Questions tagged [statistics]

Collecting and analyzing numerical data or making numerical summaries of data.

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votes
3answers
246 views

How to show statistically significant incident locations

First let me preface with I tried to search for this solution first but I don't really know how to word it and could not find any results so excuse me if this is a duplicate. I would like to know how ...
1
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0answers
39 views

Statistical bias arising out of only comparing US census block groups that have not changed (been split) over time?

Census Block Group ("CBG") study areas are notorious for changing over time. Even from 2009 to 2013, about 10-25% of the CBG's in South Carolina have not remained consistent over that time. Seeing ...
25
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3answers
4k views

Major bug in ArcGIS Zonal statistics?

Update: The bug has been fixed in the ArcGIS 10.4 release I am using ArcGIS 10.2.2 to determine zonal statistics for a number of zones. If there is any NoData in the value raster, I want the zone ...
1
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0answers
103 views

Raster Area within a Polygon

using ArcGIS, I have a layer of overlapping polygons and a raster grid underneath. The raster is not a continuous grid - the cells are spread out. I simply need to calculate the total area of the ...
5
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1answer
303 views

Index express the similarity in shape between two data sets

I have two data sets. One is points in the blue curve. The other is points in the green curve. Now I want to find a property (P) or something else like index that has the following characteristics: ...
1
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0answers
693 views

Invalid drop item: Calculate statistics

I have a number of rasters that I need to calculate histograms for. These are continuous rasters from 0 to 294.208 - many decimal places. I need to be able to classify the histogram down to at least ...
4
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2answers
4k views

How to sum pixel values of a floating point raster in ArcMap?

I have a floating point raster with values from 60 up to 95 (with decimals), it has 7077 pixels of 250x250m size. Is there a way to sum all pixel values of this raster? For example, if the raster had ...
0
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1answer
316 views

Where can I find geodata for the Russian терсон-мо or терсон-ате census units? Or: can osm_admin polygons be linked to those?

I'm looking to combine Russian census data with georeferenced polygons. This is for a research project looking into different aspects of mobility within the Republic of Саха (Sakha/Yakutsk), the ...
2
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0answers
173 views

Zonal statistics error: 0-d arrays can't be indexed

How can I fix the error 0-d arrays can't be indexed? This message appears after the tentative to use the algorithm Qgis Zonal Statistics. Detail: the algorithm worked very well several times and then ...
2
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1answer
98 views

How to get the upstream average of a raster data layer that falls into a river network?

I have a raster layer of a network of rivers and a raster layer of data I want to extract. For each pixel of the rivers, I need to know the upstream average of the data layer that falls into the ...
1
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1answer
1k views

How do I Calculate Grouped Percentiles or Batch percentiles in ArcMap?

My question is similar to this one which was answered successfully: Calculating Percentiles in ArcMap? My addition is how do I batch this solution for multiple files or apply a group-by feature to ...
2
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0answers
149 views

Some output cells show up as noData in ArcMap Block Statistics? [closed]

I am using ArcMap 10.2.2, and I need to aggregate categorical data from 30m up to 90m and 900m resolution for species distribution modeling. The algorithms available in resample (nearest neighbor, ...
2
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1answer
5k views

Calculating raster statistics for each band in QGIS?

i need to calculate raster statistics for RGBN (4 channels, multiband image) rasters in QGIS. In Arcgis if you use "calculate statistics" in ArcCatalog, statistics are calculated for every image ...
-1
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1answer
213 views

Counting points in concentric circle buffer zones of different sites in a map? [closed]

I produce concentric circles of 200 and 500 m buffer zones to see water points within each buffer zones. The buffer zones are created throughout my study area. How can I count the points found in ...
2
votes
1answer
494 views

Accessing bands in .pix (PCIDSK) file in python/arcpy

I am trying to perform zonal statistics on a single band from a multi-band raster in .pix format. I have things working great with a tiff file. I am able to access the bands using this code: desc = ...
0
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1answer
1k views

Zonal Statistics as Table output is missing some polygons ONLY when run from Python script

I have a raster file from which I am attempting to calculate mean values for polygons defined in a shapefile. Using the Zonal Statistics as Table tool from within ArcGIS works great. My shapefile ...
1
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1answer
933 views

Unit of measurement from standard error prediction map?

