Tfjs: TF Node backend does not support normalized logits passed to multinomial

[AndreMaz]

TensorFlow.js version

V1.5.1

Describe the problem or feature request

Just stumbled on this error:
TF Node backend does not support normalized logits passed to multinomial

https://github.com/tensorflow/tfjs/blob/c2d556415db8d9fb611a69a77a6288678ab0f86d/tfjs-node/src/nodejs_kernel_backend.ts#L1561-L1568

I know that as a workaround I can unnormalize the inputs, but what's the actual limitation? Why the node backend doesn't support this?

[kangyizhang]

This is because TensorFlow C library multinomial op only support unnormalized logits: https://www.tensorflow.org/api_docs/cc/class/tensorflow/ops/multinomial

FYI tfjs-node library is using TensorFlow C library under the hood.