Questions on finding the largest value of a set, extreme values of an expression, or on Mathematica functionality for maxima testing.

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5
votes
2answers
239 views

Max of imported numerical data will not work

I loaded a list with 400,000 values from a file. The list was loaded correctly as I can get it's length (by Length[]) and I can also plot it. Why can't I get the Max or Min of this list though? When ...
1
vote
1answer
69 views

How to find a maximum value in a rotated parametric plot?

Let me just give you a bunch of tables to reproduce the problem. Here they are ...
5
votes
2answers
265 views

Finding minimum and maximum of implicit functions

The equations of the system are ...
1
vote
2answers
74 views

Ploting horizontal lines in a ListLinePlot?

Hello i have made a graph with a oscillating behavior but i need to highlight the maximum value of the oscillation because i will use that value like a threshold and I need to put a horizontal line in ...
2
votes
2answers
189 views

Put markers in the maximum values in a Plot

I have made my graph of a list of data with the following code: ListLinePlot[data, PlotMarkers -> {Automatic, 10}] So this way I can see some markers in the ...
1
vote
2answers
66 views

Add elements to the maximum values of a list

Hi i have a list of n elements and i want to know the 30 maxim values of list without changing his order. And suppose that i have a second list with n elements and i want to add this elements to the ...
2
votes
2answers
85 views

MaximalBy with infinity

I don't understand why this doesn't work: MinimalBy[{{1, -Infinity}, {2, 3}}, Last] it outputs {2,3}!
3
votes
2answers
88 views

Retaining relative sizes of local maxima using MaxDetect[List]

I would like to be able to find the position of the two greatest local maxima in a list. For the example: list={1,2,3,4,2,1,2,6,5,4,3,2,} I would like to return ...
3
votes
1answer
65 views

Recognising degenerate maxima in a matrix

Say I have the following matrix $\left( \begin{array}{cccccc} 1. & 0 & 0 & 0 & 0 & 0 \\ 0 & 0.707107 & 0 & 0 & 0 & 0.707107 \\ 0 & 0.707107 & 0 ...
-2
votes
1answer
148 views
0
votes
0answers
70 views

Solving Lagrangian (4 vars to solve for)

I'm a bit new to Mathematica, but here's what I've got: ...
4
votes
1answer
260 views

How to draw a tropical surface?

By definition, a tropical surface in $\mathbb R^3$ is the set of points $(x,y,z)$ where the maximum $f=\max(f_1,f_2,\dots,f_n)$ is attained at least twice, here $f_i$ stand for some linear functions ...
2
votes
2answers
122 views

Only one root at specific interval

I need a help to find k here: $f(x)=-k^x + x^2$ It is not too simple. I have interest to find the single value of "k" where, inside interval {x,2,3}, the function have only one value to x when f(x) ...
0
votes
1answer
112 views

Finding Coordinates of a Peak on a Pot - Problem with Position[…]

I have plotted a graph from a CSV file which consists of two columns of data Time and Intensity. I simply want to find the time where the intensity is largest. ...
0
votes
0answers
188 views

How to find Multiple Maxima/Minima

I am trying to solve a problem that requires finding multiple maxima of a numerical function. So the function generates some numbers that are coming out of an experiment. I tried using NMaximize or ...
1
vote
2answers
102 views

Find maximum of 'y' coordinates from a list of duplicate 'x' coordinates

I have a multidimensional-variable list, suppose for example {{x1,y1},{x2,y2}..}. I have duplicate values for the 'x' coordinates and I need to find for the duplicate 'x' elements the corresponding ...
2
votes
1answer
67 views

ArgMax and result readability

Trying to maximize a two-variable expression and to get variables' values at maximum points: ...
1
vote
2answers
99 views

Performance in calculating maximum-likelihood- based estimates

My probability density function is a complicated one for which numerical estimation is necessary. Here my pdf: ...
1
vote
1answer
106 views

Why `FindMaximum` doesn't work in my example

Consider the following function ...
1
vote
2answers
132 views

Incorporating the minimum and maximum of the function in a Dynamic plot

I'm working on my project for class and it's supposed to be a graph that can take functions from the user and display it along with finding the max and min of the graph. But I just don't know how to ...
0
votes
1answer
130 views

Graphic solution lagrange multiplier (cant get one)

I need to find the maxima and minim of a function. I did analytically with no problem but now I need to show in a graphic the intersection of the functions. My function is: ...
1
vote
1answer
101 views

Maximising solutions of NDSolve [duplicate]

I have the following system of differential equations ...
2
votes
2answers
209 views

Maximize simple Polynom: Wrong answer

I want to maximize $poly$ under the constraints $g1,g2,g3=0$ ...
0
votes
1answer
102 views

Defining some function [closed]

Please help me with the following problem. For any function $f(u)$ I simply define function $f^*(x)$ as follows $$f^*(x)=\sup_{0\leq u\leq x}f(u)$$ How can I define $f^*$ using Mathematica code?
2
votes
4answers
365 views

How do I find the position of the maximum value in each column of a table?

