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Questions tagged [confusion-matrix]

A confusion matrix contains information about actual and predicted classifications done by a classification system.

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Accuracy of Confusion Matrix in Google Earth Engine

I want to check the classification accuracy using the confusion matrix in GEE, but I run into some problems. I generate some random points of known classification types and want to use them to check ...
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Extracting confusion matrix values in GEE

I am training a random forest model in Google Earth Engine, and I want to output the confusion matrices so I know which classes are being confused for which. By default, the confusion matrix is ...
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Confusion matrix in QGIS two vectors

I have two vector layers in QGIS. One is points from field-collected data, and the other is a polygonized raster that has been restricted to the raster values that most reflected the field data. ...
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Confusion matrix from two shapefile fields in QGIS

I have a shapefile with two columns one with joinreal and predicted values. I would like to calculate the confusion matrix between these two columns. I tried something in PyQGIS, but it does not work #...
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Creating sample points that cover all values of underlaying raster using R

I need to create sample points to extract the values of a predicted raster. The values correspond to the predicted classes and are NOT occurring in the same number. In order to be able to create a ...
talocodat's user avatar
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Legend for confusion matrix in R

I have created a confusion matrix plot in R however I would like to get the legend that shows the values for the colours. How would I do this? So far I have the following: z = c(135,9,0,7,0,0,55,3, ...
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Confusion matrix plot in r

I have a computed confusion matrix from google earth engine that I would like to use in r to derive a plot. how do I manually enter the confusion matrix and plot in R?. This is the confusion matrix: 1:...
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In Google Earth Engine (GEE) what is the difference between ConfusionMatrix() and errorMatrix()?

In the process of evaluating the classification of a satellite image, it is verified that the GEE has two available commands: ConfusionMatrix() and errorMatrix(). In some literature I see that both ...
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Fatal error using orfeo toolbox (otb 8.0.0) algorithm Computeconfusionmatrix in QGIS 3.22

I tried to compute a confusion matrix of a raster classification with otb's Computeconfusionmatrix using vector data (polygons) as reference input. When I run the same algorithm in mapla (otb ...
Mirje's user avatar
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What's the use of ImageCollection.errorMatrix() in Google Earth Engine?

In the docs there are two versions of the errorMatrix function: ee.FeatureCollection.errorMatrix and ee.ImageCollection.errorMatrix I've been sampling points from my classified images to create error ...
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Accuracy of threshold images

I am studying on identifying flood zones using Google Earth Engine. I calculated the NDWI index for the Sentinel 2 image. Then I set a threshold according to the OTSU thresholding method. I classified ...
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Creating formatted chart for Confusion Matrix using Google Earth Engine

I was curious how to create a formatted Confusion Matrix: (https://developers.google.com/earth-engine/apidocs/ee-confusionmatrix) I've completed my Supervised Classification, and I've created a ...
Paulito.Bandito's user avatar
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Accuracy assessment in GEE with an external data source

I'm new on GEE and I'm trying to perform an accuracy assessment of a supervised classification from S1 of a flood area, by the use of a confusion matrix. Once the model is created, in order to ...
Riccardo Ferri's user avatar
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Confusion Matrix in ArcGIS Pro not for accuracy but comparing two raster

I am wondering how to calculate or process confusion matrix on ArcGIS or other software for two raster data? I have tried to do it on ArcGIS by create accuracy point (~700 random point) to get the ...
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How to redesign confusion matrices from Ecognition with python and seaborn?

I am using eCognition manual classification as a baseline for performance comparison with other 3D classification methods. For each method, I am creating confusion matrices in python with sklearn and ...
JesEcog's user avatar
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Confusion matrices for two lists of raster objects

I have two lists of raster objects. One contains validation plots and the other contains results from a random forest binary classification of those plots. I would like to loop through both lists ...
RandomForester's user avatar
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How to exclude/eliminate invalid areas (such as NoData, cloud, water, etc) from raster so that it does not effect the accuracy assessment?