I am performing an ordinary kriging analysis and came out with the prediction standard error map. I would like to know the units of such map. Can anyone help?
2
votes
1answer
2k views

How to calculate RMSE of geographic coordinates?

I've been working on my project and I stumble upon how I can calculate the Root Mean Square Error (RMSE) of geographic coordinates. What I have is a derived coordinates from processing LiDAR data ...
0
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1answer
30 views

Need statistics from US census [closed]

I am not sure if this is the right place to ask, if so please recommend a stackexchange, I am having a lot of issues getting the data approximations that I need for a report. I am looking for the ...
1
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1answer
2k views

Extract values from raster by using polygons

I am working with multiple raster files that cover all of united states. The file format of the rasters - GeoTIFF. I have around 100 geotiffs that I need to process. Then I have another shapefile with ...
2
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1answer
302 views

QGIS equivalent to MapInfo Sum Attributes for selected vector objects?

I´m looking for QGIS equivalent to the basic MapInfo tool "Sum Attributes". I´ll explain what it does: For selected objects in a vector layer, a popup window shows basic statistics such as: - Sum ...
1
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1answer
77 views

Can I no longer see my view counts in the new dashboard?

The inset graphic shows the relative up and down of each day's views, but I can't see any numbers. I'd love to continue tracking my monthly stats.
2
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1answer
406 views

Disaggregating vector layer splits

I'm fairly new to GIS, but I've got the basics down. I'm utilizing QGIS and Python to calculate election statistics by legislative and congressional districts. I'm trying to aggregate precinct level ...
1
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1answer
250 views

Proof low deviations in DEM compared to point dataset

I am not sure how to achieve the following consistently: I have a regular distributed point dataset (surface elevations). From this I derived several DEM using QGIS IDW Interpolation method. Now I ...
0
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0answers
146 views

Overlay polygons on raster in different projections

I'm overlaying polygons on a raster to get the average value inside the polygon (using SAGA->Shapes-Grid->Add grid values to shapes in the QGIS Processing Toolbox), using a geographic and a ...
3
votes
1answer
162 views

Memory issues with zonal statistics

I have got a memory issue due to the use of the zonal statistics command into a loop. It seems that after using the ZS command QGIS stores some information in the RAM (cache memory?). It is not ...
8
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1answer
5k views

Calculating area weighted average of attribute in one layer by shape in another using ArcGIS for Desktop?

For a project I am working on I would like to intersect fire station response districts with income data to determine the median income per response district. However the borders of the layers ...
1
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0answers
219 views

IDL 7.1.2; How to plot negative correlation in Taylor diagram [closed]

I am working on a model's run performance evaluation, three runs of GFDL-CM2.0 and five runs of GFDL-CM2.1 are used for temperature and precipitation for the years 1979-2000. The objective is to ...
3
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1answer
275 views

Creating grid with statistics of merged shapefiles in QGIS?

I operate with QGIS. I have to split the shape files of the buildings and the roads of a city into a grid of 500x500m per square and into each square I have to obtain the total free area, the total ...
2
votes
1answer
1k views

How to calculate the number of points with differing characteristic in a polygon in ArcMap?

I have a .csv (exported to .shp) database with about two thousand entries of points. One column in this database has certain values (e.g. a point can be 'ash tree', 'beech tree', 'elm tree', etc). I ...
2
votes
1answer
1k views

How to calculate zonal statistics from multi-band raster with no attribute table

I have a raster image (.tif) that is multi bands (35 band), floating point data type that does not have attribute table, and a grid shapefile of 107 polygon created by the fishnet function in ArcGIS. ...
1
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1answer
374 views

Statistics on [FID] from table window

Try to do this and you'll get an error message. However you can easily get statistics on [FID] using Summary Statistics tool. Somebody has a good explanation of this? Also note that from within the ...
6
votes
1answer
3k views

Calculating Percentiles in ArcMap?

I have a large polygon dataset (26,000) records with numerous attributes columns. I wish to calculate the percentile rank of each attribute. Say I have population_density in an attribute, is there a ...
2
votes
2answers
144 views

Is it valid to adjust quantile buckets to “nice” numbers for better readability?

