# Implement Problem
`Linux` `Windows` `Ascend` `GPU` `CPU` `Environment Preparation` `Basic` `Intermediate`
[](https://gitee.com/mindspore/docs/blob/r1.3/docs/mindspore/faq/source_en/implement_problem.md)
**Q: What is the function of the `.meta` file generated after the model is saved using MindSpore? Can the `.meta` file be used to import the graph structure?**
A: The `.meta` file is a built graph structure. However, this structure cannot be directly imported currently. If you do not know the graph structure, you still need to use the MindIR file to import the network.
**Q: Can the `yolov4-tiny-3l.weights` model file be directly converted into a MindSpore model?**
A: No. You need to convert the parameters trained by other frameworks into the MindSpore format, and then convert the model file into a MindSpore model.
**Q: Why an error is reported when MindSpore is used to set `model.train`?**
```python
model.train(1, dataset, callbacks=LossMonitor(1), dataset_sink_mode=True)
model.train(1, dataset, callbacks=LossMonitor(1), dataset_sink_mode=False)
```
A: If the offloading mode has been set, it cannot be set to non-offloading mode. This is a restriction on the running mechanism.
**Q: What should I pay attention to when using MindSpore to train a model in the `eval` phase? Can the network and parameters be loaded directly? Does the optimizer need to be used in the model?**
A: It mainly depends on what is required in the `eval` phase. For example, the output of the `eval` network of the image classification task is the probability value of each class, and the `acc` is computed with the corresponding label.
In most cases, the training network and parameters can be directly reused. Note that the inference mode needs to be set.
```python
net.set_train(False)
```
The optimizer is not required in the `eval` phase. However, if the `model.eval` API of MindSpore needs to be used, the `loss function` needs to be configured. For example:
```python
# Define a model.
model = Model(net, loss_fn=loss, metrics={'top_1_accuracy', 'top_5_accuracy'})
# Evaluate the model.
res = model.eval(dataset)
```
**Q: How do I use `param_group` in SGD to reduce the learning rate?**
A: To change the value according to `epoch`, use [Dynamic LR](https://mindspore.cn/docs/api/en/r1.3/api_python/mindspore.nn.html#dynamic-lr) and set `step_per_epoch` to `step_size`. To change the value according to `step`, set `step_per_epoch` to 1. You can also use [LearningRateSchedule](https://mindspore.cn/docs/api/en/r1.3/api_python/mindspore.nn.html#dynamic-learning-rate).
**Q: How do I modify parameters (such as the dropout value) on MindSpore?**
A: When building a network, use `if self.training: x = dropput(x)`. When reasoning, set `network.set_train(mode_false)` before execution to disable the dropout function. During training, set `network.set_train(mode_false)` to True to enable the dropout function.
**Q: How do I view the number of model parameters?**
A: You can load the checkpoint to count the parameter number. Variables in the momentum and optimizer may be counted, so you need to filter them out.
You can refer to the following APIs to collect the number of network parameters:
```python
def count_params(net):
"""Count number of parameters in the network
Args:
net (mindspore.nn.Cell): Mindspore network instance
Returns:
total_params (int): Total number of trainable params
"""
total_params = 0
for param in net.trainable_params():
total_params += np.prod(param.shape)
return total_params
```
[Script Link](https://gitee.com/mindspore/mindspore/blob/r1.3/model_zoo/research/cv/tinynet/src/utils.py).
**Q: How do I monitor the loss during training and save the training parameters when the `loss` is the lowest?**
A: You can customize a `callback`.For details, see the writing method of `ModelCheckpoint`. In addition, the logic for determining loss is added.
```python
class EarlyStop(Callback):
def __init__(self):
self.loss = None
def step_end(self, run_context):
loss = ****(get current loss)
if (self.loss == None or loss < self.loss):
self.loss = loss
# do save ckpt
```
**Q: How do I obtain the expected `feature map` when `nn.Conv2d` is used?**
A: For details about how to derive the `Conv2d shape`, click [here](https://www.mindspore.cn/docs/api/en/r1.3/api_python/nn/mindspore.nn.Conv2d.html#mindspore.nn.Conv2d) Change `pad_mode` of `Conv2d` to `same`. Alternatively, you can calculate the `pad` based on the Conv2d shape derivation formula to keep the `shape` unchanged. Generally, the pad is `(kernel_size-1)//2`.
