C. Auguste Dupin Dostoevsky called Poe "an enormously talented writer" and favorably reviewed Poe's detective stories. The character Porfiry Petrovich in Dostoevsky's novel "Crime and Punishment" was influenced by Dupin. In the first Sherlock Holmes story, "A Study in Scarlet" (1887), Doctor Watson compares Holmes to Dupin, to which Holmes replies: "No doubt you think you are complimenting me ... In my opinion, Dupin was a very inferior fellow... He had some analytical genius, no doubt; but he was by no means such a phenomenon as Poe appears to imagine". Alluding to an episode in "The Murders in the Rue Morgue", where Dupin
Dupin indicatrix Dupin indicatrix In differential geometry, the Dupin indicatrix is a method for characterising the local shape of a surface. Draw a plane parallel to the tangent plane and a small distance away from it. Consider the intersection of the surface with this plane. The shape of the intersection is related to the Gaussian curvature. The Dupin indicatrix is the result of the limiting process as the plane approaches the tangent plane. The indicatrix was invented by Charles Dupin. For elliptical points where the Gaussian curvature is positive the intersection will either be empty or form a closed curve. In the