Questions tagged [confusion-matrix]
A confusion matrix contains information about actual and predicted classifications done by a classification system.
20
questions
1
vote
1answer
42 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 %. ...
0
votes
0answers
26 views
Accuracy classification in Google Earth Engine
I'm trying to perform a supervised classification of a composite image from a Sentinel-2 time series. I'm using cart as classifier and a set of points as trainers. Once computed the classification I'm ...
1
vote
0answers
14 views
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 ...
1
vote
1answer
48 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 ...
3
votes
1answer
72 views
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 ...
0
votes
0answers
14 views
Adding random points inside shapefile using ArcGIS Pro for matrix check
I have a vector shapefile for each landcover class, with multiple features.
How can I add random points inside the shapefile using ArcGIS Pro for matrix check?
For example, for Built landcover ...
2
votes
0answers
175 views
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....
1
vote
0answers
81 views
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 = ...
0
votes
1answer
385 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 ...
3
votes
1answer
982 views
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 ...
0
votes
1answer
455 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 ...
0
votes
1answer
180 views
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 ...
4
votes
1answer
2k views
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 ...
1
vote
0answers
221 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 ...
3
votes
1answer
5k views
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 ...
-1
votes
1answer
1k views
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 ...
2
votes
2answers
681 views
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 ...
2
votes
1answer
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 ...
0
votes
1answer
2k views
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 ...
3
votes
1answer
2k 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 ...
