Re^5: Permutation and comparison loop

Aye. However, your example image isn't exactly representative of what his coordinates would define, which would be two adjacent pie slices instead of a full rectangle. I doubt that his data would work that way, but yes anything is possible.

Your solution of breaking up the wierd region would work though, yes. For MaxLong > 90

MinLat, MaxLat, MinLong, MaxLong
[download]

MinLat, MaxLat, MinLon, 90

# and

(MinLat+180)%360, (MaxLat+180)%360, 180-MaxLong, 90
[download]

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Re^6: Permutation and comparison loop by BrowserUk (Patriarch) on Apr 21, 2011 at 15:21 UTC
However, your example image isn't exactly representative of what his coordinates would define, which would be two adjacent pie slices instead of a full rectangle That really depends upon whether the imagery in question is raw sat data or post-processed. CCDs don't adjust their shape with reference to the 'latitude' of their current position. Ie. The images they take a always rectangular. Hence the reason why images of the poles (of earth or other planets) are often made up of composites of lots of frames that are all rectangular, but overlay each other at weird angles. Like this one of the Martian South Pole. The poles are (can be) imaged on every orbit, each time at a slightly different angle as the orbit precesses. Whether the positioning of (the corners of) such images are given in lat/long or some other perhaps spherical coordinate system I don't know. But given that the OP mentions 0 - 360 longitude rather than the more usual -180/0/+180 used by mapping (and GPS?), assuming that the image coordinates have been converted into a Mercator-like system seems unlikely. ...%360 You have to be careful using modulus on float data, it integerises: `print +(123.456 + 180 )%360;; 303` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]

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Re^6: Permutation and comparison loop
by BrowserUk (Patriarch) on Apr 21, 2011 at 15:21 UTC

However, your example image isn't exactly representative of what his coordinates would define, which would be two adjacent pie slices instead of a full rectangle

That really depends upon whether the imagery in question is raw sat data or post-processed.

CCDs don't adjust their shape with reference to the 'latitude' of their current position. Ie. The images they take a always rectangular. Hence the reason why images of the poles (of earth or other planets) are often made up of composites of lots of frames that are all rectangular, but overlay each other at weird angles. Like this one of the Martian South Pole.

The poles are (can be) imaged on every orbit, each time at a slightly different angle as the orbit precesses. Whether the positioning of (the corners of) such images are given in lat/long or some other perhaps spherical coordinate system I don't know. But given that the OP mentions 0 - 360 longitude rather than the more usual -180/0/+180 used by mapping (and GPS?), assuming that the image coordinates have been converted into a Mercator-like system seems unlikely.

...%360

You have to be careful using modulus on float data, it integerises:

print +(123.456 + 180 )%360;;
303
[download]

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

[reply]
[d/l]