http://www.victoria.ac.nz/psyc/paul-jose-files/modgraph/

This program also calculates simple slopes. My problem is that to calculate the simple slope I need to provide the covariation of variables and SPSS binary logistical regression doesn't calculate covariation. It does provide an estimation of correlation and I wonder if there is any way to calculate the covariation, or whether this is not possible/sensible using binary logistical regression?

Advice would be very much appreciated.

Thanks

Lisa