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

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2
votes
2answers
704 views

Iterate through multiple Raster files and compute statistics using Zonal Statistics

I have a large number of raster images. What I'd like to do is to compute statistics on different sections of these raster files using a polygon. I think everyone is suggesting Zonal statistics. ...
11
votes
5answers
3k views

Get Raster Values from a Polygon Overlay in Opensource GIS Solutions

I have two layers. A polygon-shape-layer with many tiles and a raster-layer containing CORINE 2006 land cover with many categories in a colourmap. I want to obtain for each polygon in the shapelayer a ...
7
votes
3answers
5k views

How to calculate raster statistics for polygons?

how can I calculate sums, averages etc of raster-points (multi-band) per polygon of a vector-layer. I was told that this is called "zonal statistics". I tried that with QGIS first. There is a way to ...
1
vote
2answers
102 views

Min - Max within a zip code (statistics by area)

I'm new to ArcGIS. 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 code. ...
7
votes
1answer
2k views

Are there QGIS tools that will allow users to get tabular statistics from their table?

Are there QGIS tools that will allow users to get tabular statistics from their table? I kind of expected I would be able to just open the table, select the field I was interested in, right-click on ...
6
votes
4answers
1k views

How to sum up pixel values in QGIS?

I need to know the value of the sum of all pixels in a raster. However, in the Statistics section of the Metadata tab in Properties, under Sum of All Cells it always indicates 0.00. I have tried with ...
7
votes
1answer
2k views

How to get GDAL to create statistics for GTiff in Python

I regularly create my own GeoTIFF rasters with GDAL in Python, e.g.: from osgeo import gdal from numpy import random data = random.uniform(0, 10, (300, 200)) driver = gdal.GetDriverByName('GTiff') ds ...
5
votes
2answers
151 views

Different models, different contours: are they comparable?

I will get contour lines of electromagnetic field strength around power lines. The contours will be calculated by different agencies using different models. We need to check whether the resulting ...
5
votes
2answers
2k views

Frequency, summarize tool options of ArcGIS for Desktop?

I'm looking for some general frequency, summarize tool. What I basically want is some tool like the summarize tool in ArcGIS (right click in the attribute table> summarize) that runs on all attributes ...
6
votes
1answer
1k views

ArcGIS median value from a layer

I've been hunting around ArcGIS 9.3 and having no success at finding a tool/function that can give me the median (not the mean/avg) tabular value of a spatial database. For example, if I have a data ...
4
votes
1answer
600 views

How to use/interpret/visualise a distance matrix with unknown coordinates?

How would you go about using a distance matrix where points have no coordinates, i.e. what useful statistics can be made and how to visualise it in some useful way?
3
votes
1answer
570 views

API for Real Time World Statistics

Does anyone know of an API (preferably free) that can provide real time world statistics such as Crude Birth Rate, Crude Death Rate, world/country population, or emails sent today as on the website ...
3
votes
1answer
2k views

How to detect duplicate attribute values in a table using ArcPy

In ArcMap, the right-click Summarize option very quickly creates a frequency listing of the chosen field: Note that the count field shows the count of duplicate values. How can I access this ...
6
votes
2answers
2k views

Is it possible to access ArcGIS's table operations “Summarize…” and “Statistics…” in python?

ArcGIS has a few nifty table tools, including Summarize and Statistics. Is there a way to access them through arcpy, or will I have to hack my own methods via math and lists?
5
votes
2answers
3k views

Calculate area of intersecting polygons in QGIS

I have two collections of shapefiles: 1 - postal codes, administrative and political areas 2 - various land use categories like parks & allotments, and points like trees I want to produce ...
0
votes
1answer
48 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 ...
0
votes
1answer
120 views

Do I need to run regression in each samples separately?

I'd like to do smooth 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 ...
0
votes
0answers
60 views

How to calculate sums for all fields in a table? [duplicate]

Possible Duplicate: are there any methods can choose all field and make the SUM for each fields or I must do it one by one? Are there any methods that can calculate the summary statistic ...