Image Classification
File size: 11,228 Bytes
b2df42b
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
"""

FlareSense v2 - Simple Usage Example



This script demonstrates how to use the FlareSense model to predict solar radio bursts

on e-Callisto data. The model is automatically downloaded from HuggingFace and cached locally.



Usage:

    python example_usage.py



The model will predict on a 15-minute window of data from a specific instrument.

"""

import torch
import numpy as np
from datetime import datetime
from huggingface_hub import hf_hub_download
from ecallisto_ng.data_download.downloader import get_ecallisto_data
from ecallisto_ng.data_processing.utils import subtract_constant_background
from ecallisto_ng.plotting.plotting import plot_spectrogram
from plotly.io import show
import torch.nn as nn
from torchvision import models
import os

# ============================================================================
# Model Definition
# ============================================================================

class GrayScaleResNet(nn.Module):
    """ResNet model adapted for grayscale images (single channel)."""
    
    def __init__(self, n_classes=1, resnet_type="resnet34"):
        super().__init__()
        
        # Load pretrained ResNet (without num_classes parameter)
        if resnet_type == "resnet34":
            self.resnet = models.resnet34(weights=models.ResNet34_Weights.DEFAULT)
        elif resnet_type == "resnet18":
            self.resnet = models.resnet18(weights=models.ResNet18_Weights.DEFAULT)
        elif resnet_type == "resnet50":
            self.resnet = models.resnet50(weights=models.ResNet50_Weights.DEFAULT)
        else:
            raise ValueError(f"Unsupported resnet_type: {resnet_type}")
        
        # Replace the final fully connected layer for our number of classes
        num_features = self.resnet.fc.in_features
        self.resnet.fc = nn.Linear(num_features, n_classes)
    
    def forward(self, x):
        # Convert grayscale (1 channel) to 3 channels by expanding
        if x.size(1) == 1:
            x = x.expand(-1, 3, -1, -1)
        return self.resnet(x)


# ============================================================================
# Data Processing Functions
# ============================================================================

def remove_background(df_spectrogram) -> torch.Tensor:
    """

    Remove constant background from spectrogram DataFrame.

    Uses the median of the first 300 timepoints as the background.

    

    Args:

        df_spectrogram: Pandas DataFrame with time as index and frequency as columns

        

    Returns:

        Torch tensor with background removed (frequency x time)

    """
    # Subtract constant background using ecallisto_ng function
    df_processed = subtract_constant_background(df_spectrogram, n=300)
    
    # Convert to numpy and transpose to (frequency, time)
    # DataFrame is (time, frequency), we need (frequency, time)
    array_processed = df_processed.values.T
    
    # Convert to torch tensor
    tensor = torch.from_numpy(array_processed).float()
    
    return tensor


def remove_background_median(spectrogram_tensor: torch.Tensor) -> torch.Tensor:
    """

    Remove row-wise median background from spectrogram tensor.

    This is applied AFTER the constant background subtraction.

    

    Args:

        spectrogram_tensor: Tensor of shape (frequency, time)

        

    Returns:

        Tensor with median background removed

    """
    # Calculate the median of each row (frequency band)
    median_values = torch.median(spectrogram_tensor, dim=1).values
    
    # Subtract the median from each row
    background_removed = spectrogram_tensor - median_values[:, None]
    
    return background_removed


def resize_spectrogram(spectrogram_tensor: torch.Tensor, target_size=(128, 512)) -> torch.Tensor:
    """

    Resize spectrogram to target size using bilinear interpolation.

    

    Args:

        spectrogram_tensor: Input tensor (frequency, time)

        target_size: Target size (height, width)

        

    Returns:

        Resized tensor (1, height, width)

    """
    # Add batch and channel dimensions for interpolation
    x = spectrogram_tensor.unsqueeze(0).unsqueeze(0)
    
    # Resize using bilinear interpolation
    resized = torch.nn.functional.interpolate(
        x, size=target_size, mode='bilinear', align_corners=False
    )
    
    # Remove batch dimension, keep channel dimension (1, H, W)
    return resized.squeeze(0)


def min_max_scale(tensor: torch.Tensor, feature_range=(0, 1)) -> torch.Tensor:
    """

    Apply Min-Max scaling to a tensor.

    

    Args:

        tensor: Input tensor

        feature_range: Desired range (default: (0, 1))

        

    Returns:

        Scaled tensor

    """
    min_val, max_val = feature_range
    tensor_min = tensor.min()
    tensor_max = tensor.max()
    
    # Avoid division by zero
    if tensor_max - tensor_min == 0:
        return torch.zeros_like(tensor)
    
    scaled_tensor = (tensor - tensor_min) / (tensor_max - tensor_min)
    scaled_tensor = scaled_tensor * (max_val - min_val) + min_val
    
    return scaled_tensor


def preprocess_spectrogram(df_spectrogram) -> torch.Tensor:
    """

    Complete preprocessing pipeline for a spectrogram DataFrame.

    This follows the exact same pipeline as the training code.

