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0
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0answers
181 views

The geometry of functions $\mathbb{R}^2\rightarrow \mathbb{R}$ that satisfy the norm axioms

What are constraints on the "looks" of a function $f:\mathbb{R}^2\rightarrow \mathbb{R}$, if $f$ satisfies $$f(x_1+x_2)\leq f(x_1) + f(x_2), \ \quad x_1,x_2\in \mathbb{R}^2 \quad \quad (1)$$i.e. the ...
11
votes
2answers
588 views

What are all these “visualizations” of the 3-sphere?

a 2-sphere is a normal sphere. A 3-sphere is $$ x^2 + y^2 + z^2 + w^2 = 1 $$ My first question is, why isn't the w coordinate just time? I can plot a 4-d sphere in a symbolic math program and ...
0
votes
1answer
294 views

Visualizing solids of revolution

Can someone shed a little bit of light on the problem of volumes of revolution about the $x$-axis and the $y$-axis of the same shapes? Take for example $f(x)=x^2$. If we want to find the volume ...
8
votes
3answers
302 views

Three-dimensional art galleries

The well-known art gallery problem starts with an "art gallery" (a simple polygon in the plane, not necessarily convex) and asks for the minimum number of "guards" (points on the polygon) required to ...
4
votes
3answers
126 views

Visualizing identity $m\le3n-6$ for simple connected finite planar graphs

How can I visualize the identity $m\leq3n-6$ (where $m$ is the number of edges, $n$ the number of vertices) for simple connected finite planar graphs?
2
votes
2answers
143 views

Visualization of 4D Expanded form of $f(x,y) = y/x - x/y$

I have a (not so) simple question: how do I visualize the following: $$f(x,y,z) = ((yz)/x - x/(yz)) + (y/(xz) - (xz)/y) + (y/x - x/y)?$$ I am a csci person, but not a big math person, so I'm a bit ...
1
vote
1answer
495 views

Problem involving drawing a diagram with belts and elevators and specific directions on a given floor/belt

Today, while reading A Practical Guide to Problem Solving in Mathematics by Carol Meyer and Tom Sallee, I came across a problem I was unsure of how to solve except by brute forcing possibilities and ...
3
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2answers
193 views

Programs for visualizing math designed for laymen?

I'm looking for interactive applications that are for university topics (designed for windows) in mathematics only , preferably something that doesn't include programming languages to use because ...
3
votes
1answer
121 views

What's this type of chart called?

What's the name of this type of chart?
6
votes
1answer
229 views

Visualize operator algebras?

It seems to me that to study mathematics is to convert the abstract language into diagrams, graphs and images. It does depend on the subject how much this technique can ease the struggle yet most of ...
6
votes
3answers
338 views

Favourite proofs with a visualization

As a fan of 'visual' proofs, I love the book Visual Complex Analysis by Tristan Needham. For example, this picture http://en.wikipedia.org/wiki/File:Pythagoras_algebraic2.svg leads quickly to ...
5
votes
2answers
399 views

continuum between linear and logarithmic

A friend and I are working on a heatmap representing some population numbers. Initially we used a linear color scale by default. Then, because the numbers covered a wide range, I tried using a log ...
5
votes
2answers
184 views

linearly arranging the group tables of groups of order 128

I'm planning to make a video that shows color coded group tables for all 2328 groups of order 128 -- at 128$\times$128 pixels at 24 frames a second I think I get 97 seconds of video. Is there some ...
5
votes
1answer
290 views

Ways to visualize the real numbers?

