J48 is an open source Java implementation of the C4.5 algorithm in the Weka data mining tool.
Questions tagged [j48]
68 questions
1
vote
1 answer
Imbalance between errors in data summary and tree visualization in Weka
I tried to run a simple classification on the iris.arff dataset in Weka, using the J48 algorithm. I used cross-validation with 10 folds and - if I'm not wrong - all the default settings for J48.
The result is a 96% accuracy with 6 incorrectly…
M-elman
- 313
- 5
- 16
1
vote
0 answers
Student Performance using Decision Tree in Weka
I'm new at using weka. I want to use j48 for my project on Student Performance. I do not know how to edit the rules though. For example I have 8 subjects and need to get the average after getting the average if the total grade < 60 : Needs…
Phila
- 11
- 2
1
vote
1 answer
How C4.5 algorithm handles data with same attributes but different results?
I'm trying to create a decision tree with C4.5 algorithm for a school project. The decision tree is for Haberman's Survival Data Set, attribute information is as follows.
Attribute Information:
1. Age of patient at time of operation (numerical)
2.…
razorx
- 115
- 1
- 5
1
vote
1 answer
Probabilities Classification - R
First of all, sorry about my english, I am brazilian and I am improving it yet.
I am using RWeka to create classification models (NaiveBayes, JRip, J48, SVM) and I need the probabilities of each instance.
For SVM (package "e1041") I simply…
Bruna Zamith
- 55
- 1
- 7
1
vote
0 answers
The className is not appear when classifying instances using weka in java , why?
I try to do text classifying using weka library in my java program, but i have a bit problem
This my training data, there are 5 data, and two classes:
@relation hamspam
@attribute text string
@attribute class {ham,spam}
@data
'good',ham
'very…
Muhammad Haryadi Futra
- 253
- 1
- 5
- 11
1
vote
1 answer
How do I test a single Instance in Weka using a model that I have built?
I am trying to test a single instance using weka API in Java. My aim is to predict the class value of the single instance in the test.arff file.
My java code looks like this,
import weka.core.Instances;
import weka.classifiers.Evaluation;
import…
Shoeb Ahmed
- 25
- 4
1
vote
2 answers
How do I calculate the Confusion Matrix?
This is the WEKA output that i was able to generate. Unfortunatly, I do not know how to calculate the confusion matrix. Could someone help me calculate it?
=== Classifier model (full training set) ===
J48 pruned tree
-----------------
plas <=…
Adam Zeidan
- 21
- 6
1
vote
1 answer
weka.core.UnsupportedAttributeTypeException: weka.classifiers.trees.j48.C45PruneableClassifierTree: Cannot handle string attributes
I have the following code :
#load required library
library(data.tree)
library(entropy)
library(RWeka)
library(partykit)
library(FSelector)
library(e1071)
library(caret)
library(RWekajars)
#Load dataset
rest_contries <-…
H Dindi
- 1,484
- 6
- 39
- 68
1
vote
0 answers
J48 running in parallel
library(foreach)
library(doParallel)
data (iris)
### 18 sub datasets
N<-18
iris_dataset<-list()
for (i in 1:N) {iris_dataset[[i]]<-iris[sample(1:10, 1):sample(75:150, 1),]}
j48_c.models <-list()
cl<-makeCluster(8)
…
Avi
- 2,247
- 4
- 30
- 52
1
vote
1 answer
Weka improve model TP Rate
j48 weka
Hi,
I have problem with my model in weka (j48 cross-validation) that many instances are classified wrong when it comes to the second class. Is there any way to improve it or rather not? I'm not an expert in weka. Thank you in advance. My…
Sabina
- 25
- 1
- 1
- 6
1
vote
1 answer
RWeka J48 Classification issue in R and MovieLense data sets
I wanna classify Movielense users table demographic data but the result of J48 is weird, I classify my data with C5.0 and every thing was fine But I must work on this algorithm (j48)
structure of my data is like below
$ user_id : int 1 2 3 4 5 6…
Amir Fahmideh
- 255
- 2
- 11
1
vote
0 answers
R Weka J48 with snowfall for parallel execution
So I tried using the snowfall package for parallel execution in R, using all my cpu cores. This is the code I used for testing:
library(snow)
library(snowfall)
sfInit(parallel = TRUE, cpus = 16, type = "SOCK")
data <- array(1:1000000,…
Fermin
- 473
- 1
- 7
- 19
1
vote
1 answer
J48 Output decision tree node using WEKA
I am trying to learn about WEKA J48 decision tree from the cardiology-weka.arff .
I have run the output as below,
Test mode:10-fold cross-validation
=== Classifier model (full training set) ===
J48 pruned tree
------------------
thal = Rev
| …
user3292755
- 383
- 2
- 9
- 25
1
vote
1 answer
WEKA: get the class from classifyInstance,why it's wrong
I train and create a J48 model use WEKA Java Api.
Then, I use classifyInstance() to classify my instance.
but the result is wrong.
my code id following:
Instances train = reader.getDataSet();
Instances test = reader_test.getDataSet();
…
zhenshun chen
- 11
- 2
1
vote
2 answers
Weka throws comandline error when trying to use AdaBostM1 weka classifier with a J48 decisiontree classifier configured for pruning
I'm trying to run the following weka AdaBoostM1 classifier to boost a J48 tree that is configured for pruning below:
java -classpath ./bin/weka.jar weka.classifiers.meta.AdaBoostM1 -P 100 -S 1 -I 10 -W weka.classifiers.trees.J48 -- -C 0.25 -M 2 \
…
user3855422
- 219
- 1
- 7