<p>It depends what is meant by &quot;features&quot;. Features can be a particular structure component in the RNA structure. In ML/DL these &quot;features&quot; are called instances (or observations). &quot;Features&quot; is also a technical word used in machine/deep learning, which can be completely different, it means the data or statistical variables associated with an instance.</p>
<p>Feature weight extraction (ML/DL definition) using unsupervised learning is complicated, but doable. This is where the features corresponding to each entry are weighted, i.e. quantified. Under traditional unsupervised learning this is not achievable, unless you want to include/exclude &quot;features&quot; and assess cluster integrity. I personally considered it a lot of work for no real interpretable results.</p>
<p>If the features are components of the RNA structure (what would be technically called 'instances' in ML/DL) then the general traditional unsupervised learning following PCA analysis is tSNE. However, tSNE is often used to get better resolution the PCA feature reduction output, i.e. tightens the clusters. PCA-&gt;tSNE is a cool technique and works well. PCA and tSNE can give different clusters by the way. As a rule of thumb I consider PCA &gt; tSNE.</p>
<p>Multi-dimensional scaling etc ... needs a defined analytics aim.</p>
<hr />
<p>Information on tSNE and PCA this online resource looks fine</p>
<p><a href="https://www.datacamp.com/tutorial/introduction-t-sne" rel="nofollow noreferrer">https://www.datacamp.com/tutorial/introduction-t-sne</a></p>
<p>The above is if you want to do tSNE and compare the results to PCA this link is good.</p>
<p>In terms of using tSNE to sharpen PCA clusters I always used O'Reilly's &quot;Introduction to Machine Learning with Python&quot;. There is a very clear example of Python code of the technique there, towards the end of the book and why it works.</p>

CC BY-SA 4.0
2023-08-09T14:45:44.107Z
Thanks! Do you have any resources I could look into that would help me understand how to frame this as a PCA problem as someone new to it? If not no worries
joshua213p
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2023-08-09T15:05:30.287Z
Makes sense re: edit, thank you!
joshua213p
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2023-08-09T15:06:01.347Z
Dear @joshua213p I have answered below the `--------`
M__
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2023-08-09T16:04:52.153Z
Thanks @joshua213p
M__
CC BY-SA 4.0
2023-08-09T21:35:11.210Z
hey! reading through the t-sne blogpost and I'm a little unclear on how i'd use either of these algorithms here for my goals. i get it'd cluster my samples based on similarity in terms of first and second principal components/t-SNEs, but what could i then use identify structural or sequence patterns within each cluster? please let me know if I'm missing something - thanks!
joshua213p
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2023-08-09T21:45:09.403Z
Hi @joshua213p can you submit this as a separate question please?
M__
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2023-08-09T13:30:34.170Z
2023-08-09T15:12:53.113Z
2023-08-09T15:12:53.113Z
M__
<p>I have a bunch of RNA sequences (and their optimal secondary structures) and their corresponding energy values (measured by mean free energy) and I'm trying to find a way to identify features (patterns in their structures or sequences) common between samples of similar energy values. the overall goal is to try and identify sequence or structural elements in the RNA samples that tend to correlate with low mean free energy values. would be grateful if anyone could recommend me algorithms to look into using - I'm assuming this would be an unsupervised learning project and I only have experience with supervised stuff, but I'm looking into PCA right now and not sure if that'd be useful. should I be looking into something else?</p>
<p>Intuitively I'm imagining it as like a clustering + feature extraction problem where I have a bunch of dots, each representing an RNA sample, and then the axis represents energy so the dots could be clustered in energy value similarity and then within each energy value cluster patterns/relationships could be found between the sequences and structures of the samples. but not sure if an ML algo exists to handle this and PCA seems like not what I'm looking for because the axes would be principal components and not energy...</p>

<rna><clustering><features><unsupervised-learning>
Help with finding an unsupervised learning algorithm for RNA sequence/structure pattern identification
# Help with finding an unsupervised learning algorithm for RNA sequence/structure pattern identification

(Asked by: username_0 on 2023-08-09)

I have a bunch of RNA sequences (and their optimal secondary structures) and their corresponding energy values (measured by mean free energy) and I'm trying to find a way to identify features (patterns in their structures or sequences) common between samples of similar energy values. the overall goal is to try and identify sequence or structural elements in the RNA samples that tend to correlate with low mean free energy values. would be grateful if anyone could recommend me algorithms to look into using - I'm assuming this would be an unsupervised learning project and I only have experience with supervised stuff, but I'm looking into PCA right now and not sure if that'd be useful. should I be looking into something else?

Intuitively I'm imagining it as like a clustering + feature extraction problem where I have a bunch of dots, each representing an RNA sample, and then the axis represents energy so the dots could be clustered in energy value similarity and then within each energy value cluster patterns/relationships could be found between the sequences and structures of the samples. but not sure if an ML algo exists to handle this and PCA seems like not what I'm looking for because the axes would be principal components and not energy...

**Tags:** rna, clustering, features, unsupervised-learning

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## 1 answers

### Answer by username_1 on 2023-08-09. Score: 0 | Accepted answer

It depends what is meant by "features". Features can be a particular structure component in the RNA structure. In ML/DL these "features" are called instances (or observations). "Features" is also a technical word used in machine/deep learning, which can be completely different, it means the data or statistical variables associated with an instance.

Feature weight extraction (ML/DL definition) using unsupervised learning is complicated, but doable. This is where the features corresponding to each entry are weighted, i.e. quantified. Under traditional unsupervised learning this is not achievable, unless you want to include/exclude "features" and assess cluster integrity. I personally considered it a lot of work for no real interpretable results.

If the features are components of the RNA structure (what would be technically called 'instances' in ML/DL) then the general traditional unsupervised learning following PCA analysis is tSNE. However, tSNE is often used to get better resolution the PCA feature reduction output, i.e. tightens the clusters. PCA->tSNE is a cool technique and works well. PCA and tSNE can give different clusters by the way. As a rule of thumb I consider PCA > tSNE.

Multi-dimensional scaling etc ... needs a defined analytics aim.

---

Information on tSNE and PCA this online resource looks fine

<https://www.datacamp.com/tutorial/introduction-t-sne>

The above is if you want to do tSNE and compare the results to PCA this link is good.

In terms of using tSNE to sharpen PCA clusters I always used O'Reilly's "Introduction to Machine Learning with Python". There is a very clear example of Python code of the technique there, towards the end of the book and why it works.

> **Comments:**
> **username_0**: Thanks! Do you have any resources I could look into that would help me understand how to frame this as a PCA problem as someone new to it? If not no worries  
> **username_0**: Makes sense re: edit, thank you!  
> **username_1**: Dear @joshua213p I have answered below the `--------`  
> **username_1**: Thanks @joshua213p  
> **username_0**: hey! reading through the t-sne blogpost and I'm a little unclear on how i'd use either of these algorithms here for my goals. i get it'd cluster my samples based on similarity in terms of first and second principal components/t-SNEs, but what could i then use identify structural or sequence patterns within each cluster? please let me know if I'm missing something - thanks!  
> **username_1**: Hi @joshua213p can you submit this as a separate question please?  

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