PCA Initialisation Error: ValueError: Cannot generate PCA initialization because input data, X, is an affinity matrix, not a samples x features matrix.

[Ebony-Watson]

When trying to run EMBEDR.fit() with DRA_params:{'initialization':'pca'}, this error is returned:

--------------------------------------------------------------------------- ValueError Traceback (most recent call last) Input In [23], in <cell line: 2>() 2 for alg,dat in DR_params: #for alg, param in DR_params: 3 # ## If we're doing t-SNE, then we use the perplexityparameter... 4 # if alg.lower() == 'tsne': (...) 11 12 ## Initialize a new object at each loop. 13 embObj = EMBEDR(DRA=alg, 14 perplexity=30, 15 n_jobs=n_jobs, (...) 22 project_name=f'{alg}_{dat}', 23 project_dir=project_dir) ---> 25 embObj.fit(input_datasets[dat]) ## Usefit` to generate the embeddings.
27 embObjs[(alg, dat)] = embObj

File ~\Miniconda3\envs\DRaim2\lib\site-packages\EMBEDR\embedr.py:280, in EMBEDR.fit(self, X)
277 self._validate_with_data(X)
279 ## Finally, we can do the computations!
--> 280 self._fit(null_fit=False)
282 #####################
283 ## Fit to the NULL ##
284 #####################
286 self._fit(null_fit=True)

File ~\Miniconda3\envs\DRaim2\lib\site-packages\EMBEDR\embedr.py:532, in EMBEDR._fit(self, null_fit)
530 ## We then need to get the requested embeddings.
531 if (self.DRA in ['tsne', 't-sne']):
--> 532 dY, dEES = self.get_tSNE_embedding(X=self.data_X,
533 kNN_graph=self.data_kNN,
534 aff_mat=self.data_P)
536 elif (self.DRA in ['umap']):
537 dY, dEES = self.get_UMAP_embedding(X=self.data_X,
538 kNN_graph=self.data_kNN,
539 aff_mat=self.data_P)

File ~\Miniconda3\envs\DRaim2\lib\site-packages\EMBEDR\embedr.py:1208, in EMBEDR.get_tSNE_embedding(self, X, kNN_graph, aff_mat, null_fit, return_tSNE_objects)
1198 seed_offset = n_embeds_made + ii
1200 embObj = tSNE_Embed(n_components=self.n_components,
1201 perplexity=self.perplexity,
1202 n_jobs=self.n_jobs,
1203 random_state=self._seed + seed_offset,
1204 verbose=self.verbose,
1205 **self.DRA_params)
-> 1208 embObj.fit(aff_mat)
1210 tmp_embed_arr[ii] = embObj.embedding[:]
1212 ## Calculate the EES

File ~\Miniconda3\envs\DRaim2\lib\site-packages\EMBEDR\tsne.py:200, in tSNE_Embed.fit(self, X, **aff_kwargs)
196 if self.verbose >= 1:
197 print(f"\nGenerating {self.n_components}-dimensional embedding"
198 f" with t-SNE!")
--> 200 P = self.initialize_embedding(X, **aff_kwargs)
202 ## Optimize Early Exaggeration Phase
203 try:

File ~\Miniconda3\envs\DRaim2\lib\site-packages\EMBEDR\tsne.py:327, in tSNE_Embed.initialize_embedding(self, X, **aff_kwargs)
325 err_str += f", X, is an affinity matrix, not a samples x"
326 err_str += f" features matrix."
--> 327 raise ValueError(err_str)
329 ## If we wanted a spectral initialization, do that here.
330 elif self.initialization == 'spectral':

ValueError: Cannot generate PCA initialization because input data, X, is an affinity matrix, not a samples x features matrix.`

I have been trying to work through the code, but I am unclear on why initialisation of the t-SNE embeddings swaps from taking the input data to only taking the affinity matrix, and therefore producing this error.

Please help!!