out[ ]array([ [- - ] ] ] ]]in [ ] out[ ]array([ ] ][- ] ]]in this casethe product yt would be expressed like soin [ ]np dot( tnp dot(xy)out[ ]array([ ]]to aid in writing code with lot of matrix operationsnumpy has matrix class which has modified indexing behavior to make it more matlab-likesingle rows and columns come back two-dimensional and multiplication with is matrix multiplication the above operation with numpy matrix would look likein [ ]xm np matrix(xin [ ]ym xm[: in [ ]xm out[ ]matrix([ [- - ] ] ] ]]in [ ]ym out[ ]matrix([ ] ][- ] ]]in [ ]ym xm ym out[ ]matrix([ ]]matrix also has special attribute which returns the matrix inversein [ ]xm out[ ]matrix([ - - - ] ] ] ]] advanced numpy www it-ebooks info