**Q: Can MindSpore be used to customize a loss function that can return multiple values?**
A: After customizing the `loss function`, you need to customize `TrainOneStepCell`. The number of `sens` for implementing gradient calculation is the same as the number of `network` outputs. For details, see the following:
```python
net = Net()
loss_fn = MyLoss()
loss_with_net = MyWithLossCell(net, loss_fn)
train_net = MyTrainOneStepCell(loss_with_net, optim)
model = Model(net=train_net, loss_fn=None, optimizer=None)
```
**Q: How does MindSpore implement the early stopping function?**
A: You can customize the `callback` method to implement the early stopping function.
Example: When the loss value decreases to a certain value, the training stops.
```python
class EarlyStop(Callback):
def __init__(self, control_loss=1):
super(EarlyStep, self).__init__()
self._control_loss = control_loss
def step_end(self, run_context):
cb_params = run_context.original_args()
loss = cb_params.net_outputs
if loss.asnumpy() < self._control_loss:
# Stop training.
run_context._stop_requested = True
stop_cb = EarlyStop(control_loss=1)
model.train(epoch_size, ds_train, callbacks=[stop_cb])
```
**Q: After a model is trained, how do I save the model output in text or `npy` format?**
A: The network output is `Tensor`. You need to use the `asnumpy()` method to convert the `Tensor` to `NumPy` and then save the data. For details, see the following:
```python
out = net(x)
np.save("output.npy", out.asnumpy())
```
**Q: What can I do if an error "Create python object \`\` failed, only support create Cell or Primitive object." is reported?**
A: Currently in graph mode, the `construct` function (or the function decorated by the `@ms_function` decorator) only supports the construction of `Cell` and `Primitive object`. The construction of `Tensor` is not supported, that is, the syntax `x = Tensor(args...)` is not supported.
If it is a constant tensor, please define it in the function `__init__`. If not, you can use the `@constexpr` decorator to modify the function and generate the `Tensor` in the function.
Please see the usage of `@constexpr` in .
The constant `Tensor` used on the network can be used as a network attribute and defined in `init`, that is, `self.x = Tensor(args...)`. Then the constant can be used in the `construct` function (or the function decorated by the `@ms_function` decorator).
In the following example, `Tensor` of `shape = (3, 4), dtype = int64` is generated by `@constexpr`.
```python
@constexpr
def generate_tensor():
return Tensor(np.ones((3, 4).astype(np.int64)))
```
**Q: What can I do if an error "'self.xx' should be defined in the class '__init__' function." is reported?**
A: If you want to assign for a class member such as `self.xx` in the function `construct`, `self.xx` must have been defined to a [`Parameter`]() type firstly while the other types are not supported. But the local variable `xx` is not under the regulation.
**Q: What can I do if an error "This comparator 'AnyValue' is not supported. For statement 'is', only support compare with 'None', 'False' or 'True'" is reported?**
A: For the syntax `is` or `is not`, currently `MindSpore` only supports comparisons with `True`, `False` and `None`. Other types, such as strings, are not supported.
**Q: What can I do if an error "MindSpore does not support comparison with operators more than one now, ops size =2" is reported?**
A: For comparison statements, `MindSpore` supports at most one operator. Please modify your code. For example, you can use `1 < x and x < 3` to take the place of `1 < x < 3`.
**Q: What can I do if an error "TypeError: The function construct need 1 positional argument and 0 default argument, but provided 2" is reported?**
A: When you call the instance of a network, the function `construct` will be executed. And the program will check the number of parameters required by the function `construct` and the number of parameters actually given. If they are not equal, the above exception will be thrown.
Please check your code to make sure they are equal.
**Q: What can I do if an error "Type Join Failed" or "Shape Join Failed" is reported?**
A: In the inference stage of front-end compilation, the abstract types of nodes, including `type` and `shape`, will be inferred. Common abstract types include `AbstractScalar`, `AbstractTensor`, `AbstractFunction`, `AbstractTuple`, `AbstractList`, etc. In some scenarios, such as multi-branch scenarios, the abstract types of the return values of different branches will be joined to infer the abstract type of the returned result. If these abstract types do not match, or `type`/`shape` are inconsistent, the above exception will be thrown.
