Questions tagged [statistics]

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

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0answers
231 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
308 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 ...
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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 ...
3
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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. ...
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1answer
413 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
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1answer
4k 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 ...
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2answers
155 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 ...
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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 ...
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0answers
388 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
697 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 ...
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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
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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 ...
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0answers
577 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
162 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
177 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
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1answer
903 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
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3answers
75 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?...
2
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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. ...
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0answers
99 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 ...
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1answer
103 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 ...
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1answer
955 views

arcpy SearchCursor return a OBJECTID value not as an integer

I use summary statistics GP tool to extract the max OBJECTID from a feature layer. After that I use arcpy SerachCursor to get the OBJECTID value from the statistics, but the result returned is not an ...
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0answers
23 views

Calculation of RMS between two grids [duplicate]

I want to calculate the RMSE of two grids based on their z-value: a calculated and a reference grid. I do have the statistics: Cells, Range, Min, Max, Sum, Mean, Variance, St.dev. How could I solve ...
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0answers
224 views

Statistically comparing positions from two track datasets? [closed]

I have two datasets with positions that I need to compare. One would be the "observed" positions (someone took the GPS positions manually) and the other one was calculated using a software. To use ...
6
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1answer
780 views

Why covariance values are different in R and ArcGIS?

I've calculated covariance between 7 rasters using R and ArcGIS. It gives me different results. Each times covariance values from R are approximately 1.874 times higher than ArcGIS values. R - ...
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1answer
628 views

Intersect shapefile with raster, then determine proportion of each raster value?

Using the arcpy module in Python, I want to find the proportion of each pixel value within the boundary of an overlaying polygon. (The polygon is in a shapefile.) For example, there are 10 possible ...
7
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3answers
1k views

Is it possible to calculate statistics across multiple fields in arcpy?

The summary statistics command can be used in arcpy to calculate statistics - this tool runs against a single field, eg: SUM—Adds the total value for the specified field. Is there an out-of-the-...
7
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2answers
15k views

How are kappa and overall accuracy related with respect to thematic raster data?

I recently calculated kappa (using confusionMatrix{caret} in R) between a thematic raster dataset at 1m spatial resolution and another at 30m spatial resolution. I was interested in quantifying the ...
7
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1answer
461 views

Graphically depict statistical difference between thematic rasters

The graph shows a regression between two raster datasets with classified tree canopy cover: class 1 = 0-10%, class 2 = 10 - 20% ...class 6 = >60% (Figure 1, Figure 2). The spatial resolution for ...
4
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2answers
1k views

Using MAX in SQL Expression of ArcMap ModelBuilder

I am trying to use a SQL expression in order to select values that are >= 25% of its max value in that column. For instance, VALUE >= MAX(VALUE)*0.25, and those will ultimately be the selected ...
4
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1answer
496 views

Extracting LiDAR metrics with TerraScan?

I want to extract from a las file statistics such as height percentiles (percentile 95, for example) among others. I can do it with Fusion (using Cloudmetrics and Gridmetrics tools), but I would like ...
2
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3answers
975 views

How I can sum 360 raster files in a folder with the Arcgis raster calculator?

In a folder I have 360 precipitation raster files and I want to sum them all to the raster calculator
3
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1answer
157 views

Statistical Analysis of Shapefile Proximity within Raster Image using ArcMap?

I have a raster image that has been reclassified into 15 equally incremented values/levels. This raster represents "sinkhole risk" in a certain county. So level 1 is the lowest risk region and level ...
2
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1answer
1k views

Summarizing Table on 2 fields

I have a table of Census Blocks linked to ZIP4 values. I'm trying to create another table getting the unique ZIP4 values associated with each Census Block. I've tried using the Frequency, and Summary ...
0
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1answer
150 views

How to implement a Gaussian function in field calculator?

Are there any build-in functions like Gaussian or Epanechnikov functions in field calculator? Or I have to write that by myself?
0
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1answer
72 views

Calculating GRID Statstics

I have a GRID raster dataset with no calculated statistics. I have tried building pyramids and calculating statistics with no luck. What am I missing? EDIT: For those who don't understand: 1. ...
0
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2answers
1k views

Lengths of lines within individual but overlapping buffers?

I have a set of points for which I have created a 12 mile buffer. Eventually, I would like to know how many kilometers of road exist within each buffer zone individually? The problem I see going ...
3
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1answer
3k views

Deriving Z-score values for given field using ArcGIS for Desktop?

I have a shapefile with an attribute field with a range of numerical values. How do I derive z-score values for this field using ArcGIS for Desktop?
1
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1answer
2k views

Counting all features in all layers of ArcGIS map to get grand total?

I have 20-50 polygon layers in an mxd and I want to find out the aggregated amount of all features (global count). The shapefiles which are the source of those layers are stored in different folders. ...
0
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3answers
502 views

Changing Values Greater than Standard Deviation of Mean to Zero using ArcMap?

I have a feature class with greater than 1000 features and I would like to change all values greater than 2 Standard Deviations to a Zero. Seems like I could possibly use Field Calculator for ...
4
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2answers
1k views

Methods for hot spot or cluster analysis for multiple measurements at the same geographic unit?

I would like to find geographic clusters of zip codes where each zip code has a measurement of a person's age (integer), sex (categorical/binary), and if they recovered from a certain medical ...
0
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1answer
813 views

Get the different values assigned to a zip code

I have a map to which I added a zip code layer and another layer which contains values assigned to every square kilometer within each zip code. I'm trying to find out how many different values there ...
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2answers
249 views

Determining Min - Max within zip code (statistics by area)?

I'm new to ArcGIS Desktop. I have created a layer representing zip codes and overlayed it with a layer containing some data points. I want to find the min and max value of the data points in each zip ...
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0answers
2k views

Using pivot table output? [closed]

In an attempt to summarise landclasses, the columns of my pivot table output are a bit mixed up with the field info regarding the three input fields that I've selected. As shown in snapshot 3 the ...
0
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2answers
445 views

How to track ajax WMS requests in OpenLayers interface?

I'd like to track WMS requests on my openlayers web interface. How is it possible to log on my server or in Google Analytics every WMS requests (GetMap and GetFeatureInfo would be enough)? Then I'd ...
1
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1answer
858 views

Running regression in each sample separately? [closed]

I'd like to smooth an NDVI image by regression analysis; response of time series NDVI image to Julian date to represent the seasonal changes in NDVI as a function of Julian day. The time series NDVI ...
1
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1answer
197 views

How to analyse point data as covariate for areal data

I have two data sets: a) a set of polygons with areal data variables. b) point measures of various co-variates of interest (note I do not necessarily have a point for each polygon) How do I ...
3
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1answer
547 views

Overview of statistical maps/charts types

I know of a few ways to visualize statistical information on a map, like choropleth maps, prism maps or simply displaying little bar-charts or pie-charts near locations on a map. But there must be a ...
1
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3answers
467 views

How to add a pie chart based on all (or some) features in a layer?

I have a vector layer in a QGIS project which has about 60 items with various attributes, including a check for if an item is complete. I am trying to get a pie chart showing the percentage of the ...

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