scirs2_transform/
gpu.rs

1//! GPU-accelerated transformations
2//!
3//! This module provides GPU-accelerated implementations of dimensionality reduction
4//! and matrix operations. Currently provides basic stubs with CPU fallback.
5
6use crate::error::{Result, TransformError};
7use scirs2_core::gpu::{GpuBackend, GpuContext};
8use scirs2_core::ndarray::{Array1, Array2, ArrayView2};
9use scirs2_core::validation::{check_not_empty, check_positive, checkarray_finite};
10
11/// GPU-accelerated Principal Component Analysis
12#[cfg(feature = "gpu")]
13pub struct GpuPCA {
14    /// Number of components to compute
15    pub n_components: usize,
16    /// Whether to center the data
17    pub center: bool,
18    /// Principal components (loading vectors)
19    pub components: Option<Array2<f64>>,
20    /// Explained variance for each component
21    pub explained_variance: Option<Array1<f64>>,
22    /// Mean values for centering
23    pub mean: Option<Array1<f64>>,
24    /// GPU context for GPU operations
25    gpu_context: Option<GpuContext>,
26}
27
28#[cfg(feature = "gpu")]
29impl GpuPCA {
30    /// Create a new GPU PCA instance
31    ///
32    /// # Arguments
33    ///
34    /// * `n_components` - Number of principal components to compute
35    ///
36    /// # Returns
37    ///
38    /// Returns a new GpuPCA instance with GPU context initialized
39    ///
40    /// # Errors
41    ///
42    /// Returns an error if GPU initialization fails or if n_components is 0
43    ///
44    /// # Examples
45    ///
46    /// ```
47    /// # use scirs2_transform::gpu::GpuPCA;
48    /// # fn main() -> Result<(), Box<dyn std::error::Error>> {
49    /// let pca = GpuPCA::new(5)?;
50    /// # Ok(())
51    /// # }
52    /// ```
53    pub fn new(n_components: usize) -> Result<Self> {
54        check_positive(n_components, "n_components")?;
55
56        let gpu_context = GpuContext::new(GpuBackend::preferred()).map_err(|e| {
57            TransformError::ComputationError(format!("Failed to initialize GPU: {}", e))
58        })?;
59
60        Ok(GpuPCA {
61            n_components,
62            center: true,
63            components: None,
64            explained_variance: None,
65            mean: None,
66            gpu_context: Some(gpu_context),
67        })
68    }
69
70    /// Fit the PCA model on GPU
71    ///
72    /// Currently this is a placeholder implementation that will return an error
73    /// indicating that full GPU PCA support is not yet implemented.
74    ///
75    /// # Arguments
76    ///
77    /// * `x` - Input data matrix with shape (n_samples, n_features)
78    ///
79    /// # Errors
80    ///
81    /// Returns an error indicating that GPU PCA is not fully implemented yet
82    ///
83    /// # Examples
84    ///
85    /// ```should_panic
86    /// # use scirs2_transform::gpu::GpuPCA;
87    /// # use scirs2_core::ndarray::Array2;
88    /// # fn main() -> Result<(), Box<dyn std::error::Error>> {
89    /// let mut pca = GpuPCA::new(2)?;
90    /// let data = Array2::zeros((100, 5));
91    /// // This will return an error indicating GPU PCA is not implemented
92    /// pca.fit(&data.view())?;
93    /// # Ok(())
94    /// # }
95    /// ```
96    pub fn fit(&mut self, x: &ArrayView2<f64>) -> Result<()> {
97        check_not_empty(x, "x")?;
98        checkarray_finite(x, "x")?;
99
100        // Validate input
101        let (n_samples, n_features) = x.dim();
102        if self.n_components > n_features.min(n_samples) {
103            return Err(TransformError::InvalidInput(
104                "n_components cannot be larger than min(n_samples, n_features)".to_string(),
105            ));
106        }
107
108        // For now, return an error indicating GPU PCA is not fully implemented
109        Err(TransformError::NotImplemented(
110            "GPU-accelerated PCA is not yet fully implemented. Use CPU PCA instead.".to_string(),
111        ))
112    }
113
114    /// Transform data using the fitted PCA model on GPU
115    ///
116    /// Currently this is a placeholder implementation that will return an error
117    /// indicating that full GPU PCA support is not yet implemented.
