SPSS Statistics

SPSS Statistics

Your hub for statistical analysis, data management, and data documentation. Connect, learn, and share with your peers! 

 View Only
  • 1.  The relationship between the component matrix and component plot in PCA output

    Posted Thu July 27, 2023 03:57 PM
    Edited by Alice Fujiwara Thu July 27, 2023 07:57 PM

    When conducting principal component analysis (PCA) using SPSS, we can obtain both the component matrix and the component plot in the output. Are these two the same thing? In other words, are the values of the plotted points in the component plot equal to the numerical values in the component matrix?

    I find the component plot very intuitive, so I would like to recreate it for use in my research paper. Therefore, I want to understand where the data in this plot comes from.


    ------------------------------
    Alice Fujiwara
    ------------------------------



  • 2.  RE: The relationship between the component matrix and component plot in PCA output

    Posted Thu July 27, 2023 05:03 PM
    Edited by Kirill Orlov Thu July 27, 2023 05:10 PM

    If by component plot you mean the loading plot, then yes, the loading plot is the scatterplot of the loadings taken from the component loading matrix.



    ------------------------------
    Kirill Orlov
    ------------------------------



  • 3.  RE: The relationship between the component matrix and component plot in PCA output

    Posted Thu July 27, 2023 08:07 PM
    Edited by Alice Fujiwara Thu July 27, 2023 08:17 PM

    Thank you!

    But sorry, I am not sure what loading plot is.

    I got component matrix and the component plot in the output of PCA (see figures attached).

    I find the component plot very intuitive. However, I feel that the original figure may not be suitable for publishing. So I would like to recreate it for use in my paper. Therefore, I want to understand where the data in this plot comes from.


    ------------------------------
    Alice Fujiwara
    ------------------------------



  • 4.  RE: The relationship between the component matrix and component plot in PCA output

    Posted Thu July 27, 2023 09:30 PM

    Principal Component Analysis (PCA) in SPSS provides two outputs: the component matrix and the component plot.

    1. Component Matrix: It shows the correlation coefficients between original variables and principal components. High values indicate strong correlations.

    2. Component Plot: It represents observations projected onto principal components in a lower-dimensional space. Data points' positions come from scores calculated using loadings from the component matrix.

    To recreate the component plot, extract scores from PCA results and plot data points in a scatter plot or 3D plot, providing an intuitive visualization of data structure and patterns.



    ------------------------------
    Youssef Sbai Idrissi
    Software Engineer
    ------------------------------



  • 5.  RE: The relationship between the component matrix and component plot in PCA output

    Posted Fri July 28, 2023 02:37 AM

    Thank you very much!



    ------------------------------
    Alice Fujiwara
    ------------------------------



  • 6.  RE: The relationship between the component matrix and component plot in PCA output

    Posted Thu July 27, 2023 10:38 PM

    The component matrix is the loading matrix and the component plot is the loading plot. They give the same numbers.

    You can manually edit the plot (for example, rotate it as you like, add spike projections, etc.) You may also copy-paste the matrix to a dataset and build a  scatterplot yourself.



    ------------------------------
    Kirill Orlov
    ------------------------------



  • 7.  RE: The relationship between the component matrix and component plot in PCA output

    Posted Fri July 28, 2023 02:37 AM

    Thank you very much!



    ------------------------------
    Alice Fujiwara
    ------------------------------



  • 8.  RE: The relationship between the component matrix and component plot in PCA output

    Posted Fri July 28, 2023 09:10 AM
    Rather than copy-paste, use OMS to capture the table as an SPSS dataset.  See Utilities > OMS Control Panel for details on OMS.

    Also, you might find that a scatterplot matrix makes a better plot for these data.

    --