ch02_basics/Concept02_evaluating_ops.ipynb

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   "source": [
    "# Ch `02`: Concept `02`"
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    "## Evaluating ops"
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    "Import TensorFlow:"
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   "source": [
    "import tensorflow as tf"
   ]
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    "Start with a 1x2 matrix:"
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   "source": [
    "x = tf.constant([[1, 2]])"
   ]
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   "source": [
    "Let's negate it. Define the negation op to be run on the matrix:"
   ]
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    "neg_x = tf.negative(x)"
   ]
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    "It's nothing special if you print it out. In fact, it doesn't even perform the negation computation. Check out what happens when you simply print it:"
   ]
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      "Tensor(\"Neg_3:0\", shape=(1, 2), dtype=int32)\n"
     ]
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    "print(neg_x)"
   ]
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   "source": [
    "You need to summon a session so you can launch the negation op:"
   ]
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     "text": [
      "[[-1 -2]]\n"
     ]
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   "source": [
    "with tf.Session() as sess:\n",
    "    result = sess.run(neg_x)\n",
    "    print(result)"
   ]
  }
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