# Revision history [back]

### matrix with fractional number

m = matrix(R, 3, 3, lambda i, j: 1/(i + j) ); m

Sage tells me the following:

Traceback (click to the left of this block for traceback)

...

ZeroDivisionError: rational division by zero

why? it really confused me.

### matrix with fractional number

m = matrix(R, matrix(ZZ, 3, 3, lambda i, j: 1/(i + j) ); m

Sage tells me the following:

Traceback (click to the left of this block for traceback)

...

ZeroDivisionError: rational division by zero

why? it really confused me.