Questions tagged [histogram]
a graphical representation of the distribution of observed data across the spectrum of classes of values.
102
questions
3
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Removing space between Histograms in QGIS
I would like to remove the space between the bars in the histograms but I cannot find a way to do so.
See the image below for reference.
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1
answer
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Does QGIS and GDAL result in a loss of clarity when converting a 16-bit image to 8-bit?
I am converting a 16-bit image to an 8-bit for an ML dataset.
The conversion script considers the min and max values of each band instead of a linear scale from 0-65535 to 0-255. However, the 8-bit ...
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1
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34
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Browser hangs while parsing georaster in geoblaze
I've been trying to create a histogram using geoblaze with a COG from s3.
The georaster is as follows: (generated with geoblaze.parse(url))
{
_data: '==hidden==',
projection: 32618,
height: ...
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0
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0
answers
24
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Adjusting raster histogram frequency axis
I am trying to create multiple raster histograms for comparison in QGIS. Therefore standardised axis are desirable. All the rasters contain the same number of pixels.
Adjusting histogram X-axis is ...
1
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0
answers
53
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QGIS Data Plotly widgets not installing correctly [closed]
I'm using QGIS 3.28.6 Firenze and installed the most recent version of Data Plotly. I'm trying to create a histogram with statistics of some data, and all the Data Plotly widgets don't show up when I ...
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0
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0
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49
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Global surface water/ How to compare area of latest image to older images and generate histogram
Based on the Global surface water script, I would like to compare the water decreasing per year and plot a histogram for the area lost per year. I know that there is a dataset that goes by monthly ...
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0
answers
69
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QGIS Zonal Histogram failure on high resolution multispectral orthomosaics
I'm trying to run zonal histograms on high resolution multispectral orthos collected via drone. I'm trying do do vegetation assessments on crop, and when I run the QGIS zonal histogram function it ...
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100
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Can I use histogram matching to harmonize two sensors data? (SPOT and Planet)
I have to image collections of SPOT (airbus) and Planet.
The images are not overlapped (from different locations) and are not from the same dates. However they have RGB-NIR.
I would like to be able to ...
- 1,967
1
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1
answer
131
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Working and saving histogram of data
I'm new to R and struggling to create a histogram and add a mean line. I've tried both hist() and doing it through ggplot, but keep seeing errors.
I'm using the newest version of R studio on a windows ...
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1
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49
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Using different Raster field when is not "Field" parameter for "input value raster" with arcpy.sa.ZonalHistogram
I want to get the Histogram of a Raster using the "Value" field in the raster attribute table.
The "feature zone data" is a shapefile and the "Input Value Raster" a 32Bit ...
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Google Earth Engine scaling behavior of discrete vs continuous image data
I have a simple question related to how GEE determines continuous vs discrete data, specifically during scaling operations as described here.
I am unable to find a proper description of this, but my ...
2
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1
answer
430
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Create one histogram for S2 ImageCollection in Google Earth Engine
I'm trying to compute ONE histogram for an entire ImageCollection in Google Earth Engine (example code here: https://code.earthengine.google.com/b10f5136a79a6309e381ae11aa9b7431)
What I'm doing now to ...
- 23
2
votes
1
answer
60
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Match feature diagrams with temporal fuction in QGIS
I am trying to create a time-dependent visualisation using a heatmap-styled points layer and a points layer with values to show at specific locations. The heatmap one shows occurrences over the ...
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75
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QGIS histogram shows non-existent values
I work with Sentinel-2 images. I wanted to plot a histogram of a cloudmask, but it showed non-existent values.
I used the MSK_CLDPRB_20m.jp2 layer, which is a raster that shows the probability of ...
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GoogleEarthEngine: Calculate histogram for every image in ImageCollection using map function and reduceRegion
I want to calculate histograms for every image in an ImageCollection with reduce.histogram. It works with a single image but I have problems mapping the function over the ImageCollection. I think the ...
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Rasterio show_hist display issue
I'm trying to display the histogram for the bands but I keep getting the following object whenever I execute show_hist.
Here is the code I executed:
from rasterio.plot import show_hist
show_hist(...
