Simple convex optimization problem fails in CVX

[mermeladeK]

I am using the CVX tool from Boyd for convex optimization.

I need to implement the convex function [latex]\frac{1}{xy}[/latex] for positive numbers.

 

I figured one way which is the same method used when convexifying a Geommetric Program. However for some reason it fails to do a simple case. The code in matlab is:

 

cvx_begin

variables p q r

minimize( r )

p<=log(2)

q<=log(3)

0<=p+q+r

cvx_end

 

[latex]\exp{r}[/latex] is [latex]\frac{1}{2*3}[/latex]. However it fails and says

 

??? Index exceeds matrix dimensions.

 

Error in ==> cvxprob.eliminate at 215

temp = reshape(ndxs(temp),size(temp));

 

Error in ==> cvxprob.solve at 14

[ At, cones, sgn, Q, P, dualized ] = eliminate( prob, true );

 

Error in ==> cvx_end at 77

solve( prob );

Edited August 2, 2011 by mermeladeK