Blunt and Pointed Cones
According to the above definition, if C is a convex cone, then C{0} is a convex cone, too. A convex cone is said to be pointed or blunt depending on whether it includes the null vector 0 or not. Blunt cones can be excluded from the definition of convex cone by substituting "non-negative" for "positive" in the condition of α, β. The term "pointed" is also often used to refer to a closed cone that contains no complete line (i.e., no nontrivial subspace of the ambient vector space V), i.e. what is called a "salient" cone below.
Read more about this topic: Convex Cone
Famous quotes containing the words blunt, pointed and/or cones:
“Give me the keys. I feel for the common chord again,
Sliding by semi-tones till I sink to a minor,—yes,
And I blunt it into a ninth, and I stand on alien ground,
Surveying a while the heights I rolled from into the deep;
Which, hark, I have dared and done, for my resting-place is found,
The C Major of this life: so, now I will try to sleep.”
—Robert Browning (1812–1889)
““Courage!” he said, and pointed toward the land,
“This mounting wave will roll us shoreward soon.”
In the afternoon they came unto a land
In which it seemed always afternoon.”
—Alfred Tennyson (1809–1892)
“Here was a little of everything in a small compass to satisfy the wants and the ambition of the woods,... but there seemed to me, as usual, a preponderance of children’s toys,—dogs to bark, and cats to mew, and trumpets to blow, where natives there hardly are yet. As if a child born into the Maine woods, among the pine cones and cedar berries, could not do without such a sugar-man or skipping-jack as the young Rothschild has.”
—Henry David Thoreau (1817–1862)