118    ///
119    /// # Arguments
120    ///
121    /// * `x` - Input data matrix with shape (n_samples, n_features)
122    ///
123    /// # Returns
124    ///
125    /// Transformed data matrix with shape (n_samples, n_components)
126    ///
127    /// # Errors
128    ///
129    /// Returns an error indicating that GPU PCA is not fully implemented yet
130    pub fn transform(&self, x: &ArrayView2<f64>) -> Result<Array2<f64>> {
131        check_not_empty(x, "x")?;
132        checkarray_finite(x, "x")?;
133
134        Err(TransformError::NotImplemented(
135            "GPU-accelerated PCA transform is not yet fully implemented. Use CPU PCA instead."
136                .to_string(),
137        ))
138    }
139
140    /// Fit the PCA model and transform data in one step
141    ///
142    /// Currently this is a placeholder implementation that will return an error
143    /// indicating that full GPU PCA support is not yet implemented.
144    ///
145    /// # Arguments
146    ///
147    /// * `x` - Input data matrix with shape (n_samples, n_features)
148    ///
149    /// # Returns
150    ///
151    /// Transformed data matrix with shape (n_samples, n_components)
152    ///
153    /// # Errors
154    ///
155    /// Returns an error indicating that GPU PCA is not fully implemented yet
156    pub fn fit_transform(&mut self, x: &ArrayView2<f64>) -> Result<Array2<f64>> {
157        self.fit(x)?;
158        self.transform(x)
159    }
160
161    /// Get the explained variance ratio for each principal component
162    ///
163    /// # Returns
164    ///
165    /// Array of explained variance ratios with length n_components
166    ///
167    /// # Errors
168    ///
169    /// Returns an error if the model has not been fitted
170    pub fn explained_variance_ratio(&self) -> Result<Array1<f64>> {
171        let explained_var = self
172            .explained_variance
173            .as_ref()
174            .ok_or_else(|| TransformError::NotFitted("PCA model not fitted".to_string()))?;
175
176        let total_var = explained_var.sum();
177        Ok(explained_var / total_var)
178    }
179}
180
181/// GPU-accelerated matrix operations for transformations
182#[cfg(feature = "gpu")]
183pub struct GpuMatrixOps {
184    #[allow(dead_code)]
185    gpu_context: GpuContext,
186}
187
188#[cfg(feature = "gpu")]
189impl GpuMatrixOps {
190    /// Create new GPU matrix operations instance
191    pub fn new() -> Result<Self> {
192        let gpu_context = GpuContext::new(GpuBackend::preferred()).map_err(|e| {
193            TransformError::ComputationError(format!("Failed to initialize GPU: {}", e))
194        })?;
195
196        Ok(GpuMatrixOps { gpu_context })
197    }
198
199    /// GPU-accelerated matrix multiplication (placeholder)
200    pub fn matmul(self_a: &ArrayView2<f64>, b: &ArrayView2<f64>) -> Result<Array2<f64>> {
201        Err(TransformError::NotImplemented(
202            "GPU matrix multiplication is not yet implemented. Use CPU operations instead."
203                .to_string(),
204        ))
205    }
206
207    /// GPU-accelerated SVD decomposition (placeholder)
208    pub fn svd(selfa: &ArrayView2<f64>) -> Result<(Array2<f64>, Array1<f64>, Array2<f64>)> {
209        Err(TransformError::NotImplemented(
210            "GPU SVD is not yet implemented. Use CPU operations instead.".to_string(),
211        ))
212    }
213
214    /// GPU-accelerated eigendecomposition (placeholder)
215    pub fn eigh(selfa: &ArrayView2<f64>) -> Result<(Array1<f64>, Array2<f64>)> {
216        Err(TransformError::NotImplemented(
217            "GPU eigendecomposition is not yet implemented. Use CPU operations instead."