    

    Args:

        df_spectrogram: Pandas DataFrame (time x frequency) from get_ecallisto_data

        

    Returns:

        Preprocessed tensor ready for model input (1, 128, 512)

    """
    # Step 1: Remove constant background and convert to tensor (frequency x time)
    tensor = remove_background(df_spectrogram)
    
    # Step 2: Remove row-wise median background
    tensor = remove_background_median(tensor)
    
    # Step 3: Resize to target size (128, 512)
    # This uses normal_resize since custom_resize is False in config
    tensor = resize_spectrogram(tensor, target_size=(128, 512))
    
    # Step 4: Min-max scale to [0, 1]
    tensor = min_max_scale(tensor, feature_range=(0, 1))
    
    return tensor


# ============================================================================
# Model Loading and Prediction
# ============================================================================

def load_flaresense_model(device="cpu"):
    """

    Load the FlareSense model from HuggingFace Hub.

    The model is automatically downloaded and cached locally.

    

    Args:

        device: Device to load model on ('cpu' or 'cuda')

        

    Returns:

        Loaded model in evaluation mode

    """
    # Model configuration (from best_v2.yml)
    REPO_ID = "i4ds/flaresense-v2"
    MODEL_FILENAME = "model.ckpt"
    RESNET_TYPE = "resnet34"
    
    print(f"Downloading model from {REPO_ID}...")
    checkpoint_path = hf_hub_download(repo_id=REPO_ID, filename=MODEL_FILENAME)
    print(f"Model cached at: {checkpoint_path}")
    
    # Initialize model
    model = GrayScaleResNet(n_classes=1, resnet_type=RESNET_TYPE)
    
    # Load checkpoint
    checkpoint = torch.load(checkpoint_path, weights_only=True, map_location=device)
    if "state_dict" in checkpoint:
        state_dict = checkpoint["state_dict"]
    else:
        state_dict = checkpoint
    
    # Remove '_orig_mod.' prefix from keys (added by torch.compile)
    new_state_dict = {}
    for key, value in state_dict.items():
        new_key = key.replace("_orig_mod.", "")
        new_state_dict[new_key] = value
    
    model.load_state_dict(new_state_dict)
    
    # Set to evaluation mode and move to device
    model.eval()
    model.to(device)
    
    print(f"Model loaded successfully on {device}")
    return model


def sigmoid(x, temperature=0.4974):
    """

    Convert logit to probability using temperature-scaled sigmoid.

    

    Args:

        x: Logit value

        temperature: Temperature parameter for calibration

        

    Returns:

        Probability [0, 1]

    """
    return 1 / (1 + np.exp(-x / temperature))


def predict_burst(model, df_spectrogram, device="cpu"):
    """

    Predict solar radio burst on a single spectrogram DataFrame.

    

    Args:

        model: Loaded FlareSense model

        df_spectrogram: Pandas DataFrame (time x frequency) from get_ecallisto_data

        device: Device to run prediction on

        

    Returns:

        tuple: (logit, probability)

            - logit: Raw model output

            - probability: Calibrated probability [0, 1]

    """
    # Preprocess the DataFrame
    input_tensor = preprocess_spectrogram(df_spectrogram)
    
    # Add batch dimension and move to device
    input_batch = input_tensor.unsqueeze(0).to(device)
    
    # Predict
    with torch.no_grad():
        logit = model(input_batch).squeeze().item()
    
    # Convert to probability
    probability = sigmoid(logit)
    
    return logit, probability


# ============================================================================
# Main Example
# ============================================================================

def main():
    """Main example demonstrating how to use FlareSense for prediction."""
    
    # Configuration
    device = "cuda" if torch.cuda.is_available() else "cpu"
    print(f"Using device: {device}\n")
    
    # Example: Predict on data from May 7, 2021
    # Create a 15-minute window centered around 03:40:30
    # This gives us exactly 15 minutes: 03:33:00 to 03:48:00
    start_time = datetime(2021, 5, 7, 3, 33, 0)
    end_time = datetime(2021, 5, 7, 3, 48, 0)
    
    instrument = "Australia-ASSA_01"
    
    print(f"Example prediction on instrument: {instrument}")
    
    # Load model (downloaded and cached automatically)
    model = load_flaresense_model(device=device)
    
    # Fetch data from e-Callisto
    print(f"Fetching data from e-Callisto...")
    df_dict = get_ecallisto_data(start_time, end_time, instrument)
    
    
    df_spectrogram = df_dict[instrument]

    print(f"Data shape: {df_spectrogram.shape} (time x frequency)")
    print(f"Time range: {df_spectrogram.index[0]} to {df_spectrogram.index[-1]}")
    print(f"Frequency range: {df_spectrogram.columns[0]:.2f} - {df_spectrogram.columns[-1]:.2f} MHz\n")
    
    # Predict (pass the DataFrame directly)
    print("Running prediction...")
    logit, probability = predict_burst(model, df_spectrogram, device=device)
    
    # Display results
    print("\n" + "="*60)
    print("PREDICTION RESULTS")
    print("="*60)
    print(f"Logit:       {logit:.4f}")
    print(f"Probability: {probability:.4f} ({probability*100:.2f}%)")
    burst_detected = probability > 0.5
    print(f"Prediction:  {'BURST DETECTED ☀️' if burst_detected else 'No burst'}")
    print("="*60)
    
    # Plot and save the spectrogram
    print("\nGenerating spectrogram plot...")
    df_processed = subtract_constant_background(df_dict[instrument])

    
    # Show the plot
    fig = plot_spectrogram(df_processed)
    show(fig)


if __name__ == "__main__":
    main()