StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POLatitude/longtitude conversion to image x/y coordinates (Miller Cylindrical projection)
primarykey
Id
9318429
data
AcceptedAnswerId
9318868
AnswerCount
1
ClosedDate
CommentCount
5
CommunityOwnedDate
CreationDate
2012-02-16T20:17:11.930
FavoriteCount
1
LastActivityDate
2012-02-17T18:57:56.007
LastEditDate
2012-02-17T18:57:56.007
LastEditorUserId
531388
OwnerUserId
531388
ParentId
0
PostTypeId
1
Score
3
ViewCount
3244
LastEditorDisplayName
text
Body
As already said in the title, I need some help with converting lat/long to x/y coords in Miller Cylindrical projection. I`m currently writing an app (in Java) which gets city list as an input and then gets lat/long for each city from Yahoo Placefinder. I used <a href="http://mathworld.wolfram.com/MillerCylindricalProjection.html" rel="nofollow">these</a> formulas in my code. <a href="http://img29.imageshack.us/img29/6572/99432143.png" rel="nofollow">Here is an example</a> of what I get. (image is for the reference only, not the one I use). As you can see the X positions are only a few pixels (2-3) off, this can be a problem with my calculations of prime meridian shift (CENTRAL_MERIDIAN_OFFSET) in this map. But the main problem is incorrect Y coordinates. Here is my code (updated - 34px compensation for equator offset): <pre><code>public final double W = 6343; public final double H = 4767 - 34; protected Point toMillerXY(double lon, double lat) { double x, y; lon = Utils.degToRad(lon); lat = Utils.degToRad(lat); x = lon - CENTRAL_MERIDIAN_OFFSET; y = 1.25 * Math.log( Math.tan( 0.25 * Math.PI + 0.4 * lat ) ); x = ( W / 2 ) + ( W / (2 * Math.PI) ) * x; y = ( H / 2 ) - ( H / ( 2 * 2.303412543 ) ) * y; y += 34; return new Point(x, y); } Output: Fetching data with: http://where.yahooapis.com/geocode?location=Buenos+Aires,Argentina Latitude: -34.608521, longitude: -58.373539 --- Fetching data with: http://where.yahooapis.com/geocode?location=Tokyo,Japan Latitude: 35.670479, longitude: 139.740921 --- Fetching data with: http://where.yahooapis.com/geocode?location=Cape+Town,CAR Latitude: -33.919060, longitude: 18.421961 --- Fetching data with: http://where.yahooapis.com/geocode?location=Rome,Italy Latitude: 41.903110, longitude: 12.495760 --- Total cities: 4 Result for Buenos Aires: 1964.598428, 3046.740995 Result for Tokyo: 5455.265150, 1732.669551 Result for Cape Town: 3317.692474, 3032.814395 Result for Rome: 3213.276105, 1602.176163 </code></pre> Obviously, something is wrong with Y coord calculation. I`m not sure whether 5.6 should really be the right value but the vertical range of Millers projection was said to be -2.3..+2.3 in one of the references I read so I used it.
Tags
<latitude-longitude><map-projections>
Title
Latitude/longtitude conversion to image x/y coordinates (Miller Cylindrical projection)
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. USVarnius
UserOwnerUserId
1. USVarnius
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 POLatitude/longtitude conversion to image x/y coordinates (Miller Cylindrical projection)
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
2. VO
 singulars
 PostPostId
 POLatitude/longtitude conversion to image x/y coordinates (Miller Cylindrical projection)
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
3. VO
 singulars
 PostPostId
 POLatitude/longtitude conversion to image x/y coordinates (Miller Cylindrical projection)
 UserUserId
 USDavid Chien
 VoteTypeVoteTypeId
 VTFavorite
CommentsPostId

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.