--- /dev/null
+ScoreMatrix BLOSUM62Legacy
+#
+# The BLOSUM62 substitution matrix, as used in earlier versions of jalview
+#
+# Scores are not symbol case sensitive, unless column(s) are provided for lower case characters
+# The 'guide symbol' at the start of each row of score values is optional
+# Values may be integer or floating point, delimited by tab, space, comma or combinations
+#
+ A R N D C Q E G H I L K M F P S T W Y V B Z X *
+A 4 -1 -2 -2 0 -1 -1 0 -2 -1 -1 -1 -1 -2 -1 1 0 -3 -2 0 -2 -1 0 -4
+R -1 5 0 -2 -3 1 0 -2 0 -3 -2 2 -1 -3 -2 -1 -1 -3 -2 -3 -1 0 -1 -4
+N -2 0 6 1 -3 0 0 0 1 -3 -3 0 -2 -3 -2 1 0 -4 -2 -3 3 0 -1 -4
+D -2 -2 1 6 -3 0 2 -1 -1 -3 -4 -1 -3 -3 -1 0 -1 -4 -3 -3 4 1 -1 -4
+C 0 3 -3 -3 9 -3 -4 -3 -3 -1 -1 -3 -1 -2 -3 -1 -1 -2 -2 -1 -3 -3 -2 -4
+Q -1 1 0 0 -3 5 2 -2 0 -3 -2 1 0 -3 -1 0 -1 -2 -1 -2 0 3 -1 -4
+E -1 0 0 2 -4 2 5 -2 0 -3 -3 1 -2 -3 -1 0 -1 -3 -2 -2 1 4 -1 -4
+G 0 -2 0 -1 -3 -2 -2 6 -2 -4 -4 -2 -3 -3 -2 0 -2 -2 -3 -3 -1 -2 -1 -4
+H -2 0 1 -1 -3 0 0 -2 8 -3 -3 -1 -2 -1 -2 -1 -2 -2 2 -3 0 0 -1 -4
+I -1 -3 -3 -3 -1 -3 -3 -4 -3 4 2 -3 1 0 -3 -2 -1 -3 -1 3 -3 -3 -1 -4
+L -1 -2 -3 -4 -1 -2 -3 -4 -3 2 4 -2 2 0 -3 -2 -1 -2 -1 1 -4 -3 -1 -4
+K -1 2 0 -1 -3 1 1 -2 -1 -3 -2 5 -1 -3 -1 0 -1 -3 -2 -2 0 1 -1 -4
+M -1 -1 -2 -3 -1 0 -2 -3 -2 1 2 -1 5 0 -2 -1 -1 -1 -1 1 -3 -1 -1 -4
+F -2 -3 -3 -3 -2 -3 -3 -3 -1 0 0 -3 0 6 -4 -2 -2 1 3 -1 -3 -3 -1 -4
+P -1 -2 -2 -1 -3 -1 -1 -2 -2 -3 -3 -1 -2 -4 7 -1 -1 -4 -3 -2 -2 -1 -2 -4
+S 1 -1 1 0 -1 0 0 0 -1 -2 -2 0 -1 -2 -1 4 1 -3 -2 -2 0 0 0 -4
+T 0 -1 0 -1 -1 -1 -1 -2 -2 -1 -1 -1 -1 -2 -1 1 5 -2 -2 0 -1 -1 0 -4
+W -3 -3 -4 -4 -2 -2 -3 -2 -2 -3 -2 -3 -1 1 -4 -3 -2 11 2 -3 -4 -3 -2 -4
+Y -2 -2 -2 -3 -2 -1 -2 -3 2 -1 -1 -2 -1 3 -3 -2 -2 2 7 -1 -3 -2 -1 -4
+V 0 -3 -3 -3 -1 -2 -2 -3 -3 3 1 -2 1 -1 -2 -2 0 -3 -1 4 -3 -2 -1 -4
+B -2 -1 3 4 -3 0 1 -1 0 -3 -4 0 -3 -3 -2 0 -1 -4 -3 -3 4 1 -1 -4
+Z -1 0 0 1 -3 3 4 -2 0 -3 -3 1 -1 -3 -1 0 -1 -3 -2 -2 1 4 -1 -4
+X 0 -1 -1 -1 -2 -1 -1 -1 -1 -1 -1 -1 -1 -1 -2 0 0 -2 -1 -1 -1 -1 -1 -4
+* -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 1
<p>
<strong>Principal Component Analysis</strong>
</p>
- <p>A principal component analysis can be performed via the
- <a href="calculations.html">calculations dialog</a> which is accessed by selecting <strong>Calculate→Calculate
- Tree or PCA...</strong>.</p>
+ <p>
+ A principal component analysis can be performed via the <a
+ href="calculations.html">calculations dialog</a> which is accessed
+ by selecting <strong>Calculate→Calculate Tree or
+ PCA...</strong>.
+ </p>
<p>This calculation creates a spatial representation of the
similarities within a selected group, or all of the sequences in an
alignment. After the calculation finishes, a 3D viewer displays the
calculation are given in the <strong><em>Change
Parameters</em></strong> menu.
</p>
- <p>
- <em>PCA Calculation modes</em><br /> The default Jalview
- calculation mode (indicated when <em><strong>Jalview
- PCA Calculation</strong></em> is ticked in the <strong><em>Change
- Parameters</em></strong> menu) is to perform a PCA on a matrix where elements
- in the upper diagonal give the sum of scores for mutating in one
- direction, and the lower diagonal is the sum of scores for mutating
- in the other. For protein substitution models like BLOSUM62, this
- gives an asymmetric matrix, and a different PCA to a matrix produced
- with the method described in the paper by G. Casari, C. Sander and
- A. Valencia. Structural Biology volume 2, no. 2, February 1995 (<a
- href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7749921">pubmed</a>)
- and implemented at the SeqSpace server at the EBI. This method
- preconditions the matrix by multiplying it with its transpose, and
- can be employed in the PCA viewer by unchecking the <strong><em>Jalview
- PCA Calculation</em></strong> option in the <strong><em>Change
- Parameters</em></strong> menu.
- </p>
<img src="pcaviewer.gif">
<p>
<strong>The PCA Viewer</strong>
added to the Jalview desktop in v2.7.</em> <em>The Reset button
and Change Parameters menu were added in Jalview 2.8.</em> <em>Support
for PAM250 based PCA was added in Jalview 2.8.1.</em>
+ </p>
+ <p>
+ <strong>Reproducing PCA calculations performed with older
+ Jalview releases</strong> Jalview 2.10.2 included a revised PCA
+ implementation which treated Gaps and non-standard residues in the
+ same way as a matrix produced with the method described in the paper
+ by G. Casari, C. Sander and A. Valencia. Structural Biology volume
+ 2, no. 2, February 1995 (<a
+ href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7749921">pubmed</a>)
+ and implemented at the SeqSpace server at the EBI. To reproduce
+ calculations performed with earlier Jalview releases it is necessary
+ to execute the following Groovy script:
+
+ <pre>
+ jalview.analysis.scoremodels.ScoreMatrix.scoreGapAsAny=true
+ </pre>
+ Additionally, for PCAs performed with older versions of Jalview and
+ the Blosum62 matrix, it is also necessary to import the legacy
+ BLOSUM62 score matrix (which is asymmetric for mutations between C to
+ R) which can be downloaded at
+ http://www.jalview.org/examples/legacyBlosum62.scm
+ </p>
+
</body>
</html>