Questions tagged [confusion-matrix]

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

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GEE: How can I create error matrices from a large list of feature collections?

I have a list of feature collections, from which I want to produce error matrices. If I select one FC and create an error matrix I have no issue. If I use map to create 3 or 4, it usually works. If I ...
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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 ...
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Validation after mask on Google Earth Engine

In my code, I've used NDVI for detecting water; After creating a mask based on NDVI values, I want to make some validation analysis on my results; I need something like Error Matrix used in ...
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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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Land classification confusion matrix pixel total and toList() pixel total not matching

Using Landsat imagery and a CART classifier I have successfully carried out land classification and computed a confusion matrix for one full Landsat image, please see: https://code.earthengine.google....
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Accuracy assessment (confusion matrix) of image classification from Landsat imagery in SAGA GIS

I have classified Landsat images in two different classes, namely pervious and impervious, in SAGA GIS, using training sample in polygon shapes. This training sample has only one column of attribute ...
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Cannot get error matrix in Google Earth Engine

I'm trying to get the accuracy of my classification on sentinel-2. I use the code below: var bands = ['B2', 'B3', 'B4', 'B5', 'B6', 'B7','B8','B8A','B11','B12']; //Split sample data for training and ...
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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 ...
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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 ...
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93 views

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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247 views

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 ...
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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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439 views

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 ...
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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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695 views

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 ...
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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 ...
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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 ...
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247 views

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 ...
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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 ...
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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 ...
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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 ...
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1k views

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 ...
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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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3k views

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 ...