Keras多标签分类“to\u categorical”错误

接收

索引器:索引3超出大小为3的轴1的界限

当尝试使用Keras to\u categorical对输出向量创建一个热编码时。 Y.shape = (178,1) . 请帮助(:

import keras
from keras.models import Sequential
from keras.layers import Dense
import numpy as np

# number of wine classes
classifications = 3

# load dataset
dataset = np.loadtxt('wine.csv', delimiter=",")
X = dataset[:,1:14]
Y = dataset[:,0:1]

# convert output values to one-hot
Y = keras.utils.to_categorical(Y, classifications)

# creating model
model = Sequential()
model.add(Dense(10, input_dim=13, activation='relu'))
model.add(Dense(15, activation='relu'))
model.add(Dense(20, activation='relu'))
model.add(Dense(classifications, activation='softmax'))

# compile and fit model
model.compile(loss="categorical_crossentropy", optimizer="adam", 
metrics=['accuracy'])

model.fit(X, Y, batch_size=10, epochs=10)