Timeline for How do I iterate through every cell in a continuous raster?
Current License: CC BY-SA 3.0
36 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 13, 2017 at 12:33 | history | edited | CommunityBot |
replaced http://gis.stackexchange.com/ with https://gis.stackexchange.com/
|
|
| Sep 29, 2013 at 20:36 | vote | accept | Conor | ||
| Sep 29, 2013 at 18:26 | vote | accept | Conor | ||
| Sep 29, 2013 at 20:36 | |||||
| S Sep 29, 2013 at 18:26 | history | bounty ended | Conor | ||
| S Sep 29, 2013 at 18:26 | history | notice removed | Conor | ||
| Sep 29, 2013 at 8:18 | answer | added | Antonio Falciano | timeline score: 2 | |
| Sep 26, 2013 at 22:16 | history | edited | Conor |
edited tags
|
|
| Sep 26, 2013 at 21:33 | answer | added | asonnenschein | timeline score: 12 | |
| Sep 26, 2013 at 20:44 | answer | added | SamEPA | timeline score: 10 | |
| Sep 25, 2013 at 22:52 | answer | added | Conor | timeline score: 3 | |
| Sep 25, 2013 at 19:20 | comment | added | Conor | @PetrKrebs Could you expand on these samples? They don't seem very clear to me about what it is they are doing. What is an IPixelBlock? From the links you provided it seems like it is a subset of a full raster dataset consisting of multiple pixels. Is there a limitation on the amount of pixels in one IPixelBlock? Is using IPixelBlock necessary to loop over a raster? How does SafeArray work? There is very little ESRI documentation on these describing what they do and as such it is difficult to define the steps necessary to access single pixel values. | |
| Sep 24, 2013 at 22:28 | history | edited | Conor |
Added arcgis-10.0 tag.
|
|
| Sep 24, 2013 at 19:15 | comment | added | Petr Krebs | Do any of these two samples help? How to access pixel data using the RawBlocks object and How to access pixel data using a raster cursor . I think both are quite clear and illustrational. | |
| Sep 24, 2013 at 18:20 | history | tweeted | twitter.com/#!/StackGIS/status/382570243576856576 | ||
| S Sep 24, 2013 at 17:45 | history | bounty started | Conor | ||
| S Sep 24, 2013 at 17:45 | history | notice added | Conor | Draw attention | |
| Sep 24, 2013 at 14:19 | answer | added | Hornbydd | timeline score: 5 | |
| Sep 24, 2013 at 1:23 | history | edited | Conor | CC BY-SA 3.0 |
added 9 characters in body; Post Made Community Wiki
|
| Sep 24, 2013 at 1:03 | history | edited | Conor | CC BY-SA 3.0 |
added 244 characters in body
|
| Sep 24, 2013 at 0:55 | history | edited | Conor | CC BY-SA 3.0 |
added 244 characters in body
|
| Sep 24, 2013 at 0:51 | comment | added | Conor | The final cell value would be 1 because R2C2 (value 10) is equal to R2C3 (also value 10), R3C2 (also value 10), and R3C3 (also value 10) (see condition #5). My output raster needs only two values 0 (not edge) and 1 (edge). If ANY of the 5 conditions return true, the final output should be 1. Only if NONE of the five conditions return true should the final output be 0 for the cell. | |
| Sep 23, 2013 at 23:26 | comment | added | Hornbydd | Conor could you clarify what your expected final value would be for the central cell following your above sequence of rules for the scenario 3x3 grid where R1 is top row, R2 is middle and R3 is bottom: R1 = 1_3_6, R2 = 8_10_10, R3 = 5_10_10. They are numbers I just made up but I am unsure what the final value would be as this scenario has values that are greater and equal? | |
| Sep 23, 2013 at 20:48 | history | edited | Conor | CC BY-SA 3.0 |
added 102 characters in body
|
| Sep 23, 2013 at 19:05 | history | edited | Conor | CC BY-SA 3.0 |
deleted 5 characters in body
|
| Sep 23, 2013 at 17:51 | history | edited | Conor | CC BY-SA 3.0 |
added 45 characters in body
|
| Sep 23, 2013 at 17:25 | history | edited | Conor | CC BY-SA 3.0 |
added 29 characters in body
|
| Sep 23, 2013 at 17:18 | history | edited | Conor | CC BY-SA 3.0 |
added 29 characters in body
|
| Sep 23, 2013 at 17:06 | history | edited | Conor | CC BY-SA 3.0 |
added 134 characters in body; edited title
|
| Sep 23, 2013 at 16:57 | comment | added | Conor | @whuber It is for edge detection operations to create vector polygons from my raster. The application is conceptually similar to identifying hydrology basins from a DEM (think of the center cell in the neighborhood statistics listed above as the "peak" that water would flow downslope from) but is outside the field of hydrology. I have previously been using Flow Direction and Basin Rasters for this purpose, but those are prone to error in my final analysis due to the properties of these methods not being exactly what I need. | |
| Sep 23, 2013 at 16:31 | comment | added | whuber | Thank you for the clarification, Conor. I agree that if your GIS incurs substantial overhead for each raster calculation, writing your own loop may be more efficient. Out of curiosity, what is the intended interpretation of this (unusual) set of conditions? | |
| Sep 23, 2013 at 16:21 | comment | added | Conor | @Luke I have added details of the analysis. | |
| Sep 23, 2013 at 16:18 | history | edited | Conor | CC BY-SA 3.0 |
Added details of analysis
|
| Sep 23, 2013 at 15:04 | comment | added | whuber | @Luke is correct: by far the best way to perform an iterative raster calculation in any GIS is to avoid explicitly looping through the cells, because under the hood any looping that has to be done has already been optimized. Instead, seek a way to use the map algebra functionality provided by the GIS, if that's at all possible. If you were to describe your analysis you might obtain useful answers that use such an approach. | |
| Sep 23, 2013 at 1:43 | comment | added | user2856 | It is nearly always unecessary to to loop through every cell in a raster. Can you provide more information about what you are trying to do? | |
| Sep 23, 2013 at 1:40 | answer | added | artwork21 | timeline score: 4 | |
| Sep 22, 2013 at 17:44 | history | asked | Conor | CC BY-SA 3.0 |