The features of my dataset are like below:
• BI-RADS assessment: 1 to 5 (ordinal)
• Age: patient's age in years (integer) ranges from 18 to 96
• Shape: mass shape: round=1 oval=2 lobular=3 irregular=4 (nominal)
• Margin: mass margin: circumscribed=1 microlobulated=2 obscured=3 ill-defined=4 spiculated=5 (nominal)
• Density: mass density high=1 iso=2 low=3 fat-containing=4 (ordinal)
When I run
"strain" criterion on such a dataset without normalizing it first, I get a result as follows:
However, if I normalize the data the result is as follows:
The second results is pretty similar to results that I have got for other criteria and also for the
PCA even I didn't normalize the data for them also.
So, my question is: Why does normalizing data make difference for "strain" criterion?
Thanks in advance...