6. The configuration you specified appears. Enter y to approve or n to cancel.
7. When the ctpu up command has finished executing, verify that your shell prompt has changed from username@project to username@tpuname. This change shows that you are now logged into your Compute Engine VM.
```
gcloud compute ssh vm-name --zone=europe-west4-a
(vm)$ export TPU_NAME=vm-name
```
As you continue these instructions, run each command that begins with `(vm)$` in your VM session window.
## Prepare the Dataset
1. From your Compute Engine virtual machine (VM), install requirements.txt.
This tutorial uses the General Language Understanding Evaluation (GLUE) benchmark to evaluate and analyze the performance of the model. The GLUE data is provided for this tutorial at gs://cloud-tpu-checkpoints/bert/classification.
## Define parameter values
Next, define several parameter values that are required when you train and evaluate your model:
The training takes approximately 1 hour on a v3-8 TPU. When script completes, you should see results similar to the following:
```
Training Summary:
{'train_loss': 0.28142181038856506,
'last_train_metrics': 0.9467429518699646,
'eval_metrics': 0.8599063158035278,
'total_training_steps': 36813}
```
## Clean up
To avoid incurring charges to your GCP account for the resources used in this topic:
1. Disconnect from the Compute Engine VM:
```
(vm)$ exit
```
2. In your Cloud Shell, run ctpu delete with the --zone flag you used when you set up the Cloud TPU to delete your Compute Engine VM and your Cloud TPU:
```
$ ctpu delete --zone=your-zone
```
3. Run ctpu status specifying your zone to make sure you have no instances allocated to avoid unnecessary charges for TPU usage. The deletion might take several minutes. A response like the one below indicates there are no more allocated instances:
```
$ ctpu status --zone=your-zone
```
4. Run gsutil as shown, replacing your-bucket with the name of the Cloud Storage bucket you created for this tutorial:
The pre-trained ResNet-50 checkpoint can be downloaded [here](https://storage.cloud.google.com/cloud-tpu-checkpoints/model-garden-vision/detection/resnet50-2018-02-07.tar.gz).
The pre-trained ResNet-50 checkpoint can be downloaded [here](https://storage.cloud.google.com/cloud-tpu-checkpoints/model-garden-vision/detection/resnet50-2018-02-07.tar.gz).
The pre-trained ResNet-50 checkpoint can be downloaded [here](https://storage.cloud.google.com/cloud-tpu-checkpoints/model-garden-vision/detection/resnet50-2018-02-07.tar.gz).
`MODEL_DIR` needs to point to the trained path of ShapeMask model.
Change `strategy_type=mirrored` and `num_gpus=1` to run on a GPU.
Note: The JSON groundtruth file is useful for [COCO dataset](http://cocodataset.org/#home) and can be
downloaded from the [COCO website](http://cocodataset.org/#download). For custom dataset, it is unncessary because the groundtruth can be included in the TFRecord files.
## References
1.[Focal Loss for Dense Object Detection](https://arxiv.org/abs/1708.02002).
Tsung-Yi Lin, Priya Goyal, Ross Girshick, Kaiming He, and Piotr Dollár. IEEE
International Conference on Computer Vision (ICCV), 2017.