Why don't certain countries appear on the world map?
Tonga
Cook Islands
Somoa
Tahiti
Is there a way to modify the world map so that these countries do display?
Because they are too small to be properly represented on the world map. Take a look at this demo.
Related
Is there a way to plot data cubes with any kind of program? In order to plot this (1) image, I had to use TinkerCard, that by the way doesn't allow to put names along the data cube dimensions. Is there any kind of tool that allows do do something similar to (2) or (3)? Thanks in advance
I think this is a not possible.
The cubes which I play with all have atleast 10 dimensions.
The problem is that the short name, olap cube, suggests that some sort of pictorial representation is possible.
I think it is maybe better to remeber them using the fuller name multi-dimensional cubes.
Once past 3 dimensions I don't understand how it will be possible to draw a representative picture.
Saying all the above I have a book co-authored by Mosha Pasumadsky which contains some simple cube pictures similar to your picture. Also I attended a course run by Chris Webb and he used pictures of cubes to help our understanding. The pictures they have used are all very simplified, and of only small spaces within a full cube.
I've asked similar questions before and I'm still struggling.
I want to create geo based info graphics at the level of a city.
I need to be able to take some latitude/longitude values and project them such that they are centered and appropriately zoomed.
It would help me a great deal to see an example that plots a small number of points.
37.781040, -122.497681
37.720504, -122.495622
37.723220, -122.395028
This is roughly an L shape and all three points should be in San Francisco.
It could be as simple as 3 black dots on a white background. I hope to learn:
which projection?
how do you adjust the projection so that an area the size of San Francisco is on the canvas?
how do you translate those coordinates and position them on that canvas?
Could someone create such an example?
Thanks.
-Kelly
I created a simple example that works.
https://gist.github.com/kellyfelkins/9741723
I think I was making multiple mistakes that made it really difficult to correct.
In case others have troubles too, here are some things to watch out for:
The projection method expects an array. For a while I was passing it 2 arguments, but it needs a single argument that is an array.
The projection expects the values in longitude, latitude order.
-Kelly
I have been looking all over and seen lot of questions of this nature.
My problem is much simpler than generating a 3D world with heights and such.
I'd like to generate a 2D map in a limited space (15x15, 20x20 ...) based on a tileset.
Here is a random example what a simple result could look like:
Is anyone aware of an algorithm which is capable of executing such a task?
First, you should create a spritesheet that will have all the tiles you need.
Then you should create a class 'Tile', that will be able to render yourself (tile will be of fixed size, so it will not be hard)
Then, you should create a level. I mean, you should create a description of your level. You can do it in text format, xml or you can generate it randomly. For example, your level:
GGGGGGGG
GGGGGGGG
GGGBBGGG
GGGGGGGG
Where one letter means one tile (G is for grass, B is for bridge).
Then, when you've done it, you should iterate through your level descritpion and render it.
UPD. Sorry for misunderstanding your question. I use an excellent piece of software: "Tiled". It's open source and great! You cat create levels by drag and drop. And when completed you can export your level to xml, txt, json and other formats.
Is it possible to make a 3D representation of an object by capturing many different angles using a webcam? If it is, how is it possible and how is the image-processing done?
My plan is to make a 3D representation of a person using a webcam, then from the 3D representation, i will be able to tell the person's vital statistics.
As Bart said (but did not post as an actual answer) this is entirely possible.
The research topic you are interested in is often called multi view stereo or something similar.
The basic idea resolves around using point correspondences between two (or more) images and then try to find the best matching camera positions. When the positions are found you can use stereo algorithms to back project the image points into a 3D coordinate system and form a point cloud.
From that point cloud you can then further process it to get the measurements you are looking for.
If you are completely new to the subject you have some fascinating reading to look forward to!
Bart proposed Multiple view geometry by Hartley and Zisserman, which is a very nice book indeed.
