ValueError: The number of classes has to be greater than one (python)

Question

When passing x,y in fit, I am getting the following error:

Traceback (most recent call last):

File "C:/Classify/classifier.py", line 95, in

train_avg, test_avg, cms = train_model(X, y, "ceps", plot=True)
File "C:/Classify/classifier.py", line 47, in train_model

clf.fit(X_train, y_train) File "C:\Python27\lib\site-packages\sklearn\svm\base.py", line 676, in fit raise ValueError("The number of classes has to be greater than" ValueError: The number of classes has to be greater than one.

Below is my code:

def train_model(X, Y, name, plot=False):
"""
    train_model(vector, vector, name[, plot=False])

    Trains and saves model to disk.
"""
labels = np.unique(Y)

cv = ShuffleSplit(n=len(X), n_iter=1, test_size=0.3, indices=True, random_state=0)

train_errors = []
test_errors = []

scores = []
pr_scores = defaultdict(list)
precisions, recalls, thresholds = defaultdict(list), defaultdict(list), defaultdict(list)

roc_scores = defaultdict(list)
tprs = defaultdict(list)
fprs = defaultdict(list)

clfs = []  # for the median

cms = []

for train, test in cv:
    X_train, y_train = X[train], Y[train]
    X_test, y_test = X[test], Y[test]

    clf = LogisticRegression()
    clf.fit(X_train, y_train)
    clfs.append(clf)

Calycine

scikit learn version 0.15.2 – Calycine

Answer 1

You probably have only one unique class label in the training set present. As the error messages noted, you need to have at least two unique classes in the dataset. E.g., you can run np.unique(y) to see what the unique class labels in your dataset are.

Stuyvesant

Just see you already have labels = np.unique(Y) in your code example. Just at a print, e.g., labels = np.unique(Y); print(labels) – Stuyvesant

it is printing : File "C:/Users/vshah/PycharmProjects/Classify/classifier.py", line 101, in <module> Starting classification train_avg, test_avg, cms = train_model(X, y, "ceps", plot=True) File "C:/Users/vshah/PycharmProjects/Classify/classifier.py", line 54, in train_model Classification running ... clf.fit(X_train, y_train) File "C:\Python27\lib\site-packages\sklearn\svm\base.py", line 665, in fit [] raise ValueError("The number of classes has to be greater than one" – Calycine

What you pasted above is not the print result but the error message that you posted earlier. You need to print it in a line before you encounter the error otherwise print(labels) will not get executed and you wouldn't now what the variable labels contains. – Stuyvesant

Answer 2

Exactly. your last column (label) has only one type (Classification). you should have at least two. For example; if your label is to decide either you have to offload or not, the label column should have offload and not-offload or (0 or 1).

Crampon

Answer 3

in my case, it gets label with wrong code, so list labels is like below

so there is one label in list labels

Subdiaconate