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375
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Calculate coverage of class types in GEE
I want to define coverage of each land cover type in my study area in Turkey-Isparta.
I call ("COPERNICUS/CORINE/V20/100m/2018") dataset and restrict it for my region as below (I load ...
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How to create a histogram of areas of clustered S1 image in Google Earth Engine?
I am using S1 images and clustering in Google Earth engine to identify different land uses. I clustered using ee.Clusterer.wekaKMeans(5).train. Now I want to create a histogram that shows the area per ...
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2
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How to manually adjust QGIS raster histogram X-values?
Background:
At 3.20.2 I am unable to manually adjust the raster histogram minimum and maximum X-values, as shown in the screen shot below.
There are fill-in boxes (within the red graphic box) which ...
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1
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Zonal Histogram - Python
My main goal is to get the percentage of vegetation cover of gardens. The figure below shows the gardens (orange borders) with vegetation and non-vegetation.
I want for each garden the percentage of ...
user162640
2
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1
answer
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Extracting pixel values in sample polygons in Google Earth Engine
I am trying to generate histogram of pixel values for my sample polygons. I used the code suggested on Histogram Matching in Google Earth Engine. Its working but I am not able to control the bin size ...
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108
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How to make histogram of NIR band bimodal enough to differentiate water from land in GEE? [closed]
I am interested to map water bodies in a desert from swir band of sentinel 2.
How I can make a bimodal histogram in GEE?
I have one reference water body in scene.
Is it possible to do the same in ...
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answers
211
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Chart multiple regions on one histogram
I'm having trouble trying to chart multiple regions onto one histogram.
var urban1 = urban.first().geometry();
var pine_forest1 = pine_forest.first().geometry();
var regions = ee.FeatureCollection([
...
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votes
1
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174
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Histogram of ratio between different pixels in Google Earth Engine
I would like to generate a histogram of the ratio between pixels within a polygon called "MODISofstation". Thereby all the pixels within my polygon should be compared to the pixel where my ...
- 111
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0
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952
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Reverse legend histogram palette in tmap
I'm trying to plot the histogram values with the same order as the color palette of a raster legend, passing the parameter legend.col.reverse = TRUE reverses the legend but not the histogram, since I'...
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Python Matplotlib Combine legend from histogram and lines [closed]
I wrote a Python script that uses matplotlib twinx to combine a histogram and some line functions plot as can see in the figure. However I was not capable of combining both legends (nb of points and ...
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1
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Control histogram axis and legend with show_hist of rasterio
I have load raster (Sentinel 2) with Rasterio and I would like to create histogram of the pixels.
The problem is that I beleive the graph gives automatically the X label and also the legend labels.
...
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1
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125
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Zonal histogram processing and invalid geometries
In QGIS 3.4, when I try to get a zonal histogram it returns an error related to invalid geometries in the vetor layer.
I've fixed geometries and, despite the layer have seemingly only valid ...
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0
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172
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Google Earth Engine unequal histogram values
I am creating histograms in Earth Engine of pixel values of cloud masked EVI from different years using Landsat 8. For each of the layers I create, I use an identical geometry to clip the output, but ...
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1
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100
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Error in raster histogram in QGIS3.0 with PyQGIS
I am working on a plugin, one of its functions is to create the raster layer histogram.
I generate the histogram using the histogram method of QgsRasterInterface and graph it well, without problems in ...
- 1,254
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294
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Image equalization after tiling, using gdal_translate -scale
I want to generate a set of samples from a Sentinel-2 image by tiling it, using mainly gdal_translate. The tiling is ok, but its histogram seems to vary tile to tile. So, what I thought was to apply ...
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113
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uint16 to float
I have a WorldView-2 satellite image in uint16 and the (for example) RED band histogram is
ranging from 1 to 3458.
As you can see, most of the values are within ~(130-500) with very few values ...
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196
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How to plot pies or histograms around points (GeoPandas) containing different level values indicators?
This is my code (a simple sample of df). I'd like to have around each point on a map, an histogram or pie showing the mechanical bikes out of the total.
import pandas as pd
pd.DataFrame(
{'...
