Questions tagged [frequency]
The frequency tag has no usage guidance.
26
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R raster stack mathematical conditioning operation
I am new to R and currently I am trying to create a drought frequency map using a stack of VHI rasters but, I still can't figure out a way. My attempt is as follows.
The stack of rasters contains data ...
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1
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294
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Create a frequency map from overlapping polygons (for large/complex polygons)
I have vector layers (polygons) of burned areas for a series of 33 years and i need to create a frequency map from the overlapping of this polygons (1 if there is no overlapping, 2 if there are two ...
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458
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Union of shapefiles to generate composite shapefile with overlap frequency count for each polygon
I'm new to QGIS, making the switch from ArcMap. I have 5 shapefiles of polygons representing 5 years of insect defoliation. I need to overlay the 5 years and create a new composite shapefile that is a ...
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27
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ArcMap frequency table of field values that are above a certain value in another field
I am using ArcMap 10.5. I have a table of species list length from visits to sites over a period of years. I have a column for site, giving the grid reference of each site, and a column giving the ...
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Calculate frequency based on a filtered field, and put the value in another field
I'm a python beginner.
I'm working on one feature class, i would like to group this feature based on group_ID field, and then for each one of this group i would like to calculate the number of rows ...
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169
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ArcMap get frequency of different values in text field
I am using ArcMap 10.5. I have a large dataset of species records and ultimately want to display a breakdown of the data by different taxon group, e.g. 'bird' 'mammal' 'plant' etc., using something ...
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167
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Frequency analysis of linestring using QGIS
I have a data-set that consists of linestrings across different timestamps. I want to identify the segments that occur the most frequently.
I am using R to import the data from JSON files, create ...
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474
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Calculating frequency in Field Calculator
I have a table with many instances of duplicate values.
My end goal is to have three columns:
"The Value": a file name. most are non-unique
"Duplicate Instance": "this is the 1st time this file name ...
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158
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Determine the most frequent value for an attribute based on another attribute [closed]
I need to determine the most frequent value of one attribute based on another.
For example:
Field 1 Field 2
Cat Tabby
Cat White
Cat White
Dog Brown
Dog ...
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227
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Pivoting Tables and using Frequency in ArcGIS Desktop?
I have a points layer of specimen samples. They have a field called "RESULT" which is a string field containing the results of a test, "Positive" and "Negative"(you can only see negative in the pic ...
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258
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Getting a frequency matrix of overlaying raster values
I have two raster datasets (a World Soil Map and Global Horizontal Irradiance), which I merged together in QGIS in order to get values of both channels for every pixel.
The Soil Map has 30 soil type ...
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55
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How to find frequency of a field based on another attribute?
I'm working in ArcMap. I have a list of people and the states that they live in. Small Example:
I want to know what is the most common name in each state.
I thought I would use the frequency tool ...
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2
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1k
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Equal Time Maps for Transit Network (Isochrones) on QGIS
I am on a committee looking to redesign transit service in Sacramento and need to be able to make equal-time maps or "isochrones," like the attached.
A prominent difference between transit isochrones ...
2
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230
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Counting frequency of specific value in selected columns of an attribute table of the feature class in ArcGIS 10.4 [closed]
I want to calculate the number of members in the houses (feature class which contain information of the members in the house interms of age,sex,occupation) based on the information entered in age ...
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What is GPS epoch?
What is a GPS epoch?
I encounter this often in technical discussions and it does not have a clear meaning to me. Lately it was used in Maximum frequency of camera event and it seems to mean the ...
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Reclassifying NDWI using Google Earth Engine?
I'm trying to reclassify a NDWI raster into 1 for values >0.4 and 0 for <0.4. I understand that its possible to use .remap in case of discrete values, but not sure how to reclassify NDWI raster ...
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Creating buffer based on occurrence frequency using ArcGIS Desktop?
I am using ArcMap 10.4.1.
I have several point shapefiles containing different occurrence data for two different species of flower (from multiple sources, hence the multiple shapefiles). I want to ...
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2
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544
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Zonal histogram completed but no output created
I am trying to obtain zonal histogram data for about 10 000 statistical sectors in Belgium.
So I have a shapefile containing these polygons.
I also have a value raster which has been reclassified : ...
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1
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496
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Large raster frequency table / counts
I try to calculate the frequency/count of pixel values of a raster in R using freq().
library(raster)
RastSmall <- raster(nrow=70, ncol=70)
RastBig <- raster(nrow=7000, ncol=7000)
set.seed(...
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Reassigning Raster values to new values in QGIS?
For example, if the Raster has integer values ranging from -1 to 3 and the value that I am only interested in is 3, I then want to assign values -1 to 2 to 0 and then have the 3 value set to the value ...
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Create frequency polygon from overlapping features in another polygon
Mac 10.9.5; QGIS 2.8.4-Wien; history and unioned data, in GDA94, zone 55 here.
I have a polygon of fire history with a number of overlapping features. I want to create a new polygon for fire ...
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How to extract all pixel values in a raster file [duplicate]
I have a image difference from ArcGIS, which i have performed a remap function on.
The layer is a temporary layer and does not have an attribute table, i need all the pixel values to do a frequency ...
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632
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ArcGIS frequency analysis tool
Will the ArcGIS frequency analysis tool work on a shapefile's attribute table or does it only work on a discrete/standalone table loaded in a mapping session?
Have loaded a geolocated address book ...
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Proper Use of QGIS tool: "Frequency analysis"
Trying to use the "Frequency analysis" tool in a script but getting errors.
The Online documentations for this tool:
processing.runalg('qgis:frequencyanalysis', input, fields, output)
My Script:
...
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352
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Batch frequency of point groups to single table in ArcGIS Desktop? [duplicate]
I'm new in the GIS world.
I have a bunch of points (around 40,000), which are split in categories (1 to 9) and have a field which specifies their membership to a polygon (~50) (e.g, 30, which would ...
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Recording frequency of names in the attribute table?
I have a question with ArcGIS 9.2. In an attribute table the column [name] includes the name of every place in this layer. Next to that (in columns [numbers]) there should be recorded how often a ...
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