. Now let's go one step further. Let's assume (as I do) SVG **is** a Derivative Database. What if I then generate a PNG bitmap (or a Web map, for that matter) from the SVG file using Adobe Illustrator and want to publish that, too? One could argue that a bitmap is a Produced Work and since we already published the Derivative Database that produced this Work, we are covered. But what if I didn't generate the Web map from the SVG, but used a tool like Mapnik or Maperitive and generated it **directly from an OSM extract instead**? Let's say that for practical purposes I don't want to publish 1 GB of OSM data and I choose to go down the path of describing the "_method of making the alterations_" I did to generate the bitmap. What are the options here? 1. I could write a detailed description of steps I performed to generate the Web map. Osmosis, Mapnik with all the batch scripts etc. I could even post the source code of the program(s) I used. 1. On the other hand, I could just describe the process in a sentence or two. I could also say I used a special filter in Photoshop. I can partly understand the spirit of the "method" clause - to enable access to the interesting derivations of the original data. But I see several holes in the "method" definition: 1. What if I produced the map by **arranging a lot of the map elements manually, by hand**? This is quite a common case when you have to place map labels in order to avoid label conflicts. How would I describe the "method" other than saying that I did it by hand? How would that help anyone? 1. What if I used an **expensive proprietary software** (like Illustrator or Photoshop)? Or even a piece of code that I haven't released to anyone else? In that case nobody else would be able to reproduce the method. **Does the "Contents" cover source code as well**? It doesn't mention the source code explicitly. If it does, then that implies **you can only use open source software with OSM data**, which would be silly. 1. What about complex algorithms? How detailed the description would have to be for someone to be able to reproduce the algorithm? I've tried reproducing various algorithms from long scientific articles and I can tell you it's not an easy task even if you have a detailed description. Frankly, I don't see how the "method" clause could be enforced in practice. (**UPDATE**: now that I thought about it once more, the clause only talks about describing the method of arriving to the Derivative Database and not to the Produced Work itself. So I could just say "I downloaded the OSM extract from Geofabrik" and that would be it.) One final question: **does extracting OSM data for a city amount to a "substantial part" of the original OSM database?**

‘Software bloat’ is widely agreed to be a negative attribute. However, the decision to add multiple alternative options to a system may be seen as a positive good rather than an invidious compromise. We speculate that freedom of choice may be considered a desirable attribute (even a design aesthetic) by many OSS developers. The end result is an application that has many configuration options, allowing very sophisticated tailoring by expert users, but which can be bewildering to a novice (Nielsen, 1993, p. 12). The provision of five different desktop clocks in GNOME (Smith et al., 2001) is one manifestation of this tendency; another is the growth of preferences interfaces in many OSS programs (Thomas, 2002). Thus there is a tendency for OSS applications to grow in complexity, reducing their usability for novices, but with that tendency to remain invisible to the developers who are not novices and relish the power of sophisticated applications. Expert developers will also rarely encounter the default settings of a multiplicity of options and so are unlikely to give much attention to their careful selection, whereas novices will often live with those defaults.

And of course, ask your users.