混淆矩阵ValueError:发现输入变量的样本数不一致:[3,360]

问题描述

我正在尝试训练数据集,并在训练完数据集后输出混淆矩阵。

这是代码

import tensorflow as tf

from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Dense,Conv2D,Flatten,Dropout,MaxPooling2D
from tensorflow.keras.preprocessing.image import ImageDataGenerator 

from tensorflow import keras
from tensorflow.keras import layers
from tensorflow.keras import Input

from tensorflow.keras.layers import Dropout
from tensorflow.keras.layers import softmax
from tensorflow.keras.layers import GlobalAveragePooling2D
from tensorflow.keras.layers import Convolution2D

import os
import numpy as np
import matplotlib.pyplot as plt

import scipy as sp 
from scipy import signal
from scipy.signal import chirp
import numpy.fft
from numpy.fft import fft as rf
import random
import pandas as pd
import sklearn.model_selection as model_selection
import matplotlib.pyplot as plt
import tensorflow as tf

from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Dense,MaxPooling2D
from tensorflow.keras.preprocessing.image import ImageDataGenerator 

from tensorflow import keras
from tensorflow.keras import layers
from tensorflow.keras import Input

from tensorflow.keras.layers import Dropout
from tensorflow.keras.layers import softmax
from tensorflow.keras.layers import GlobalAveragePooling2D
from tensorflow.keras.layers import Convolution2D

import os
import numpy as np
import matplotlib.pyplot as plt

import scipy as sp 
from scipy import signal
from scipy.signal import chirp
import numpy.fft
from numpy.fft import fft as rf
import random
import pandas as pd
import sklearn.model_selection as model_selection
import matplotlib.pyplot as plt

from sklearn.datasets import make_blobs
from sklearn.naive_bayes import GaussianNB
from sklearn.metrics import brier_score_loss
from sklearn.calibration import CalibratedClassifierCV
from sklearn.model_selection import train_test_split

from sklearn.datasets import make_blobs
from sklearn.naive_bayes import GaussianNB
from sklearn.metrics import brier_score_loss
from sklearn.calibration import CalibratedClassifierCV
from sklearn.model_selection import train_test_split

from PIL import Image
import imageio as io 
import glob
from matplotlib import image

  
import h5py
from tensorflow.keras.models import Model
from tensorflow.keras.layers import Input,Activation,concatenate
from tensorflow.keras.layers import Flatten,Dropout
from tensorflow.keras.layers import Convolution2D,MaxPooling2D
from tensorflow.keras.layers import AveragePooling2D

from tensorflow.keras.layers import Input,Concatenate,\
     MaxPool2D,GlobalAvgPool2D,Activation

def squeezenet(input_shape,n_classes):
  
  def fire(x,fs,fe):
    s = Conv2D(fs,1,activation='relu')(x)
    e1 = Conv2D(fe,activation='relu')(s)
    e3 = Conv2D(fe,3,padding='same',activation='relu')(s)
    output = Concatenate()([e1,e3])
    return output
  
  
  input = Input(input_shape)
  
  x = Conv2D(96,7,strides=2,activation='relu')(input)
  x = MaxPool2D(3,padding='same')(x)
  
  x = fire(x,16,64)
  x = fire(x,32,128)
  x = MaxPool2D(3,128)
  x = fire(x,48,192)
  x = fire(x,64,256)
  x = fire(x,256)
  x = MaxPool2D(3,padding='same')(x)
    
  x = Dropout(0.6)(x)
    
  x = Conv2D(n_classes,1)(x)
  x = GlobalAvgPool2D()(x)
  x = Flatten()(x)
  
  output = Activation('softmax')(x)
  
  model = Model(input,output)
  return model

  import pathlib
import PIL

test_datagen = ImageDataGenerator(rescale=1./255)


data_dir = os.path.join(r"location/directory of the file","file")

data_dir = pathlib.Path(data_dir)

image_count = len(list(data_dir.glob('*/*.png')))
print(image_count)

rect = list(data_dir.glob('Rect/*'))
PIL.Image.open(str(rect[1]))


batch_size = 32
img_height = 227
img_width = 227

train_ds = tf.keras.preprocessing.image_dataset_from_directory(
  data_dir,validation_split=0.1,subset="training",seed=123,image_size=(img_height,img_width),batch_size=batch_size)

val_ds = tf.keras.preprocessing.image_dataset_from_directory(
  data_dir,subset="validation",batch_size=batch_size)

class_names = train_ds.class_names
print(range(len(class_names)))

