https://communities.sas.com/t5/Statistical-Procedures/raising-matrix-to-negative-power/m-p/58117#M2714 Your problem is not SAS.<BR /> <BR /> Your problem is that a negative number raised to a fractional power is simply not defined in the domain of real numbers.<BR /> <BR /> Example: Square root of –2 cannot be computed in the domain of real numbers.<BR /> <BR /> You need to define exactly what it is you want, and perhaps come up with a better understanding/explanation of why/how you need to raise a negative number to a fractional power. Fri, 24 Jul 2009 17:00:27 GMT Paige 2009-07-24T17:00:27Z https://communities.sas.com/t5/Statistical-Procedures/raising-matrix-to-negative-power/m-p/58116#M2713 I have a critical problem.I need to raise a matrix to certain power using (##)operator,the problem is that the power is negative fraction and some elements of the matrix are negative fraction also.the program returuns an error message each time I run it and confirms that the operation couldnot be performed.I donot know how to solve this problem.please I ask for help<BR /> Best Regards,<BR /> Amani Thu, 23 Jul 2009 20:45:11 GMT https://communities.sas.com/t5/Statistical-Procedures/raising-matrix-to-negative-power/m-p/58116#M2713 deleted_user 2009-07-23T20:45:11Z https://communities.sas.com/t5/Statistical-Procedures/raising-matrix-to-negative-power/m-p/58117#M2714 Your problem is not SAS.<BR /> <BR /> Your problem is that a negative number raised to a fractional power is simply not defined in the domain of real numbers.<BR /> <BR /> Example: Square root of –2 cannot be computed in the domain of real numbers.<BR /> <BR /> You need to define exactly what it is you want, and perhaps come up with a better understanding/explanation of why/how you need to raise a negative number to a fractional power. Fri, 24 Jul 2009 17:00:27 GMT https://communities.sas.com/t5/Statistical-Procedures/raising-matrix-to-negative-power/m-p/58117#M2714 Paige 2009-07-24T17:00:27Z