# Question mark on Correlation Matrix with RapidMiner

I'm using RapidMiner to evaluate correlation between attribute in my dataset. The problem is that a lot of values appear with '?'.

Someone can help me?

This is a sample of data

• I don't know the software, but it's likely that it fails to compute the correlation. That can be due to incomplete rows in the dataset, non-numeric data, zero division (in case of null variance, but that's not likely, given the number of cases), or something else. Can you share a sample of your data? – Romain Reboulleau Nov 20 '19 at 18:53
• Yeah, I've edited the post. – Lorenzoi Nov 20 '19 at 21:27

All your data is non-numeric, so there is no straightforward method to compute a correlation value. It appears that the software does compute a correlation value between 2-valued fields (breast and irradiat).
• Give numeric values to ordered categories. For instance, for the age field, you could certainly use a centered numeric value for each category (45 instead of 40-49, 55 instead of 50-59, etc.), or just a rank.