Latest Contributions by RobertoFilloramo

‎06-22-2019

Sample data from Roberto Filloramo's "Focal statistics problem values" question

‎06-21-2019

I am afraid that, as you said, the 0 represents the nodata. Also in the histogram is reported the lowest value as 0 (see fig.). So the data has been stored like this, although not being at the sea level (it is an area of northern Germany).

‎06-21-2019

Well, the file is a DGM and the csv file (forming the tiles) containing just x, y and z information. Unfortunately, the site from which I downloaded the files didn't say anything about nodata and the only data, about min and max values that I have, are those given by the raster value scale in the layer panel (as in the previous fig.). That's the problem.

‎06-21-2019

Concerning the "nodata value in the input rasters set", I meant the "ignore_nodata" set (optional) in the focal st. window tool. Regarding the "...05.tif" file, it showed no nodata, as you can see in the fig. Therefore, according to what you wrote the nodata lack in the input file ("...05.tif") may be the problem, at this point. In order to get a smoother surface, how could I solve this issue? I wanted a smoother surface to use it as input for the least cost path analysis, in order to avoid that the process could take into account small and medium surface variations/modern structures (such as a street or a roundabout) during the path estimation.

‎06-21-2019

Thank you Lance Cole‌ and Dan Patterson‌ for your response. As suggested I tried to compare the focal st. results ignoring the NODATA, but in both cases the values were bigger than the input raster (see fig. "FocalSt_IgnorNoData" stands for the Ignore NoData flagged option, contrary to "FocalSt_NoData"). For what concerns the holes/voids, I used the Fill tool. The output raster had bigger values (see fig.), I presumed because of the filling operation, but using the new output for the focal st. I noticed the same problem (see fig.). I am just wondering now if the problem is since the raster file "ALS_Erwitte_geotif_05m.tif" was generated in CouldCompare using nearly 8 get-together tiles. Each tile was represented by a .csv containing the coordinates points of the entire area. What do you think? Thank you!

‎06-20-2019

Hi, I am using ArcGIS 10.1 and I am working with the Focal Statistics tool in order to get a smoother surface (I set "neighborhood rectangle 3x3 cell units" and as statistics type "mean"). The obtained result it looks like not so fine since the focal st. values seem increased respect to the input raster (see figures), but I don't understand the reason. The doubt arose making some comparison with other results in which the focal st. raster values are smaller than the input raster. Could someone help me? Thank you

‎01-16-2019

Hi, I use ArcGIS 10.1 and I am dealing with viewshed and least cost path analysis, I would like to generate a path on the base of a cost surface taking into account the viewshed data as indicated into the paper "On applying viewshed analysis for determining least-cost paths on Digital Elevation Models" by Stucky and Lee. In order to do that the authors say: "To support the computation of the various least-cost paths discussed in this paper, two grids of visibility information should be calculated. The first is a general viewgrid (VG) that records for each cell the number of cells visible. The second is a dominance viewgrid (VD) that holds for each cell the number of cells from which the cell is visible. Both grids are constructed by calculating intervisibility between grid cells using the LoS algorithm. Two matrices are not equal because the number of cells visible from a cell does not always equal the number of cells to which that cell is visible. Next, these two visibility grids are converted to friction surfaces. These surfaces are used as the input grids to the least-cost path procedure. To do this, a few adjustments must be made to create the friction surfaces suitable for calculating viewpaths that we wish to use. For this study, we have implemented a total of four viewpaths. Each of the four viewpaths requires different friction surfaces to be setup from viewgrids." Does someone know how to create the viewgrids and covert them in friction surfaces? Thank you in advance

‎11-13-2018

Sorry I forgot to write before... the parameters are OFFSETA 1,65; OFFSETB 1,65; RADIUS2 15km. Anyway, in arcmap 10.1 there is just the viewshed tool (not viewshed 2). Therefore, I applied the combine tool to the viewshed results, since I used a tool planned for acquired the fuzzy viewshed I thought that perhaps my parameters were considered more in the viewshed result then in the fuzzy one. I presume that it works, as in the viewshed 2 sample that you posted.

‎11-13-2018

Thank you Dan for replying me... So, I worked around with the Combine tool, to be honest it is not very clear to me (also from the Esri's Help about it). Attached you will find the result, I used the tool for the fuzzy viewshed applied to the green point (triangles). If the table should show the overlapping area, I believe that the result is wrong. Concerning the percentage, I agree with you on the "number relative to a total" yet the viewshed and fuzzy viewshed are 0 and 1 or on the scale from 0 to 1 (as in the figure below).

‎11-12-2018

Hi, I am working with ArcGIS 10.1, I determined the viewshed and the fuzzy viewshed for 10 points placed along a river, my willing is to create a statistics (table or graph), using the results, in which it is possibile to see the percentage of overlapping between the visible area (according each point) and the percentage of visibility for each point according the landscape in all cardinal points. Is it possible? Any suggestions? Thank you

‎10-19-2018

Thank you Dan!

‎10-19-2018

Hi, I am having some troubles with my ArcMap (v. 10.1), suddenly it started to crash. Firstly it crashed just opening my projects, then after few days it was able to open them yet crashed when I tried to select some .shp or raster or dwg. While now it is able to charge the project, select the .shp or raster or dwg yet if I try to use the editor tool (when I select a point, for instance, in order to use "move to"). Moreover, if I use another tool it takes some second (such freezing) before using it... Does anyone have some suggestions? Thank you

‎09-23-2018

yes, sorry... I wrote wrongly, I meant if I cleared the caches I could have problems with the data displayed since they couldn't find their possible caches. Anyway thanks

‎09-23-2018

Thanks Dan for replying me... Just a question because it is not so clear to me: if I cleared my caches, could I have some problem with my project? Since the cache files are linked to the project. Anyway the "display cache" tab showed me a value of 1,48 Gb.

‎09-22-2018

Hi, I am using ArcGIS 10.1 and in these last weeks I had a problem with the find tool, every time that I try to open the tool it takes a lot of time (such 5/10 min). In some cases I have to force the closing (because it seems really blocked) and reopen ArcMap, yet with the same result. Could someone know how to get a solution? Thank you

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Latest Contributions by RobertoFilloramo

Sample_Data.zip

Re: Focal statistics problem values

Re: Focal statistics problem values

Re: Focal statistics problem values

Re: Focal statistics problem values

Focal statistics problem values

Generating a least cost path from visibility data

Re: Viewshed Analysis and Statistics

Re: Viewshed Analysis and Statistics

Viewshed Analysis and Statistics

Re: ArcMap crashing issues

ArcMap crashing issues

Re: ArcGIS 10.1 Find tool problem

Re: ArcGIS 10.1 Find tool problem

ArcGIS 10.1 Find tool problem

Re: Path Distance problem

Re: How to exlude raster cell from the cost surfac...