Linked Questions

512
votes
37answers
117k views

What are the most common pitfalls awaiting new users?

As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
31
votes
3answers
2k views

Is there a "precedence table" for the canonical Sort ordering?

This answer in which I wrote about the Operator Precedence Table was unexpectedly popular. That got me thinking about similar things, and I am wondering: Does an "ordering table" exist for the ...
18
votes
1answer
26k views

Table - find index of the maximum element [duplicate]

Let's suppose that I have table t = {1.23, 3.4, 10, 34, 1.78, 0.98, 12.56}. To take the biggest element I can use Max[t] ...
18
votes
5answers
6k views

Define a mathematical set

I have a terribly short question: Is there a way to define a pure mathematical set? I tried a bit of googling, but the word "set" has two meanings and the other one (as in setting) as by far more ...
16
votes
7answers
1k views

Find second largest elements in list

Given a list: lis = {37.21, 37.21, 37.2, 44, 44, 44, 101, 101} What is a simple way to extract the second largest elements? ...
12
votes
2answers
753 views

Surprises simplifying simple polynomials

I came across some somewhat surprising behavior of Simplify today, on something very simple. Let's take two cubic polynomials that we know have the same value: <...
11
votes
2answers
467 views

SortBy misbehaving?

It maybe a stupid thing in the end but I'm stuck a couple of hours now. I have a list of 2 points on the plane and I want to get the one with the biggest second coordinate. I thought I knew how ...
7
votes
2answers
549 views

Finding the two pairs in a list of pairs that minimize and maximize a given function

I need to declare a list of ordered pairs, and with it I need to declare a function of two variables, say x and y, and print ...
4
votes
2answers
178 views

Problems with MinimalBy, MaximalBy, SortBy [duplicate]

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4
votes
2answers
1k views

ordering of functional eigenvalues

Is there any order to the symbolic eigenvalues of a matrix returned by the command Eigenvalues[...]? While numerical eigenvalues are listed in descending order (i....
2
votes
1answer
124 views

Sort bug in Mathematica 10? [duplicate]

When I input Sort[{-Sqrt[3],0}] I get {0,-Sqrt[3]} This can't be right, can it?
2
votes
1answer
52 views

Ordering is not able to sort eigenvalues correctly! [closed]

I have a matrix as below one: ...
1
vote
1answer
216 views

Sort a list in a descending order

Say we have a list: {{1/2, -(Sqrt[3]/2)}, {1, 0}, {1/2, Sqrt[3]/2}, {-(1/2), Sqrt[3]/2}, {-1, 0}, {-(1/2), -(Sqrt[3]/2)}} now we want to sort that list by ...
1
vote
1answer
152 views

Sort does not sort {0, -Pi/2} [duplicate]

Why is this list returned unchanged by Sort? Sort[{0,-Pi/2}] {0,-Pi/2} While this list is returned reversed? Sort[{0,-1}] ...
1
vote
1answer
99 views

Sorting the eigensystem of a symbolic matrix

My symbolic matrix $A$ reads \begin{equation*} \left( \begin{array}{ccc} a \left(x^2+y^2+z^2\right) & b y z+i v x & -i v y \\ b y z-i v x & a \left(x^2+y^2+z^2\right) & b x y+i v z \\...

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