TetGenLink

# San Francisco State University

# Solve the system of equalities and inequalities

down vote

Backsubstitution is an option often ignored when people use Reduce. In the op’s case it gives:

Reduce[a == b + c && a >= 2 && b <= 10 && c == 5, {a, b, c}, Backsubstitution -> True]

2 <= a <= 15 && b == -5 + a && c == 5

via equation solving – Solve the system of equalities and inequalities – Mathematica Stack Exchange

# torus is a surface having genus one

torus is a surface having genus one

# torus is a surface having genus one,

x = (c+acosv)cosu

(2)

y = (c+acosv)sinu

(3)

z = asinv

# Construct a graph from a weighted adjacency matrix:

WeightedAdjacencyGraph

# mathematica graphing a 2 by 2 matrix as an object

is there a possibility to “transform” a matrix (inheriting the input-output “weights”) into a graph object inheriting the matrix relations?

you can convert it to an edge-weighted graph using `WeightedAdjacencyGraph`

. This will give you a complete graph (a `Graph`

expression) in which each vertex is also connected *to itself*. I am not sure how much sense it makes treat this matrix as a graph, given the full connectivity.

Since you have a fully connected graph, it does not matter in your case, but be aware that `WeightedAdjacencyGraph`

represents missing edges with `Infinity`

, not with zero. This is somewhat annoying because it is inconsistent with `WeightedAdjacencyMatrix`

, which uses `0`

. While `Infinity`

does make sense in *some* (not all) applications, it is much more common to see data that uses 0.

via [✓] Convert matrix into “Graph object”? – Online Technical Discussion Groups—Wolfram Community

# Surface Intersection: New in Mathematica 10

Surface Intersection