I was just wondering if there are any diagrams for visualizing subsets of the real numbers, or totally 'radically' different ways of looking at them as a real line? The model of the line relies on ...
3
votes
1answer
108 views

Visualizing SPD cone for $3\times3$ matrices

Can anyone see a good way to visualize the SPD cone for 3x3 symmetric matrices? I'm interested in something that would highlight it's special structure, like non-smoothness. Here's one attempt, ...
1
vote
1answer
226 views

Visualize 3 parameters in a graph

How would one visualize 3 parameters, where 1 parameters depends on the other 2? I want to display the time on the y-axis which depends on the input value of two different types. I can only think of ...
2
votes
5answers
441 views

Software to display 3D surfaces

What are some examples of software or online services that can display surfaces that are defined implicitly (for example, the sphere $x^2 + y^2 + z^2 = 1$)? Please add an example of usage (if not ...
5
votes
1answer
340 views

Intuition about the size of $\aleph_k$ with $k>1$

Assuming CH for simplicity, I know of some more or less intuitive way to think about difference in sizes of $\aleph_0$ and $\aleph_1$. The most straightforward is the distinction of natural/rational ...
4
votes
8answers
2k views

Techniques for visualising $n$ dimension spaces

Can you guys point me to the types of things I should read about (I'm a maths lay person really) if I want to learn about the current thinking how $n$ dimensional spaces can be visualised and thus ...
1
vote
2answers
626 views

a visual route to learning Galois theory

I really like the ideas of Galois theory: that you can think about all the algebraic numbers you can make starting with some set of them that there is some structure to this set of "algebraically ...
0
votes
1answer
357 views

3D correlation visualization?

Incomer per person (x axis) correlates with life expectancy (y axis). These two indicators change over time (z axis). x correlates with y. Moreover, x and y both correlate with z. The question is: ...
3
votes
1answer
995 views

How to visualize the Gaussian curvature of a 3D surface?

I have a 3D surface. I want to visualize color-coded Gaussian Curvature. Is there any software (e.g. MATLAB, Mathematica) which can be used for calculating and visualizing the curvature in color code ...
4
votes
2answers
249 views

Computing the projection of an infinite 3D grid of points

Consider the subset $S$ of $\mathbb{R}^3$ consisting of points whose coordinates are integers (compare Gaussian integers, Euclid's orchard). The view from the origin has interesting structure; it has ...
13
votes
3answers
2k views

Cutting a Möbius strip down the middle

Why does the result of cutting a Möbius strip down the middle lengthwise have two full twists in it? I can account for one full twist--the identification of the top left corner with the bottom right ...
0
votes
2answers
191 views

Proof Visualization

I'm working through Apostol's 'Calculus, Vol 1', with a focus on learning the theory behind calculus. If you are not familiar, Apostol starts with analysis of the real line and works his way through ...
4
votes
1answer
138 views

Intuitive understanding a theorem in analysis

Is there a way to intuitively understand/visualize the following theorem in analysis? Let $(f_n)$ be a sequence of real functions differentiable in a finite/infinite open interval $(a,b)$. Suppose ...
4
votes
0answers
247 views

Visualizing the domain of the square root

I would like to show someone the domain of the complex square root function (the 2-sheeted riemann surface). Is there a good interactive visualization software for this? I would like some sort of ...
2
votes
1answer
223 views

general (asymmetric) real rank-2 tensor visualization in 3d

I have general rank-2 real tensor in 3d space represented as a 3x3 real matrix $M$ (it is gradient of a vector field). I am writing some code to visualize it in several isolated points, this is what I ...
14
votes
3answers
1k views

Interesting implicit surfaces in $\mathbb{R}^3$

I have just written a small program in C++ and OpenGl to plot implicit surfaces in $\mathbb{R}^3$ for a Graphical Computing class and now I'm in need of more interesting surfaces to implement! Some ...
7
votes
3answers
403 views

Reconciling 'intersecting planes' and 'linear transformation' interpretations of matrices

I've learned in linear algebra class that an $n \times m$ augmented matrix can be thought of as a collection of n planes in $\mathbb {R}^m$ . If the matrix is invertible, the planes all intersect at a ...
3
votes
3answers
478 views

Visualization of complex roots for quadratics

I read that if a parabola has no real roots, then its complex roots can be visualized by graphing the same parabola ($ax^2 + bx + c$) with $-a$ and then finding the roots of that, then using those ...
0
votes
1answer
273 views