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1
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244
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Export ReduceRegion fixedHistogram toDrive
I'm trying to export a fixed histogram from reduceRegion as a .csv file. I'm sure im missing the obvious here, but can't find a reasonable example that does this straightforward. I can do it as a ...
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Trying to understand Otsu method code in GEE
I hope this question is OK, I know it's not usual kind of questions that are being posted here.
I am trying to apply Otsu method on image in GEE. For that I have used the code that can be found here :...
- 1,967
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1
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2k
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Rasterio histogram save as image
I have create some histogram using DEM as dataset and rasterio using show_hist to take histogram but I can't find some way to save this histogram as image.any idea?
import rasterio
from rasterio.plot ...
- 1,061
3
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1
answer
510
views
Zonal Histograms in RQGIS3
I would like to calculate zonal histograms (number of raster cells of each type contained in a polygon) using the RQGIS3 package in R. The problem is that I can't seem to find the algorithm name for ...
4
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1
answer
84
views
Setting Bin Count in QgsRasterHistogram
Following this question, I am trying to use QgsRasterHistogram to obtain a histogram of my raster image. However, I cannot figure out how to change bin count.
I looked at the docs here, and it would ...
- 113
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1
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128
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Google Earth Engine chart error: No features contain non-null values of “year” [closed]
I'm trying to plot a chart from a collection I have created. While the data from this collection maps fine, I can't seem to produce a chart for it. Here is the code:
var l5_coll = ee.ImageCollection('...
3
votes
1
answer
3k
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Trying to make a histogram with ui.Chart.image.histogram() in GEE
I'm trying to make a histogram with the difference of two NDVI images from different dates, but I'm having trouble with the ui.Chart.image.histogram() function when I try to perform with my large ...
0
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0
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252
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Calculate histogram from raster stored in GeoServer
I have a raster stored in GeoServer which I can show it with Openlayers in my web page:
raster = new TileLayer({
source: new TileWMS({
url: 'http://myip/geoserver/myworkspace/wms',
params: {...
- 343
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0
answers
405
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Histogram from multiple raster in one graph in QGIS?
I have more than 10 rasters which are actually MNDWI index images created from Landsat image. I want to visualize all rasters (tiff) files in one graph to understand the spectral distribution. Is ...
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votes
1
answer
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Counting number of points in each grid?
I would like to count the number of points in each cell. I have tried https://docs.scipy.org/doc/numpy/reference/generated/numpy.histogram2d.html but the out isn't appropriate. Does anybody know how I ...
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0
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627
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Histogram matching in Google Earth Engine?
Does anyone know if there is a more GEE-friendly way of achieving this? I'm experimenting with S1 SAR image histogram matching in GEE and was wondering if foremost the code can be improved. Read here ...
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0
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50
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Query of line direction histogram plugin
I was wondering if anyone could explain how this plugin works I have had a play around with it and I do like how it visualizes how vectors are orientated. However I ran one and opened the CSV file ...
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1
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Fixing Histogram selectionChanged from Carto Airship 1.04 to 2.00?
I have spent quite a bit of time playing around with this generous example provided by Jorge Sanz of Carto:
https://gist.github.com/jsanz/8025628d669f1d9d0647f658f5511774
One thing I've gotten stuck ...
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1
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1k
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Making raster histogram excluding zeros in R?
In R, can I make a histogram of all the non-zero values in my raster?
Some reproducible data below. I just want the histogram to be made with the zeros. Happy with a way to do that, or I guess to ...
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1
answer
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Unrecognized argument type to convert to a FeatureCollection:
I am unable to chart a histogram for my region for each image in an image collection.
// Create clipping function
var clipper = function(image){
return image.clip(geometry);
};
var modis = ee....
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1
answer
1k
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How to reduce a custom bin histogram for a region in Google Earth Engine?
I'd like to reduce all the conties' data histogram with a custom bin, but what I got is a auto bin histogram, it seems ee.Reducer.fixedHistogram() can help, but I don't know how to pass the parameters(...
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2
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Values on top of each bar of a histogram in QGIS
Is it possible to show the values on top of each bar of a histogram created with QGIS? (I am using QGIS 2.18)
I know this post [Is it possible to label bar charts? addressed a similar question years ...
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