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I have these mean centered points:

X = [-0.7142;-1.7142;-1.7142;-0.7142;1.2857;1.2857;2.2857];
Y = [1.2857;0.2857;-0.7142;0.2857;0.2857;-0.7142;-0.7142];


I then calculated the PCA projection points as:

X_proj = [-2.2316; 0.0648; 1.044; -0.2725; -2.1535; 1.7647; 1.2005];
Y_proj = [2.8746; 3.4734; 1.5356; 1.5142; -2.4040; -1.4030; -2.3826];


with the modified axis given as:

y1 = 0.2053*x1 + 0;
y2 = -0.48719*x2 + 0;


I then did a plot in Matlab showing both the mean centered values, and then the projected values:

Where the red triangles represent the mean centeredprojected data and the blue squares represent the projectedmean centered data.

I find this a little graphically confusing.

Is it true that the projection points should show perpendicular "projection lines" to the dashed axes? How should this be shown better graphically?

I have these mean centered points:

X = [-0.7142;-1.7142;-1.7142;-0.7142;1.2857;1.2857;2.2857];
Y = [1.2857;0.2857;-0.7142;0.2857;0.2857;-0.7142;-0.7142];


I then calculated the PCA projection points as:

X_proj = [-2.2316; 0.0648; 1.044; -0.2725; -2.1535; 1.7647; 1.2005];
Y_proj = [2.8746; 3.4734; 1.5356; 1.5142; -2.4040; -1.4030; -2.3826];


with the modified axis given as:

y1 = 0.2053*x1 + 0;
y2 = -0.48719*x2 + 0;


I then did a plot in Matlab showing both the mean centered values, and then the projected values:

Where the red triangles represent the mean centered data and the blue squares represent the projected data.

I find this a little graphically confusing.

Is it true that the projection points should show perpendicular "projection lines" to the dashed axes? How should this be shown better graphically?

I have these mean centered points:

X = [-0.7142;-1.7142;-1.7142;-0.7142;1.2857;1.2857;2.2857];
Y = [1.2857;0.2857;-0.7142;0.2857;0.2857;-0.7142;-0.7142];


I then calculated the PCA projection points as:

X_proj = [-2.2316; 0.0648; 1.044; -0.2725; -2.1535; 1.7647; 1.2005];
Y_proj = [2.8746; 3.4734; 1.5356; 1.5142; -2.4040; -1.4030; -2.3826];


with the modified axis given as:

y1 = 0.2053*x1 + 0;
y2 = -0.48719*x2 + 0;


I then did a plot in Matlab showing both the mean centered values, and then the projected values:

Where the red triangles represent the projected data and the blue squares represent the mean centered data.

I find this a little graphically confusing.

Is it true that the projection points should show perpendicular "projection lines" to the dashed axes? How should this be shown better graphically?

1

Plot of PCA generated projection points

I have these mean centered points:

X = [-0.7142;-1.7142;-1.7142;-0.7142;1.2857;1.2857;2.2857];
Y = [1.2857;0.2857;-0.7142;0.2857;0.2857;-0.7142;-0.7142];


I then calculated the PCA projection points as:

X_proj = [-2.2316; 0.0648; 1.044; -0.2725; -2.1535; 1.7647; 1.2005];
Y_proj = [2.8746; 3.4734; 1.5356; 1.5142; -2.4040; -1.4030; -2.3826];


with the modified axis given as:

y1 = 0.2053*x1 + 0;
y2 = -0.48719*x2 + 0;


I then did a plot in Matlab showing both the mean centered values, and then the projected values:

Where the red triangles represent the mean centered data and the blue squares represent the projected data.

I find this a little graphically confusing.

Is it true that the projection points should show perpendicular "projection lines" to the dashed axes? How should this be shown better graphically?