Mat.inv() yielding all zeroes in opencv

edit

I have the following code :

    cv::Mat temp0 = R.t();
    cv::Mat temp1 = R * temp0;
    cv::Mat temp2(960, 960, CV_32FC1);
    temp2 = temp1.inv();

    cv::Size s = temp1.size();
    std::cout<<s.height<<" "<<s.width<<std::endl;

    std::cout<<cv::format(temp1, "numpy" ) << std::endl;
    std::cout<<cv::format(temp2, "numpy" ) << std::endl;

The Transpose works correctly, so does the matrix multiplication. Thus the Mat temp1 has a size of 960x960. However, when I do temp2 =temp1.inv(), I recieve all zeroes in temp2. I mean zeroes is all of the 960x960 cells. Also, R is of type CV_32FC1 only. So it is probably not a datatype issue. I cannot understand the issue here. I googled so much. Can you please help.

EDIT

I am copying below the gdb output for the Mat::inv() function. I am having a hard time figuring it all out, but if someone is more familiar with opencv, maybe it will be of help :)

Breakpoint 1, CreateShares::ConstructShares (this=0x80556d0, channel=..., k=2, n=4) at CreateShares.cpp:165
165     temp2 = temp1.inv();
(gdb) step

cv::Mat::operator= (this=0xbffff294, e=...) at /usr/include/opencv2/core/mat.hpp:1373
1373        e.op->assign(e, *this);
(gdb) 
1374        return *this;
(gdb) step
1375    }    
(gdb) step
cv::MatExpr::~MatExpr (this=0xbfffef64, __in_chrg=<optimized out>) at /usr/include/opencv2/core/mat.hpp:1167
1167    class CV_EXPORTS MatExpr
(gdb) step
cv::Mat::~Mat (this=0xbfffefdc, __in_chrg=<optimized out>) at /usr/include/opencv2/core/mat.hpp:295
295     release();
(gdb) step
cv::Mat::release (this=0xbfffefdc) at /usr/include/opencv2/core/mat.hpp:381
381     if( refcount && CV_XADD(refcount, -1) == 1 )
(gdb) step
383     data = datastart = dataend = datalimit = 0;
(gdb) step
384     size.p[0] = 0;
(gdb) step
385     refcount = 0;
(gdb) step
386 }
(gdb) step
cv::Mat::~Mat (this=0xbfffefdc, __in_chrg=<optimized out>) at /usr/include/opencv2/core/mat.hpp:296
296     if( step.p != step.buf )
(gdb) step
298 }
(gdb) step
cv::Mat::~Mat (this=0xbfffefa4, __in_chrg=<optimized out>) at /usr/include/opencv2/core/mat.hpp:295
295     release();
(gdb) step
cv::Mat::release (this=0xbfffefa4) at /usr/include/opencv2/core/mat.hpp:381
381     if( refcount && CV_XADD(refcount, -1) == 1 )
(gdb) step
383     data = datastart = dataend = datalimit = 0;
(gdb) step
384     size.p[0] = 0;
(gdb) step
385     refcount = 0;
(gdb) step
386 }
(gdb) step
cv::Mat::~Mat (this=0xbfffefa4, __in_chrg=<optimized out>) at /usr/include/opencv2/core/mat.hpp:296
296     if( step.p != step.buf )
(gdb) step
298 }
(gdb) step
cv::Mat::~Mat (this=0xbfffef6c, __in_chrg=<optimized out>) at /usr/include/opencv2/core/mat.hpp:295
295     release();
(gdb) step
cv::Mat::release (this=0xbfffef6c) at /usr/include/opencv2/core/mat.hpp:381
381     if( refcount && CV_XADD(refcount, -1) == 1 )
(gdb) step
383     data = datastart = dataend = datalimit = 0;
(gdb) step
384     size.p[0] = 0;
(gdb) step
385     refcount = 0;
(gdb) step
386 }
(gdb) step
cv::Mat::~Mat (this=0xbfffef6c, __in_chrg=<optimized out>) at /usr/include/opencv2/core/mat.hpp:296
296     if( step.p ...