using Microsoft.VisualStudio.TestTools.UnitTesting;

using NumSharp;

using System.Linq;

using Tensorflow;

using static Tensorflow.Binding;

namespace TensorFlowNET.UnitTest

{

[TestClass]

public class GradientTest

{

[TestMethod]

public void Gradients()

{

var graph = tf.Graph().as_default();

var a = tf.constant(0.0);

var b = 2.0 * a;

Assert.AreEqual(b.name, "mul:0");

Assert.AreEqual(b.op.inputs[0].name, "mul/x:0");

Assert.AreEqual(b.op.inputs[1].name, "Const:0");

var ys = a + b;

Assert.AreEqual(ys.name, "add:0");

Assert.AreEqual(ys.op.inputs[0].name, "Const:0");

Assert.AreEqual(ys.op.inputs[1].name, "mul:0");

var g = tf.gradients(ys, new Tensor[] { a, b }, stop_gradients: new Tensor[] { a, b });

Assert.AreEqual(g[0].name, "gradients/Fill:0");

Assert.AreEqual(g[1].name, "gradients/Fill:0");

}

[TestMethod]

public void Gradient2x()

{

var graph = tf.Graph().as_default();

using (var sess = tf.Session(graph))

{

var x = tf.constant(7.0f);

var y = x * x * tf.constant(0.1f);

var grad = tf.gradients(y, x);

Assert.AreEqual(grad[0].name, "gradients/AddN:0");

float r = sess.run(grad[0]);

Assert.AreEqual(r, 1.4f);

}

}

[TestMethod]

public void Gradient3x()

{

var graph = tf.Graph().as_default();

tf_with(tf.Session(graph), sess => {

var x = tf.constant(7.0f);

var y = x * x * x * tf.constant(0.1f);

var grad = tf.gradients(y, x);

Assert.AreEqual(grad[0].name, "gradients/AddN:0");

float r = sess.run(grad[0]);

Assert.AreEqual(r, 14.700001f);

});

}

[TestMethod]

public void StridedSlice()

{

var graph = tf.Graph().as_default();

var t = tf.constant(np.array(new int[,,]

{

{

{ 11, 12, 13 },

{ 21, 22, 23 }

},

{

{ 31, 32, 33 },

{ 41, 42, 43 }

},

{

{ 51, 52, 53 },

{ 61, 62, 63 }

}

}));

var slice = tf.strided_slice(t,

begin: new[] { 0, 0, 0 },

end: new[] { 3, 2, 3 },

strides: new[] { 2, 2, 2 });

var y = slice + slice;

var g = tf.gradients(y, new Tensor[] { slice, slice });

using (var sess = tf.Session(graph))

{

var r = sess.run(slice);

Assert.IsTrue(Enumerable.SequenceEqual(r.shape, new[] { 2, 1, 2 }));

Assert.IsTrue(Enumerable.SequenceEqual(r[0].GetData<int>(), new[] { 11, 13 }));

Assert.IsTrue(Enumerable.SequenceEqual(r[1].GetData<int>(), new[] { 51, 53 }));

}

}

}

}