How can I find the rows of a Eigen matrix are all the same, without resorting to looping? For instance:

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CNT2: (Rows: 8 Cols: 3)
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[[ 0.853553399021066, -0.146446592335918,  0.499999990612783]
 [ 0.853553407243179, -0.14644659683274,   0.499999975259668]
 [ 0.853553400883711, -0.146446603192209,  0.499999984253315]
 [ 0.853553411927206, -0.146446609232097,  0.499999963631846]
 [ 0.853553405380534, -0.146446585976449,  0.499999981619136]
 [ 0.853553409425403, -0.146446594650517,  0.499999972173537]
 [ 0.853553400883711, -0.146446603192209,  0.499999984253315]
 [ 0.853553403385515, -0.146446617773789,  0.499999975711622]]
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Of course that would take an epsilon about the first n figures (say six) after decimal point.
is there a way? Thank you