When an error similar to "Type Join Failed: dtype1 = Float32, dtype2 = Float16" appears, it means that the data types are inconsistent, resulting in an exception when joining abstract. According to the provided data types and code line, the error can be quickly located. In addition, the specific abstract information and node information are provided in the error message. You can view the MindIR information through the `analyze_fail.dat` file to locate and solve the problem. For specific introduction of MindIR, please refer to [MindSpore IR (MindIR)](https://www.mindspore.cn/docs/note/en/r1.3/design/mindir.html). The code sample is as follows:
```python
import numpy as np
import mindspore as ms
import mindspore.ops as ops
from mindspore import nn, Tensor, context
context.set_context(mode=context.GRAPH_MODE)
class Net(nn.Cell):
def __init__(self):
super().__init__()
self.relu = ops.ReLU()
self.cast = ops.Cast()
def construct(self, x, a, b):
if a > b:
return self.relu(x)
else:
return self.cast(self.relu(x), ms.float16)
input_x = Tensor(np.random.rand(2, 3, 4, 5).astype(np.float32))
input_a = Tensor(2, ms.float32)
input_b = Tensor(6, ms.float32)
net = Net()
out_me = net(input_x, input_a, input_b)
```
The result is as follows:
```text
TypeError: The return values of different branches do not match. Type Join Failed: dtype1 = Float32, dtype2 = Float16. The abstract type of the return value of the current branch is AbstractTensor(shape: (2, 3, 4, 5), element: AbstractScalar(Type: Float16, Value: AnyValue, Shape: NoShape), value_ptr: 0x32ed00e0, value: AnyValue), and that of the previous branch is AbstractTensor(shape: (2, 3, 4, 5), element: AbstractScalar(Type: Float32, Value: AnyValue, Shape: NoShape), value_ptr: 0x32ed00e0, value: AnyValue). Please check the node construct.4:[CNode]5{[0]: [CNode]6}, true branch: ✓construct.2, false branch: ✗construct.3. trace:
In file test_join.py(14)/ if a > b:/
The function call stack (See file 'analyze_fail.dat' for more details):
# 0 In file test_join.py(14)
if a > b:
```
When an error similar to "Shape Join Failed: shape1 = (2, 3, 4, 5), shape2 = ()" appears, it means that the shapes are inconsistent, resulting in an exception when joining abstract. The code sample is as follows:
```python
import numpy as np
import mindspore as ms
import mindspore.ops as ops
from mindspore import nn, Tensor, context
context.set_context(mode=context.GRAPH_MODE)
class Net(nn.Cell):
def __init__(self):
super().__init__()
self.relu = ops.ReLU()
self.reducesum = ops.ReduceSum()
def construct(self, x, a, b):
if a > b:
return self.relu(x)
else:
return self.reducesum(x)
input_x = Tensor(np.random.rand(2, 3, 4, 5).astype(np.float32))
input_a = Tensor(2, ms.float32)
input_b = Tensor(6, ms.float32)
net = Net()
out = net(input_x, input_a, input_b)
```
The result is as follows:
```text
ValueError: The return values of different branches do not match. Shape Join Failed: shape1 = (2, 3, 4, 5), shape2 = (). The abstract type of the return value of the current branch is AbstractTensor(shape: (), element: AbstractScalar(Type: Float32, Value: AnyValue, Shape: NoShape), value_ptr: 0x239b5120, value: AnyValue), and that of the previous branch is AbstractTensor(shape: (2, 3, 4, 5), element: AbstractScalar(Type: Float32, Value: AnyValue, Shape: NoShape), value_ptr: 0x239b5120, value: AnyValue). Please check the node construct.4:[CNode]5{[0]: [CNode]6}, true branch: ✓construct.2, false branch: ✗construct.3. trace:
In file test_join1.py(14)/ if a > b:/
The function call stack (See file 'analyze_fail.dat' for more details):
# 0 In file test_join1.py(14)
if a > b:
```
When an error similar to "Type Join Failed: abstract type AbstractTensor can not join with AbstractTuple" appears, it means that the two abstract types are mismatched. You need to review the code and modify it based on the provided code line and other error information.
