Latest Contributions by KateBallard

I actually figured this one out, what happened was: on a clip I created of my study area, I believe I let it set the nodata values as 255 (the ArcGIS default). Although for some reason this did not show up under properties when I looked afterwards. When I redid the clip and told it to assign 0 to nodata values, redid the extract by attributes tool creating a new raster for each landcover type (from this new clip), then redid the zonal statistics tool, it came out correctly with no negative values. So, what was happening was, since numbers were assigned for each landcover type (for ex: water =11) the sum was calculated by 11+11+11+11... and so on.   However, with nodata pixels set to 255, cells that were not water were calculated as 255. So the tool was doing 11-255+11-255... By redoing all those steps and changing the nodata pixels to 0 in the original clip, the tool calculated sum by doing 11-0+11-0 .... I still don't know why it only did the 11-255+11-255 thing for some zones and not others, but my fix seems to have worked for all zones.  Also, to answer your question, I wanted to see if I could make this tool work rather than performing a join with the vector layer because it allows me to show which pixels (that appear split by a county line) were counted in which county zone. Also keeping it in raster rather than vector will become helpful later in my analysis I believe.    HOWEVER, now I am running into a different issue. After I fixed the problem above, I started running the zonal statistics tool on each extracted landcover type raster (so one for the water raster, one for the deciduous forest raster and etc). It worked perfectly on the first 4 landcover types. Then, without changing anything, when I was on the 5th landcover type, the zonal statistics tool crashed and gave me the generic 999999 Error. It also gave me an error that said "no current record", and I am not sure what that means exactly. I am particularly confused because I changed nothing between when it worked and when it crashed. I was just sitting next to the computer taking notes on paper, then each time the tool finished I would just set it up and press go for the next landcover type.    So, to troubleshoot I tried it on a landcover raster that the tool had previously worked on moments before (exact same input raster, zones and everything) and the tool crashed and gave me the same errors. So I am completely confused why the tool worked one moment and crashed the next, even when I tried to re-run it on an input raster that worked less than an hour before. Do you have any idea why this would happen?    Thank you for all your help, I really appreciate it.  ... View more

Oh I see. So, that means that a cell "split" by a county line will only be counted in the sum of one of the counties and not both, because the center can only fall inside one county (zone)?  ... View more

I will do that! I have one more question if you don't mind, I want to tell the Zonal Stat tool to only count cells that are completely inside a county, not ones that are only half inside a county (in other words exclude raster cells in the SUM that are split by the county boundary line). However, I do not see an option for this in the Zonal Stat tool window. Do you have any idea how I could accomplish this?  ... View more

Sorry, I don't think I explained very well. I actually got the tool to work (summing for each individual county) by just associating it with a code in the shapefile that was unique to each county. My issue is that in the raster there are different types of cells (blue cells = water (11), dark green cells = evergreen forests (42) and etc). I basically am using the Zonal Statistics as Table tool to tell me how many water cells there are in each county, how many evergreen forest cells in each county and so on. So far, the only way that I can find to have it sum water cells and evergreen forest individually, rather than just summing all cells in each county, is to first use "Extract by Attributes" to make an individual raster for each landcover type (so a raster showing only water cells, a raster showing only evergreen forest cells, etc..) Then running the Zonal Stat as table tool on each one of these separately. I'm wondering if there is an add-on or other tool that would allow me to tell the Zonal statistic tool to sum by cell type? Unfortunately I'm not trained in Python.  My other question is, I want to tell the Zonal Stat tool to only count cells that are completely inside a county, not ones that are only half inside a county (like the cell is split by the county boundary so only half the cell falls in the county). However, I do not see an option for this in the Zonal Stat tool window. Does anyone know a way that I could accomplish this?  Thank you! ... View more

Yes I did exactly that, shortening file names and making the join permanent by exporting it to a new feature class, except I kept it on the outside server in the same folder as the main map, and the tool luckily still worked. Thank you!  ... View more

Thank you all for the help! It's working now. It seems the length of the filenames and the joined table were the problems.  It appears that I cannot run the Zonal Statistics as table tool and have it sum up each cell type individually (for example number of deciduous cells in each county, number of coniferous cells etc in each county). Instead it just seems to sum all the cells together.  The only fix I know for this is to run Extract by Attributes for each cell type (which takes a very long time), then performing the Zonal Statistics tool on each one. Does anyone know of a tool that could allow me to do this in a more efficient way, or to select that I want a sum of each type of cell individually?  Thank you! ... View more

- I went back and changed the file names to have "_" instead of spaces, the one you see is just me having edited the name in properties to be more readable.  - Yes, I joined tables together to match my Lyme disease case numbers with the county shapefiles, is that a problem for trying to perform a zonal statistic? If so, how should I go about fixing this and getting the Lyme case data and population data matched with the shapefile? - No its not from esri, the input value raster was downloaded from the National Land Cover Database (NLCD).  - Yes, the Z folder is a server that I am doing all of this work on because I am working on a university computer, is that a problem for this tool? I can move it to the computer and then move it back to the server before I shut down the computer. Will that cause any issues or just involve restoring the pathnames?  - I tried the normal (non-table) Zonal Statistics tool on one county, and it just gave me a black box over the area. I assume that means the tool didn't work. I also tried the Zonal table tool on just one of the cell types, and that also didn't work.  Thank you for all your help!  ... View more

Yes I did. Now Im just having that issue where the graded colors only show up for the first year. ... View more

Thank you! I can't believe I missed that. Now that I got that to work, the graded colors are only showing up for the first year (2000) in the time slider. It definitely can tell the difference between the year's data because the 2000 map here on the time slider matches my original year 2000 map. I tried to flip through the time slider and set the symbology for each year, but that did not work. Do you have any idea what I could do to solve this problem?  ... View more

I cant use classes anymore, because of the new way the data is organized and that there are 15 years worth of data for each county instead of 1 (which was the case when I successfully made the first one for 2015). Now, I have to use "Unique values" under "Categories" instead of "Graded colors" under "Quantities" (under graded colors now the value options just say 'none'). Because of this now, I dont have the option to create classes (shown in the last photo). I am wondering how to either make the values work again under "graded colors" so that I can use the classes option and make them into ranges, or make this all work that way under "categories". The issue is just that now the data has been transposed, so instead of me having individual maps where each one just had a field called Cases2015 or Cases 2014, and etc with each corresponded to a county, now, there is one field called years which contains all the years and then a column for counties, but instead of there being a single county row and then case # values under each year, each county has a row for every year. So, for example, there will be a row for Weston county in 2015 with the number of cases that year, Weston in 2014 with the number for that year and so on, as shown in the first picture.  ... View more

They range from 0 to around 1000. The problem is that when I try to create a graded color scale, I instead get something that looks like the photo I just added to my original post, and it does not let me create "ranges" to symbolize certain colors like I did before the data table was transposed. For example 0=lightest, 1-25 =light purple, ..... 700-1000=darkest.  ... View more