Mathematical permutation drawing/visualization tool

I'm writing software and need to document an existing mathematical permutation in our code. I thought the folks here would know where I can find a drawing/visualization tool to draw a permutation ...
2
votes
2answers
652 views

calculate location on an isometric world map

I want to display a point with a latitude and a longitude value in an isometric world map using JavaScript and jQuery. For a rectangular map, I use the following code to calculate the x and y ...
2
votes
0answers
125 views

Turning real roots into curves (for visualisation)

One can obviously map a set of real numbers $x_1, x_2, \ldots x_N$ to a curve in 2-D via $y=(x-x_1)(x-x_2)\ldots(x-x_N)$. Thinking about data visualisation, one can portray a set of $N$ observations ...
5
votes
1answer
202 views

FLOSS tool to visualize 2- and 3-space matrix transformations

I'm looking for a FLOSS application (Windows or Ubuntu but preferably both) that can help me visualize matrix transformations in 2- and 3-space. So I'd like to be able to enter a vector or matrix, ...
8
votes
3answers
785 views

Is there a geometric interpretation of the exponential function of real numbers?

I can visualize the exponential function with the graph $y = e^x$, but I can do that for almost any function. In addition to its graph, the function $f(x) = x^n$ can be visualized as the volume of a ...
7
votes
1answer
123 views

Visualising a specific orbifold

Let $1 < k \in \mathbb N$ and $M = \{(z_1, z_2) \in \mathbb C^2 : k|z_1|^2 + |z_2|^2 = 1\}$. Let $S^1$ act on $M$ via $e^{i\theta}(z_1,z_2) = (e^{ik\theta} z_1, e^{i\theta} z_2)$. Then I am told ...
4
votes
3answers
480 views

Trying to draw the tautological line bundle ($\subseteq \mathbb{CP}^1\times \mathbb{C}^2$)

In order to learn about vector bundles, I would like to draw the tautological vector bundle over the complex projective line $$ E = \{(x,v) \in \mathbb{CP}^1 \times \mathbb{C}^2 : v \in x \} .$$ ...
5
votes
2answers
575 views

How to draw a complex line bundle?

The most basic example of a topologically non-trivial real line bundle is the well-known Möbius strip. Everyone who learns about vector bundles will be confronted by it, if only because it has the ...
0
votes
0answers
202 views

Visualization of 2-dimensional function spaces

As a follow-up question to what is the norm measuring in function spaces I just had an idea: How about visualizing function spaces as normal planes. What I have in mind is to have an orthogonal ...
7
votes
2answers
644 views

How to Visualize points on a high dimensional (>3) Manifold?

Are there any ways to visualize(plot/draw) points on a high dimensional (ex: dimension = 5) manifold?
9
votes
0answers
201 views

Visualizing the Partition numbers (suggestions for visualization techniques)

So Ken Ono says that the partition numbers behave like fractals, in which case I'd like to try to find an appropriately illuminating way of visualizing them. But I'm sort of stuck at the moment, so ...
2
votes
1answer
634 views

Can we put the mathematics of paradoxes in visual art into perspective?

(Pun definitely intended.) Dear MSE-Community, If I were to choose one artist that has made interesting works of art not only because of their beauty but also because of their connections to ...
13
votes
3answers
311 views

What can be gleaned from looking at a domain-colored graph of a complex function?

Functions from $\mathbb{C} \rightarrow \mathbb{C}$ are hard to visualize because of their 4-dimensional nature. One nice way of looking at them is by what's called domain coloring. An example from the ...
11
votes
6answers
552 views

Visualizations of some of the abstractions of algebraic geometry

Where, or do there exist, good visualizations of sheaves, stalks, stacks, and/or schemes? I'm a better visual thinker than I am a symbolic thinker, and it would be easier for me to follow some of the ...
9
votes
4answers
3k views

Intuitive Way To Understand Principal Component Analysis

I know that this is meant to explain variance butthe description on Wikpiedia stinks and it is not clear how you can explain variance using this technique Can anyone explain it in a simple way?