**Q: Can the `vgg16` model be loaded and transferred on a GPU using the Hub?**
A: Yes, but you need to manually modify the following two arguments:
```python
# Add the **kwargs argument as follows:
def vgg16(num_classes=1000, args=None, phase="train", **kwargs):
```
```python
# Add the **kwargs argument as follows:
net = Vgg(cfg['16'], num_classes=num_classes, args=args, batch_norm=args.batch_norm, phase=phase, **kwargs)
```
**Q: How to obtain middle-layer features of a VGG model?**
A: Obtaining the middle-layer features of a network is not closely related to the specific framework. For the `vgg` model defined in `torchvison`, the `features` field can be used to obtain the middle-layer features. The `vgg` source code of `torchvison` is as follows:
```python
class VGG(nn.Module):
def __init__(self, features, num_classes=1000, init_weights=True):
super(VGG, self).__init__()
self.features = features
self.avgpool = nn.AdaptiveAvgPool2d((7, 7))
```
The `vgg16` defined in ModelZoo of MindSpore can be obtained through the `layers` field as follows:
```python
network = vgg16()
print(network.layers)
```
**Q: When MindSpore is used for model training, there are four input parameters for `CTCLoss`: `inputs`, `labels_indices`, `labels_values`, and `sequence_length`. How do I use `CTCLoss` for model training?**
A: The `dataset` received by the defined `model.train` API can consist of multiple pieces of data, for example, (`data1`, `data2`, `data3`, ...). Therefore, the `dataset` can contain `inputs`, `labels_indices`, `labels_values`, and `sequence_length` information. You only need to define the dataset in the corresponding format and transfer it to `model.train`. For details, see [Data Processing API](https://www.mindspore.cn/docs/programming_guide/en/r1.3/dataset_loading.html).
**Q: How do I load the PyTorch weight to MindSpore during model transfer?**
A: First, enter the `PTH` file of PyTorch. Take `ResNet-18` as an example. The network structure of MindSpore is the same as that of PyTorch. After transferring, the file can be directly loaded to the network. Only `BN` and `Conv2D` are used during loading. If the network names of MindSpore and PyTorch at other layers are different, change the names to the same.
**Q: What are the available recommendation or text generation networks or models provided by MindSpore?**
A: Currently, recommendation models such as Wide & Deep, DeepFM, and NCF are under development. In the natural language processing (NLP) field, Bert\_NEZHA is available and models such as MASS are under development. You can rebuild the network into a text generation network based on the scenario requirements. Please stay tuned for updates on the [MindSpore Model Zoo](https://gitee.com/mindspore/mindspore/tree/r1.3/model_zoo).
**Q: How do I use MindSpore to fit functions such as $f(x)=a \times sin(x)+b$?**
A: The following is based on the official MindSpore linear fitting case.
```python
# The fitting function is: f(x)=2*sin(x)+3.
import numpy as np
from mindspore import dataset as ds
from mindspore.common.initializer import Normal
from mindspore import nn, Model, context
from mindspore.train.callback import LossMonitor
context.set_context(mode=context.GRAPH_MODE, device_target="CPU")
def get_data(num, w=2.0, b=3.0):
# f(x)=w * sin(x) + b
# f(x)=2 * sin(x) +3
for i in range(num):
x = np.random.uniform(-np.pi, np.pi)
noise = np.random.normal(0, 1)
y = w * np.sin(x) + b + noise
yield np.array([np.sin(x)]).astype(np.float32), np.array([y]).astype(np.float32)
def create_dataset(num_data, batch_size=16, repeat_size=1):
input_data = ds.GeneratorDataset(list(get_data(num_data)), column_names=['data','label'])
input_data = input_data.batch(batch_size)
input_data = input_data.repeat(repeat_size)
return input_data
class LinearNet(nn.Cell):
def __init__(self):
super(LinearNet, self).__init__()
self.fc = nn.Dense(1, 1, Normal(0.02), Normal(0.02))
def construct(self, x):
x = self.fc(x)
return x
if __name__ == "__main__":
num_data = 1600
batch_size = 16
repeat_size = 1
lr = 0.005
momentum = 0.9
net = LinearNet()
net_loss = nn.loss.MSELoss()
opt = nn.Momentum(net.trainable_params(), lr, momentum)
model = Model(net, net_loss, opt)
ds_train = create_dataset(num_data, batch_size=batch_size, repeat_size=repeat_size)
model.train(1, ds_train, callbacks=LossMonitor(), dataset_sink_mode=False)
print(net.trainable_params()[0], "\n%s" % net.trainable_params()[1])
```
**Q: How do I use MindSpore to fit quadratic functions such as $f(x)=ax^2+bx+c$?**
A: The following code is referenced from the official [MindSpore tutorial code](https://gitee.com/mindspore/docs/blob/r1.3/docs/sample_code/linear_regression.py).