I have two classified raster (snow cover % 10-100) one is prepared from coarse resolution and another is from finer resolution. I am doing accuracy assessment and matrix calculation of snow cover %. ...
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When creating a confusion matrix, can you have more ground-truth points than the recommended 10-times the number of classes you have?

Using ArcGIS Pro, I classified a field of grain sorghum (supervises, pixel-based support vector machine) using 5 classes: Soil, Shadows, Leaves, Heads, and Ground targets (this was a UAS study). The ...
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Get a Confusion matrix in QGIS from two vectors

How and with what QGIS tools can I get a confusion matrix from a vector polygon layer as a verifiable classification and a vector point sample layer as a reference classification? That is, if the ...
Michael Larshin's user avatar
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Splitting up a region into training data and validation data for Landsat7 classification

I am building a classifier for Landsat7 by using MODIS land cover classification. My goal is to split up my region of interest into 80% being training data and 20% being validation data (with a ...
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Change size to the squares of the confusion matrix [closed]

I have a problem with size in the 'plot_confusion_matrix', the squares of the confusion matrix appear cut off. I would like to solve this problem. svc = SVC(kernel='linear',C=1,probability=True) svc....
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Confusion matrix from supervised learning

I am performing a supervised classification in GEE and want to verify how well my classifier has got trained. For this, I found a method confusionMatrix() and my respective program is var training = ...
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Generating confusion matrix using classified image with geotiff format?

I am working on yielding a confusion matrix with importing an image which is a geotiff format. After classified by a python program, The image has two values (two classifications). However, when I ...
Yuhao Wu's user avatar
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Confusion Matrix R

I'm having some problems to understand the result of my confusion matrix. Here is my case: I've run a classification (random forest) on a satellite image. To do so, I created 50 random points for ...
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Ground truthing with Google Earth

I need to obtain ground truth data of Google Earth for a certain region for the purpose of constructing confusion matrix. The data should correspond to Landcover classes. My main aim is to construct ...
Dark_Knight's user avatar
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Classification validation: Trouble with the Confusion Matrix

I'm supposed to validate my supervised classification with a Confusion Matrix, but I'm having a hard time getting what I should use as a comparison. At first, I used the same ROIs I created for ...
Eric Lino's user avatar
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Confusion matrix in ArcGIS 10.3

How can I get a confusion matrix using specific columns in two different rasters in ArcGIS ? I have one raster of risk classes 1,2,3,4 and another raster of land cover A, B, C,D. I am looking for a ...
user65127's user avatar
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Supervised Random Forest in R

I did an image classification using random forest algorithm in R. I got the result but I do not understand what does the confusion matrix shows ? I mean what does the rows and column show? These are ...
Maryam's user avatar
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Random Forest out of the bag and confusion matrix

I have implemented Random Forest classifier to classify remote sensing data in R. The original code comes from here: How to perform Random Forest land classification? Everything works fine, but what ...
Irij's user avatar
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How to interpret accuracy assessment results for classified data?

eCognition has the ability to perform an accuracy assessment for classified data by using an error matrix based on a TTA mask. The image shows the results of the accuracy assessment. Is there a ...
hatuta's user avatar
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R: creating an error matrix from two rasters

I have two land use rasters (6 classes each) and I'd like to create an error matrix (errors of omission and commission) from them both. The premise is that I have a very fine 'base' raster and have ...
Sam's user avatar
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Remote sensing accuracy assessment - McNemar`s Test

I would like to know how you determine the f12, f21 parameters for use in the McNemar`s test when for example I have two confusion matrices such as below: (where f12 = number of cells misclassified ...
Barry's user avatar
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Doing Accuracy Assessment using test data from shapefile in ENVI?

ENVI 5.2.1. From a .tiff image (4 bands) I created a Supervised Classification Maximum Likelihood .dat file. Now I want to perform an Accuracy Assessment using test data from a shapefile. I've tried ...
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Building confusion matrix for image classification using SAGA?

I did a supervised classification of a Landsat image subset using my training data polygons. I used SAGA GIS for that and everything worked out fine. Now I am stuck since I have no clue how to ...
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