Given a table of values, I know how to find find maximum values, but how do I find the position of the maximum value in each column. For example, given ...
2
votes
4answers
247 views

Problem in finding the numerical maximum

I need to find the numerical maxima of the function $$i(s)=\bigg[ \frac{\sin{50\pi (\cos s+1)}}{\sin{10\pi (\cos s+1)}} \bigg] ^2$$ Or in the mathematica input form: ...
0
votes
2answers
218 views

Maximizing a trigonometric function

This is probably a naive question, but here it goes: I know that $$r\cos a+s\cos b+t\cos c \leq \frac{rs}{2t}+\frac{rt}{2s}+\frac{ts}{2r},$$ subject to the conditions $a+b+c=\pi$ and $r,s,t$ are ...
4
votes
1answer
128 views

How can I find the greatest of this expression?

I want to find the greatest of the expression $$P=a \sqrt{12-b}+\sqrt{b\left(12+a^2\right)}+66\sqrt{a^2+b+3}-\left(a^2+b\right)^2$$ with $a >0$, $0<b\leq 12$. I tried ...
10
votes
3answers
433 views

Maximize violating constraints

I have Maximize[{(h*10)/(300*(100 - (l^.5 + d^.4 + H^.6))), (l + d + H + h) == 669, l > 0, d > 0, H > 0, h > 0}, {h, l, d, H}] I believe ...
15
votes
2answers
2k views

Find maximum value of interpolation function - obviously wrong result

Minimizing and maximizing interpolation function has already been asked and answered, see here for example. Yet, I observe a strange behaviour. Well, I can understand that the wrong guess of ...
1
vote
3answers
412 views

Finding maximum value with position from Table of values

I have this table of values, how do I find the maximum value? i.e. find $z_{max}(x,y)$ ...
-1
votes
1answer
165 views

Finding the maximum of a gradient vector

Im trying to find the maximum of my gradient vector G[x,y], I've tried several options including FindMaximumValue, FindMaximum etc. but i couldn't find it. The full function is shown below, any help ...
0
votes
3answers
234 views

Why does Maximize return a wrong answer?

I want to find the maximum of the following function, but get a wrong result. What am I doing wrong? ...
0
votes
2answers
366 views

How to find a max point from discrete data of function?

I have a lot of points like $\{\{x_1,y_1,z_1\},\{x_2,y_2,z_2\},...,\{x_n,y_n,z_n\}\}$ which obtained by a function $z=f[x,y]$, and I want to find the max point of $z$, say $z_i$, and return the point ...
2
votes
1answer
77 views

Results of ArgMax as a function of a parameter with InterpolatingFunctions

I would like to obtain a function and its derivatives, where the function is defined as the solution to a maximization problem. The obvious approach ...
0
votes
0answers
120 views

How do I find where the maximum is?

I have a function given by: ...
1
vote
1answer
457 views

How to find the local maximum of a list [duplicate]

I have imported a wav sound that a = Import["sound.wav"] and we know that soundStrength = a[[1]][[1]] is a list of sound ...
1
vote
1answer
86 views

Moving the start of a graph to the right, finding maxima in an oscillator

I have the following code written to simulate a driven damped oscillator ...
3
votes
3answers
262 views

FindRoot constrained to maximum

I am using FindRoot to find the local maximum op some function, by examining where its derivative is zero. However, keeping the starting value the same, sometimes ...
2
votes
1answer
281 views

Finding the optimal teams ranking based on the table of match results

My original question was this: So my task is to score all the possible rankings of the 14 SEC football teams and find the best one, using who won in head-to-head games as the sole criterion ...
0
votes
0answers
184 views

Maximum of NDSolve output. Problem with interpolating function

I solve a NonLinear PDE and get a solution (which for other reasons I put into a vector): SolVec1[1][[2]][x,t], where x and t are the indipendent variables. Now, I would like to get a distribution ...
19
votes
5answers
2k views

Moving maximum function?

How can I construct a moving maximum function? For example, if I have a list of 12 values: { 5, 6, 9, 3, 2, 6, 7, 8, 1, 1, 4, 7 } and I want to maximize over 3 ...