Modify the following items to fit $f(x) = ax^2 + bx + c$:
1. Dataset generation.
2. Network fitting.
3. Optimizer.
The following explains detailed information about the modification:
```python
# The selected optimizer does not support CPUs. Therefore, the GPU computing platform is used for training. You need to install MindSpore of the GPU version.
context.set_context(mode=context.GRAPH_MODE, device_target="GPU")
# Assume that the function to be fitted is f(x)=2x^2+3x+4. Modify the data generation function as follows:
def get_data(num, a=2.0, b=3.0 ,c = 4):
for i in range(num):
x = np.random.uniform(-10.0, 10.0)
noise = np.random.normal(0, 1)
# For details about how to generate the value of y, see the to-be-fitted objective function ax^2+bx+c.
y = x * x * a + x * b + c + noise
# When fitting a*x^2 + b*x +c, a and b are weight parameters, and c is the offset parameter bias. The training data corresponding to the two weights is x^2 and x, respectively. Therefore, the dataset generation mode is changed as follows:
yield np.array([x*x, x]).astype(np.float32), np.array([y]).astype(np.float32)
def create_dataset(num_data, batch_size=16, repeat_size=1):
input_data = ds.GeneratorDataset(list(get_data(num_data)), column_names=['data','label'])
input_data = input_data.batch(batch_size)
input_data = input_data.repeat(repeat_size)
return input_data
class LinearNet(nn.Cell):
def __init__(self):
super(LinearNet, self).__init__()
# Two training parameters are input for the full connection function. Therefore, the input value is changed to 2. The first Normal(0.02) automatically allocates random weights to the two input parameters, and the second Normal is the random bias.
self.fc = nn.Dense(2, 1, Normal(0.02), Normal(0.02))
def construct(self, x):
x = self.fc(x)
return x
if __name__ == "__main__":
num_data = 1600
batch_size = 16
repeat_size = 1
lr = 0.005
momentum = 0.9
net = LinearNet()
net_loss = nn.loss.MSELoss()
# RMSProp optimizer with better effect is selected for quadratic function fitting. Currently, Ascend and GPU computing platforms are supported.
opt = nn.RMSProp(net.trainable_params(), learning_rate=0.1)
model = Model(net, net_loss, opt)
ds_train = create_dataset(num_data, batch_size=batch_size, repeat_size=repeat_size)
model.train(1, ds_train, callbacks=LossMonitor(), dataset_sink_mode=False)
print(net.trainable_params()[0], "\n%s" % net.trainable_params()[1])
```
**Q: How do I execute a single `ut` case in `mindspore/tests`?**
A: `ut` cases are usually based on the MindSpore package of the debug version, which is not provided on the official website. You can run `sh build.sh` to compile the source code and then run the `pytest` command. The compilation in debug mode does not depend on the backend. Run the `sh build.sh -t on` command. For details about how to execute cases, see the `tests/runtest.sh` script.
**Q: For Ascend users, how to get more detailed logs when the `run task error` is reported?**
A: Use the msnpureport tool to set the on-device log level. The tool is stored in `/usr/local/Ascend/driver/tools/msnpureport`.
```bash
- Global: /usr/local/Ascend/driver/tools/msnpureport -g info
```
```bash
- Module-level: /usr/local/Ascend/driver/tools/msnpureport -m SLOG:error
```
```bash
- Event-level: /usr/local/Ascend/driver/tools/msnpureport -e disable/enable
```
```bash
- Multi-device ID-level: /usr/local/Ascend/driver/tools/msnpureport -d 1 -g warning
```
Assume that the value range of deviceID is [0, 7], and `devices 0–3` and `devices 4–7` are on the same OS. `Devices 0–3` share the same log configuration file and `devices 4–7` share the same configuration file. In this way, changing the log level of any device (for example device 0) will change that of other devices (for example `devices 1–3`). This rule also applies to `devices 4–7`.
After the driver package is installed (assuming that the installation path is /usr/local/HiAI and the execution file `msnpureport.exe` is in the C:\ProgramFiles\Huawei\Ascend\Driver\tools\ directory on Windows), run the command in the /home/shihangbo/ directory to export logs on the device to the current directory and store logs in a folder named after the timestamp.
**Q: How do I change hyperparameters for calculating loss values during neural network training?**
A: Sorry, this function is not available yet. You can find the optimal hyperparameters by training, redefining an optimizer, and then training.
**Q: What should I do when error `error while loading shared libraries: libge_compiler.so: cannot open shared object file: No such file or directory` prompts during application running?**
A: While installing Ascend 310 AI Processor software packages，the `CANN` package should install the full-featured `toolkit` version instead of the `nnrt` version.
**Q: Why does context.set_ps_context(enable_ps=True) in model_zoo/official/cv/resnet/train.py in the MindSpore code have to be set before init?**
A: In MindSpore Ascend mode, if init is called first, then all processes will be allocated cards, but in parameter server training mode, the server does not need to allocate cards, then the worker and server will use the same card, resulting in an error: Hccl dependent tsd is not open.