# (SOLVED) Wrong Correlation Matrix Output

Hello,

i just started working with rapidminer and have a problem using a correlation matrix:

My database is an excel sheet. The feed into Rapidminer works, however when i connect a correlation matrix operator next to it, the results in the matrix show many "?" instead of values between -1 and 1. Single cells show actual values, however some of them are outside of the normal -1 to What does this mean? I have 15 attributes, is that to much?!

Thank you very much in advance

i just started working with rapidminer and have a problem using a correlation matrix:

My database is an excel sheet. The feed into Rapidminer works, however when i connect a correlation matrix operator next to it, the results in the matrix show many "?" instead of values between -1 and 1. Single cells show actual values, however some of them are outside of the normal -1 to What does this mean? I have 15 attributes, is that to much?!

Thank you very much in advance

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## Answers

1,869Unicorn15 attributes are definitely not too much. There is either a problem with the process setup, with the data or maybe there is a bug in the Correlation Matrix operator. Can you please post the XML of your process?

It would also be good if you could provide a sample of your data.

Best regards,

Marius

8Contributor IThe used Database consisted of many constant values for most of the attributes. The "Correlation Matrix"-Operator uses the Pearson Correlation Coefficient. As the standard deviation of this formula is listed in the denominator, the correlation is not defined for constant values. This was the reason for the "?" Output in many of the correlation matrix cells.

Big thanks to Marius for his great support!

1Newbie2,959Community ManagerScott