Exercise:PCA in 2D
From Ufldl
(→Step 1b: Check xRot) |
(→Step 1b: Check xRot) |
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[[File:pca_xrot_2d.png|360px]] | [[File:pca_xrot_2d.png|360px]] | ||
| - | Because Matlab/Octave could have returned <math>\textstyle -u_1</math> and/or <math>\textstyle -u_2</math> instead of <math>\textstyle u_1</math> and <math>\textstyle u_2</math>, it's also possible that you might have gotten a figure which is "flipped" or "reflected" along the <math>\textstyle x</math>- and/or <math>\textstyle y</math>-axis; this is also completely correct. | + | Because Matlab/Octave could have returned <math>\textstyle -u_1</math> and/or <math>\textstyle -u_2</math> instead of <math>\textstyle u_1</math> and <math>\textstyle u_2</math>, it's also possible that you might have gotten a figure which is "flipped" or "reflected" along the <math>\textstyle x</math>- and/or <math>\textstyle y</math>-axis; a flipped/reflected version of this figure is also a completely correct result. |
=== Step 2: Dimension reduce and replot === | === Step 2: Dimension reduce and replot === | ||
