Latest Contributions by ChenaySimms

‎02-23-2015

Hi Xander The protected area we are working in has seen a relatively large number of animal mortalities due to fighting. This study is trying to work out the cause of this (too high population densities, competition for resources…..) We are thus trying to get a reliable density map that will eventually feed into a landscape and social analysis. Thanks

‎02-23-2015

Thanks for your comments, I will definitely look further into that aspect of it 🙂 I have a statistician helping with the analysis, I was just hoping that this data would lend itself to a more spatially based analysis.

‎02-23-2015

Hi Xander I have not finished my data cleaning yet hence the discrepancies. Some of the later data was captured using GPS's which resulted in some points not following the grid pattern. Also some observers used more/less decimals in the grid coordinates when recording the sightings hence the slight shift in some of the observations 😞 Thanks for the inputs

‎02-23-2015

Sorry 🙂 Included here is the point data as well as the results of an identify of one of the points (you can see that this one point has 73 records associated with it). Below that is a quick density map using all the points with the roads overlayed on it. There roads to the south and west are the most frequently used roads whilst the roads to the east are used fairly infrequently. There seems to be a correlation between them and animal densities...... There is also some terrain bias but at first glance it is not as influential.

‎02-23-2015

Hi Dan No, the records are captured as points. The reserve was divided into a reference grid of 1 * 1km cells that were used to assign a location to the sightings (so one location was given to all the sightings within that grid). I had thought of transforming the points to a raster but there are too many variables in the attribute table that I need to keep. Thanks Chenay

‎02-23-2015

Hi all I have old animal sightings data that I want to analyse for distribution, frequency and landscape utilization. However the data was captured using a grid system where all animals seen within a specific grid cell get assigned the coordinate of the bottom left corner of the cell. The area is fairly mountainous and there seems to be a strong bias towards grid cells with roads through them. Is there a way to quantify and or remove this bias? Any suggestions would be welcome. Regards Chenay

‎11-29-2013

Hi Neil Thanks, this worked like a charm. Maybe you can also help me with my next step. I now need to take my clean datasets and find the average pixel value for each pixel across the set of rasters. My final output is a raster that show the average EVI value for each pixel for the year. I have previously done this as an Excel exersise but I am sure there are better ways of doing this. As far as I can tell there is no tool for such an anlysis and would need to be a python script..... Any help would be appreciated. regards Chenay

‎11-27-2013

Hi guys Thanks, this will do the trick as my raster was not an integer. However, as I have a few hundred rasters that I need to analyse is there a way to automatically do the % calculations out of the attribute tables? Thanks again Chenay

‎11-27-2013

Hi Thanks, forgot about the SETNULL tool, that will definately make life easier 🙂 I did sort my problem out, I added an extension to the end of the output and now at least the model runs. As for the expression, it gave the correct results when I ran it on a single raster. I double checked it agains the info in the Help and the syntax I have used is the same as that given in the Help. The model outputs that I have spot checked also seem correct. Thanks again for the help. regards Chenay

‎11-27-2013

Hi guys Does anyone have an idea of how to go about calculating the percentage of NODATA pixels within a image? I need to be able to add the method to a model. Thanks 🙂

‎11-27-2013

Hello I am trying to use the SETNULL funtion in the raster calculator to convert all my minus values to NODATA. As I need to run this analysis on a large number of EVI images I have tried to put it in a model with an iterator but it runs into the following error - ERROR 000539: Error running expression: rcexec() Traceback (most recent call last): File "<expression>", line 1, in <module> File "<string>", line 8, in rcexec RuntimeError: ERROR 010093: Output raster format UNKNOWN is unsupported. Failed to execute (Raster Calculator). On a single raster my SETNULL expression works so this has got to do with my use of the iterator output in the expression. Expression = SetNull("%MCD43_EVI_interpolated_SA_2000049.tif%" < 0,"%MCD43_EVI_interpolated_SA_2000049.tif%") Output = %Name%_c Any ideas? Thanks Chenay

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Date Last Visited	‎11-11-2020 02:23 AM

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Latest Contributions by ChenaySimms

Re: How to remove observer bias from grid based observations

Re: How to remove observer bias from grid based observations

Re: How to remove observer bias from grid based observations

Re: How to remove observer bias from grid based observations

Re: How to remove observer bias from grid based observations

How to remove observer bias from grid based observations

Re: Calculate percentage of NODATA pixels in a scene

Re: Calculate percentage of NODATA pixels in a scene

Re: Iterate rasters into SETNULL giving error

Calculate percentage of NODATA pixels in a scene

Iterate rasters into SETNULL giving error