218                .to_string(),
219        ))
220    }
221}
222
223/// GPU-accelerated t-SNE implementation
224#[cfg(feature = "gpu")]
225pub struct GpuTSNE {
226    /// Number of dimensions for the embedding
227    pub n_components: usize,
228    /// Perplexity parameter
229    pub perplexity: f64,
230    /// Learning rate
231    pub learning_rate: f64,
232    /// Maximum number of iterations
233    pub max_iter: usize,
234    /// GPU context
235    #[allow(dead_code)]
236    gpu_context: GpuContext,
237}
238
239#[cfg(feature = "gpu")]
240impl GpuTSNE {
241    /// Create new GPU t-SNE instance
242    pub fn new(n_components: usize) -> Result<Self> {
243        check_positive(n_components, "n_components")?;
244
245        let gpu_context = GpuContext::new(GpuBackend::preferred()).map_err(|e| {
246            TransformError::ComputationError(format!("Failed to initialize GPU: {}", e))
247        })?;
248
249        Ok(GpuTSNE {
250            n_components,
251            perplexity: 30.0,
252            learning_rate: 200.0,
253            max_iter: 1000,
254            gpu_context,
255        })
256    }
257
258    /// Set perplexity parameter
259    pub fn with_perplexity(mut self, perplexity: f64) -> Self {
260        self.perplexity = perplexity;
261        self
262    }
263
264    /// Set learning rate
265    pub fn with_learning_rate(mut self, learning_rate: f64) -> Self {
266        self.learning_rate = learning_rate;
267        self
268    }
269
270    /// Set maximum iterations
271    pub fn with_max_iter(mut self, max_iter: usize) -> Self {
272        self.max_iter = max_iter;
273        self
274    }
275
276    /// Fit and transform data using GPU-accelerated t-SNE (placeholder)
277    pub fn fit_transform(selfx: &ArrayView2<f64>) -> Result<Array2<f64>> {
278        Err(TransformError::NotImplemented(
279            "GPU t-SNE is not yet implemented. Use CPU t-SNE instead.".to_string(),
280        ))
281    }
282}
283
284// Stub implementations when GPU feature is not enabled
285#[cfg(not(feature = "gpu"))]
286pub struct GpuPCA;
287
288#[cfg(not(feature = "gpu"))]
289pub struct GpuMatrixOps;
290
291#[cfg(not(feature = "gpu"))]
292pub struct GpuTSNE;
293
294#[cfg(not(feature = "gpu"))]
295impl GpuPCA {
296    pub fn new(_ncomponents: usize) -> Result<Self> {
297        Err(TransformError::FeatureNotEnabled(
298            "GPU acceleration requires the 'gpu' feature to be enabled".to_string(),
299        ))
300    }
301}
302
303#[cfg(not(feature = "gpu"))]
304impl GpuMatrixOps {
305    pub fn new() -> Result<Self> {
306        Err(TransformError::FeatureNotEnabled(
307            "GPU acceleration requires the 'gpu' feature to be enabled".to_string(),
308        ))
309    }
310}
311
312#[cfg(not(feature = "gpu"))]
313impl GpuTSNE {
314    pub fn new(_ncomponents: usize) -> Result<Self> {
315        Err(TransformError::FeatureNotEnabled(
316            "GPU acceleration requires the 'gpu' feature to be enabled".to_string(),
317        ))
318    }
319}
320
321#[cfg(test)]
322mod tests {
323    use super::*;
324
325    #[test]
326    #[cfg(feature = "gpu")]
327    fn test_gpu_pca_creation() {
328        let pca = GpuPCA::new(3);
329        assert!(pca.is_ok());
330        let pca = pca.expect("Operation failed");
331        assert_eq!(pca.n_components, 3);
332        assert!(pca.center);
333        assert!(pca.components.is_none());
334        assert!(pca.explained_variance.is_none());
335        assert!(pca.mean.is_none());
336    }
337
338    #[test]
339    #[cfg(feature = "gpu")]
340    fn test_gpu_pca_invalid_components() {
341        let result = GpuPCA::new(0);
342        assert!(result.is_err());
343    }
344
345    #[test]
346    #[cfg(feature = "gpu")]
347    fn test_gpu_matrix_ops_creation() {
348        let ops = GpuMatrixOps::new();
349        assert!(ops.is_ok());
350    }
351
352    #[test]
353    #[cfg(feature = "gpu")]
354    fn test_gpu_tsne_creation() {
355        let tsne = GpuTSNE::new(2);
356        assert!(tsne.is_ok());
357        let tsne = tsne.expect("Operation failed");
358        assert_eq!(tsne.n_components, 2);
359        assert_eq!(tsne.perplexity, 30.0);
360        assert_eq!(tsne.learning_rate, 200.0);
361        assert_eq!(tsne.max_iter, 1000);
362    }
363
364    #[test]
365    #[cfg(feature = "gpu")]
366    fn test_gpu_tsne_with_params() {
367        let tsne = GpuTSNE::new(3)
368            .expect("Operation failed")
369            .with_perplexity(50.0)
370            .with_learning_rate(100.0)
371            .with_max_iter(500);
372
373        assert_eq!(tsne.n_components, 3);
374        assert_eq!(tsne.perplexity, 50.0);
375        assert_eq!(tsne.learning_rate, 100.0);
376        assert_eq!(tsne.max_iter, 500);
377    }
378
379    #[test]
380    #[cfg(not(feature = "gpu"))]
381    fn test_gpu_features_disabled() {
382        assert!(GpuPCA::new(2).is_err());
383        assert!(GpuMatrixOps::new().is_err());
384        assert!(GpuTSNE::new(2).is_err());
385    }
386}
scirs2_transform/gpu.rs

scirs2_transform/
gpu.rs
