access matrix value opencv

1On the documentation:
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3http://docs.opencv.org/2.4/modules/core/doc/basic_structures.html#mat
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5It says:
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7(...) if you know the matrix element type, e.g. it is float, then you can use at<>() method
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9That is, you can use:
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11Mat M(100, 100, CV_64F);
12cout << M.at<double>(0,0);
13Maybe it is easier to use the Mat_ class. It is a template wrapper for Mat. Mat_ has the operator() overloaded in order to access the elements.