As Bart and Kigurai pointed out, this process has been studied under the title of "stereo" or "multi-view stereo" techniques. To be able to get a 3D model from a set of pictures, you need to do the following:
a) You need to know the "internal" parameters of a camera. This includes the focal length of the camera, the principal point of the image and account for radial distortion in the image.
b) You also need to know the position and orientation of each camera with respect to each other or a "world" co-ordinate system. This is called the "pose" of the camera.
There are algorithms to perform (a) and (b) which are described in Hartley and Zisserman's "Multiple View Geometry" book. Alternatively, you can use Noah Snavely's "Bundler" http://phototour.cs.washington.edu/bundler/ software to also do the same thing in a very robust manner.
Once you have the camera parameters, you essentially know how a 3D point (X,Y,Z) in the world maps to an image co-ordinate (u,v) on the photo. You also know how to map an image co-ordinate to the world. You can create a dense point cloud by searching for a match for each pixel on one photo in a photo taken from a different view-point. This requires a two-dimensional search. You can simplify this procedure by making the search 1-dimensional. This is called "rectification". You essentially take two photos and transform then so that their rows correspond to the same line in the world (simplified statement). Now you only have to search along image rows.
An algorithm for this can be also found in Hartley and Zisserman.
Finally, you need to do the matching based on some measure. There is a lot of literature out there on "stereo matching". Another word used is "disparity estimation". This is basically searching for the match of pixel (u,v) on one photo to its match (u, v') on the other photo. Once you have the match, the difference between them can be used to map back to a 3D point.
You can use Yasutaka Furukawa's "CMVS" or "PMVS2" software to do this. Or if you want to experiment by yourself, openCV is a open-source computer vision toolbox to do many of the sub-tasks required for this.
This can be done with two webcams in the same ways your eyes work. It is called stereoscopic vision.
Have a look at this:
http://opencv.willowgarage.com/documentation/camera_calibration_and_3d_reconstruction.html
An affordable alternative to get 3D data would be the Kinect camera system.
Maybe not the answer you are hoping for but Microsoft's Kinect is doing that exact thing, there are some open source drivers out there that allow you to connect it to your windows/linux box.
School going kids wear a certain uniform on respective days within a week.
(e.g. for boys = White half pant, white shirt, tie of a certain color, belt ..)
(e.g. for girls = blue checked frock, navy blue pinafore, black shoes with navy blue socks and belt). They will have different variations to wear on different days.
What would be a good way to show such information in the user interface for boys / girls. Can you point me to any sites which depict such information very clearly.
Show the uniforms graphically through images of a boy and a girl wearing the correct uniform for the selected day of the week. If you want to go all out, you could have 360 degree views (spinnable by mouse/gesture) for the boy and girl.
How about this kind of table, replace smiley's with uniform images and Description of the uniform below that.
Photo and text. It's absolutely enough for parents. May be not enough for designer...
It seems to me to be over-complicated to have a "uniform" that changes on a daily basis, to the point that you require an app which informs people what to wear. But given the requirements, I'd simply show the list of items for each day.
If, for example, there are only a couple combinations, I'd give each combination a name and put the combination name on the calendar. Then I'd make the name itself a link to further information about it, including the detailed list of clothes and pictures of each item. Perhaps a picture of a model wearing the clothes but that might not be necessary.
If the uniform varies a lot, such that enumerating the combinations is impractical or impossible, I'd show the full list (with pictures) for each day.
Aside, is this an actual requirement for a real school? My high-school had a uniform and it wasn't nearly so complicated. There was just a list of allowable/required elements and it was distributed to the parents before the start of the school year. Most of the time the rules could be stated in a couple sentences, such as "From the start of the school year until October 1st, and from Easter until the end of the school year, the 'Summer Uniform' may be worn; the rest of the school year only the standard uniform is permissible. The standard uniform is ... for boys and ... for girls.' This certainly was straightforward enough that there was never any serious question, and if there was a problem the teachers would simply inform the students that they were "out of uniform".