title: expected input to have 4 dimensions, but got array with shape
body: <p>I have this error </p>
  
  <blockquote>
    <p>Error when checking input: expected input_13 to have 4 dimensions, but got array with shape (7, 100, 100)</p>
  </blockquote>
  
  <p>For the following code how should I reshape array to fit with 4-dimensions, I searched for it but didn't understand the previous solutions. Please ask if not clear its very common issue in convolution neural network.</p>
  
  <pre><code>inputs=Input(shape=(100,100,1))
  
  x=Conv2D(16,(3,3), padding='same')(inputs)
  x=Activation('relu')(x)
  x=Conv2D(8,(3,3))(x)
  x=Activation('relu')(x)
  x=MaxPooling2D(pool_size=(2,2))(x)
  x=Dropout(0.2)(x)
  x=Dense(num_classes)(x)
  x=Activation('softmax')(x)
  output=Activation('softmax')(x)
  model=Model([inputs], output)
  </code></pre>