Specify fftLength in rfft op

[Lewuathe]

In order to implement stft without introducing future breaking change, rfft should be able to get fftLength param in advance. That is compatible with TensorFlow core rfft ops.

See: https://www.tensorflow.org/api_docs/python/tf/signal/rfft

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This change is 

[nsthorat]

Reviewable status: 0 of 1 approvals obtained (waiting on @Lewuathe)

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src/ops/spectral_ops.ts, line 109 at r1 (raw file):

 * @doc {heading: 'Operations', subheading: 'Spectral', namespace: 'spectral'}
 */
function rfft_(input: Tensor, fftLength: number = null): Tensor {

no need to specify null here

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src/ops/spectral_ops.ts, line 109 at r1 (raw file):

 * @doc {heading: 'Operations', subheading: 'Spectral', namespace: 'spectral'}
 */
function rfft_(input: Tensor, fftLength: number = null): Tensor {

in tensorflow fftLength is a Tensor, can you make this a TensorLike and then convert it?

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src/ops/spectral_ops_test.ts, line 219 at r1 (raw file):

  it('should return the same value without any fftLength', async () => {
    const t1Real = tf.tensor1d([-3, -2, -1, 1, 2, 3]);
    expectArraysClose(await tf.spectral.rfft(t1Real, 6).data(), [

can you pull the numbers to a constant const fftLength = 4; for readability

[Lewuathe]

Reviewable status: 0 of 1 approvals obtained (waiting on @nsthorat)

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src/ops/spectral_ops.ts, line 109 at r1 (raw file):

Previously, nsthorat (Nikhil Thorat) wrote…

no need to specify null here

But otherwise, it breaks the compatibility. I mean we always need to pass two arguments for rfft.

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src/ops/spectral_ops.ts, line 109 at r1 (raw file):

Previously, nsthorat (Nikhil Thorat) wrote…

in tensorflow fftLength is a Tensor, can you make this a TensorLike and then convert it?

How can we safely convert TensorLike to number? Is there any common way?

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src/ops/spectral_ops_test.ts, line 219 at r1 (raw file):

Previously, nsthorat (Nikhil Thorat) wrote…

can you pull the numbers to a constant const fftLength = 4; for readability

Sure will do.

[nsthorat]

Reviewable status: 0 of 1 approvals obtained (waiting on @Lewuathe)

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src/ops/spectral_ops.ts, line 109 at r1 (raw file):

Previously, Lewuathe (Kai Sasaki) wrote…

But otherwise, it breaks the compatibility. I mean we always need to pass two arguments for rfft.

I just mean this with a question mark:

rfft_(input: Tensor, fftLength?: number)

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src/ops/spectral_ops.ts, line 109 at r1 (raw file):

Previously, Lewuathe (Kai Sasaki) wrote…

How can we safely convert TensorLike to number? Is there any common way?

Ah, didn't realize the shape was a function of this. This is fine for now.

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src/ops/spectral_ops_test.ts, line 219 at r1 (raw file):

Previously, Lewuathe (Kai Sasaki) wrote…

Sure will do.

Let me know when this is done.

[Lewuathe]

Reviewable status: 0 of 1 approvals obtained (waiting on @Lewuathe and @nsthorat)

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src/ops/spectral_ops.ts, line 109 at r1 (raw file):

Previously, nsthorat (Nikhil Thorat) wrote…

I just mean this with a question mark:

rfft_(input: Tensor, fftLength?: number)

Oh, I see. Thanks will do.

[Lewuathe]

@nsthorat I updated accordingly. Could you take a look again?

[nsthorat]

Reviewed 2 of 2 files at r2.
Reviewable status: complete! 1 of 1 approvals obtained

[nsthorat]

Thanks @Lewuathe as always high quality PR :)