I'm making a map about terrorist attacks and fatalities in CartoDB. For data clustering I'm using quantiles. The calculated buckets are 16, 32, 50, 97, 700. Is it okay to adjust the quantiles to make ...
0
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2answers
2k views

Using Add Field, Calculate Field within ModelBuilder? [closed]

I have two questions regarding ModelBuilder. I have a point layer with Crop Yield values. I need to Add Field called "Count", then do a Calculate Field, Count = 1. The problem that I'm running into ...
1
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0answers
363 views

Road traffic database sample?

I would like to do some experiments on a traffic forecasting neural network and I need some real traffic data to run the network. My question is where can I download some real traffic statistics data ...
1
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1answer
656 views

Does calculating statistics in ERDAS change raster values?

I've been under the impression that calculating or recalculating statistics in ERDAS doesn't actually modify an image, but I notice when I do this that when I look at the image file in windows ...
-1
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1answer
1k views

Calculating average NDVI

I would like to calculate average NDVI values. I have 3 values of NDVI: high:243 low:0 high:243 low:0 high:238 low:0 How can I use a a raster calculator to calculate the average valvue
1
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0answers
37 views

Metrics of change between vector datasets

I have an old and a new set of parcel data which I'm looking to compare. I'm looking to compare changes in individual parcel geometries, so boundary/corner adjustment. Currently each parcel we have ...
6
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0answers
559 views

Zonal Histogram Output Problems - No values associated with the habitat type [closed]

I have a outline of some islands (shapefile or raster) and GAP landcover data (raster). I am trying to use Zonal Histogram to create a file with a histogram of the habitat types in each island. Each ...
4
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0answers
159 views

Web mapping API popularity

Are there any online statistics for the popularity/usage of web mapping APIs? A diagram would be sufficient, if it can be published in a paper. I have only found one source: https://trends.builtwith....
3
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1answer
160 views

How to make zonal statistics model more efficient?

I've made this model, to assess some 500-600 rasters for one area, and spit out one huge table. So far, when testing it with 20-30 rasters as inputs it works, but now that I put in the full amount its ...
4
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1answer
3k views

Scatterplot between two rasters in R?

I am very new in programming and I want to ask how can I make a scatterplot of two rasters in R and also get their correlation?
4
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1answer
46 views

raster statistics by line shape (vector)

I have a georeferenced area where I created 7 raster maps (classified with suitability values from 1 to 5) as I have 7 factors to check e.g. natural reserves, floods, slopes etc. From there I did a ...
4
votes
1answer
827 views

How to get counts from a table to produce a heatmap?

I am trying to create a heat map of doctors per zip code based on zip code. I have a table with the doctors and their zip codes, some of them repeating because there is more than one doctor per zip ...
2
votes
3answers
73 views

Raster statistics

In ArcMap, I have a raster layer representing site locations. I derived elevations values for the sites from a DEM. Now want stats on distribution of elevation values at those sites. How can I do this?...
0
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3answers
2k views

Capabilities of the Analytical Hierarchy Process (AHP) in conjunction with the weighted overlay tool

I am making a prospective map of fossil deposits using the "Weighted Overlay" ArcGIS tool. Input factor rasters are mostly topographic in nature (elevation, roughness, TPI, etc). Initially, I had ...
2
votes
1answer
28 views

Two maps, one with classes and one with no classes. get the sum of one map into the classes of the other

I have two maps. One map has some classes and the other one is a raster with no classes. To illustrate, the map with the classes: 0-1, 1-2 and 3-4! The other map is a raster with values from 0-1000. ...
1
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0answers
95 views

Plotting N-S and E-W Profile of Land Surface Temperature (LST) Across Land Use types in ArcGIS for Desktop?

I am working on my final year thesis and I need to plot the seasonal North-South and East-West profile of land surface temperature (LST) across various land use types. I have been able to extract ...
1
vote
1answer
93 views

Why am I getting small float numbers when aggregating points containing large integer values in QGIS?

I have a layer of points containing the centroids of European NUTS regions at NUTS 3, with population data in the atttribute table. I want to aggregate this population data to NUTS level 1, which is ...