AUTOTUNE = tf.data.experimental.AUTOTUNE

train_ds = train_ds.cache().shuffle(1000).prefetch(buffer_size=AUTOTUNE)
val_ds = val_ds.cache().prefetch(buffer_size=AUTOTUNE)

normalization_layer = layers.experimental.preprocessing.Rescaling(1./255)

normalized_ds = train_ds.map(lambda x,y: (normalization_layer(x),y))
image_batch,labels_batch = next(iter(normalized_ds))
first_image = image_batch[0]
# Notice the pixels values are Now in `[0,1]`.
print(np.min(first_image),np.max(first_image)) 

from keras.optimizers import SGD
from keras.callbacks import EarlyStopping,ModelCheckpoint
from keras.preprocessing.image import ImageDataGenerator


model = squeezenet((227,227,3),2)

sgd = SGD(lr=0.001,decay=0.0002,momentum=0.9,nesterov=True)
model.compile(
optimizer=sgd,loss='binary_crossentropy',metrics=['accuracy'])

print(model.summary())

acc = history.history['accuracy']
val_acc = history.history['val_accuracy']

loss=history.history['loss']
val_loss=history.history['val_loss']

epochs_range = epoch #range(epochs)

plt.figure(figsize=(8,8))
plt.subplot(1,2,1)
plt.plot(epochs_range,acc,label='Training Accuracy')
plt.plot(epochs_range,val_acc,label='Validation Accuracy')
plt.legend(loc='lower right')
acc = history.history['accuracy']
val_acc = history.history['val_accuracy']

loss=history.history['loss']
val_loss=history.history['val_loss']

epochs_range = epoch #range(epochs)

plt.figure(figsize=(8,label='Validation Accuracy')
plt.legend(loc='lower right')
plt.title('Training and Validation Accuracy')

plt.subplot(1,2)
plt.plot(epochs_range,loss,label='Training Loss')
plt.plot(epochs_range,val_loss,label='Validation Loss')
plt.legend(loc='upper right')
plt.title('Training and Validation Loss')
plt.show()
plt.title('Training and Validation Accuracy')

plt.subplot(1,label='Validation Loss')
plt.legend(loc='upper right')
plt.title('Training and Validation Loss')
plt.show()

#supply a imafe to classifer to get an image out 
#calculate the confusion matrix manualy 

from sklearn.metrics import classification_report,confusion_matrix


Y_pred = model.predict_generator(val_ds,720 // 32+1)
y_pred = np.argmax(Y_pred,axis=1)
print(y_pred.shape)
print('Confusion Matrix')
print(confusion_matrix(class_names,y_pred))
print('Classification Report')
target_names = ['Cats','Dogs','Horse']
print(classification_report(class_names,y_pred,target_names=target_names))

这是我遇到的错误

ValueError                                Traceback (most recent call last)
<ipython-input-9-5188ce05905a> in <module>
      9 print(y_pred.shape)
     10 print('Confusion Matrix')
---> 11 print(confusion_matrix(class_names,y_pred))
     12 print('Classification Report')
     13 target_names = ['Cats','Horse']

in confusion_matrix(y_true,labels,sample_weight)
    251 
    252     """
--> 253     y_type,y_true,y_pred = _check_targets(y_true,y_pred)
    254     if y_type not in ("binary","multiclass"):
    255         raise ValueError("%s is not supported" % y_type)

in _check_targets(y_true,y_pred)
     69     y_pred : array or indicator matrix
     70     """
---> 71     check_consistent_length(y_true,y_pred)
     72     type_true = type_of_target(y_true)
     73     type_pred = type_of_target(y_pred)

in check_consistent_length(*arrays)
    203     if len(uniques) > 1:
    204         raise ValueError("Found input variables with inconsistent numbers of"
--> 205                          " samples: %r" % [int(l) for l in lengths])
    206 
    207 

ValueError: Found input variables with inconsistent numbers of samples: [3,360]

解决方法

confusion_matrix方法中,您的参数应该为y_truey_pred,就像您可以找到的in the doc一样。

似乎您的第一个参数y_true(= class_names)的大小为3,第二个参数y_pred的大小为360。但是,自{{1} }是您分类的估计结果,而y_pred是分类的基本事实。

以下是与sklearn相关的示例,使用了3个类:y_true

[0,1,2]

编辑

from sklearn.metrics import confusion_matrix y_true = [2,2,1] y_pred = [0,2] confusion_matrix(y_true,y_pred) 的结构如何?

通常y_true包含与每个输入对应的每个标签。您似乎给分类器提供了360个输入,因此对于每个输入,您都应该有一个关联的标签,即y_true之一。包含输入的真实标签的完整向量为class_names