5
votes
1answer
56 views

Query or MapAt ragged associations or ignoring Missing values

Related to this question, can functions be mapped to named Keys in ragged lists of Associations? ...
8
votes
2answers
267 views

Remove versus ClearAll

What is the difference between Remove and ClearAll? I thought that "not being recognized by Mathematica", which is the effect ...
3
votes
2answers
52 views

Inflection point and curvature

Through a coordinates list and then interpolating them I got a $f[x]$. ...
0
votes
0answers
23 views

how to find the implicit Cartesian equation from calabi yau threefold?

how to find the implicit Cartesian equation from this parametric form? ...
2
votes
0answers
41 views

A bug of PrincipalValue?

Update As pointed by Emilio Pisanty, one should pay attention to EvaluationMonitor to monitor principal value integration. I update the codes, and find some more ...
0
votes
1answer
39 views

Treating the output of a plot function as a graphics object, changing the opacity

I want to treat the output of a plot (DensityPlot specifically) as a single graphics object and reduce its opacity. Something like: ...
2
votes
1answer
80 views

difference between FullSimplify and Simplify

I have a problem to dinstinguish the following two mathematica codes, the only difference is the first use FullSimplify and the second is Simplify. but the results are totally different. what is wrong,...
0
votes
0answers
21 views

how to confirm calabi yau threefold is invariant?

i have found a list of eigenspace which are complex number if i used calabi yau below and find 3d equations, it may have 3 variables need to input, does it mean that i input any 3 consecutive of ...
1
vote
2answers
113 views

How to force a replacement in an order that I want?

This is a follow-up to this question. I have a big sum, with lots of terms of the form ...
0
votes
0answers
26 views

Making a histogram with a log scale

I am really new in Mathematica. I have a data set and plot it in histogram, Now I prefer to plot it in log scale so it would be shown as a line with a specific slope. My code as related to my ...
0
votes
0answers
14 views
1
vote
1answer
28 views

Chains of approximate numeric equalities

Mathematica considers two numbers equal if "at most their last seven binary digits" differ. For example: ...
2
votes
1answer
34 views
0
votes
1answer
40 views

DSolve with coefficients and assumptions

The command below: DSolve[{s'[t] == l t, s[0] == 0}, {s[t]}, {t, 0, a}] gives the error DSolve::alliv: The function <...
1
vote
1answer
77 views

What is the source of error in the following fitting procedure in Mathematica 8.0?

I am trying to fit the following data with a user-defined model. A priori, we know that this model is supposed to be the best fit for the given data. But, I do not know why I am receiving many error ...
0
votes
2answers
50 views

Quartic function from data [on hold]

I am studying something about interpolation. I have a function that is a power x function (f[x_]:=17000 x^-1.85). From this function I got a list with coordinates ...
0
votes
0answers
229 views

How to find Multiple Maxima/Minima [duplicate]

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
1answer
138 views
1
vote
2answers
199 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 ...
1
vote
1answer
111 views

Maximising solutions of NDSolve [duplicate]

I have the following system of differential equations ...
4
votes
1answer
134 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 ...
-1
votes
1answer
190 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 ...
1
vote
1answer
94 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
1answer
98 views

Calculate area of apple from image

I want to find area of following apple I want to do something like this: define boundary region of apple apple=... then find area using only ...
1
vote
0answers
27 views

Import[] .obj data with per-vertex colors?

There's a somewhat standard way of including per-vetex color with obj files: Geometric Vertex[edit] A vertex can be specified in a line starting with the letter "v". That is followed by (x,y,z[,...
-1
votes
0answers
38 views

About function in a function

For the code below: a=1;b=2; f[c_,d_]=:Module[{e,f,g,h....},....]; (I use a=1;b=2; inside f[c_,d_]) Nminimize[f[c,d],{c,d}]; Now I am trying to do the same ...
3
votes
1answer
75 views

Progressive animation of a sequence of points

I have two pieces of code that work. The first produces a list plot: ...
1
vote
1answer
36 views

Simplifying x Conjugate[x]

I am trying to simplify a big expression containing many times terms of the form x Conjugate[x]. While this works for a single term: ...
1
vote
0answers
40 views

Line-crossing Algorithm Implementation (pt. 2)

This is a continuation of the problem I posted earlier with the line-crossing algorithm that I tried to implement in Mathematica. I took Kuba's suggestion, removing the underscore on everything ...
-2
votes
0answers
20 views

What is the differences between parametric plotting with regular plotting? [on hold]

I tried to plot using Plot[x] but sometimes people use ParametricPlot[x] to plot their graph. I just wonder, what is the differences between those two and is there any benefit of any?
3
votes
3answers
243 views

I have a 2D space and I want to make it into a torus to replicate a paper

Suppose we have a 2D grid, divided by cells, and that we assign people to each cell. Each person has 4 neighbors, one in the cell above, another in the cell below, and neighbors in the cells to the ...
0
votes
2answers
63 views

Selecting the maximum value from the results returned by NSolve

I'm trying to select the maximum value from the answers Mathematica 7.0 is getting from a simple basic NSolve algebric equation : ...
0
votes
1answer
33 views
0
votes
1answer
144 views

Trouble solving a system of 2 ODE's with NDSolve

I'm trying to solve a system of two coupled second-order ordinary differential equations using Mathematica's NDSolve. The functions of r that appear in the equations are ...
0
votes
0answers
14 views

resetting keys after using GroupBy to total

I think I saw a question like this on the site some time ago, but can't find it. I'm using GroupBy on a list of Associations to get some sums. I need to reset the keys after the GroupBy operation. ...
3
votes
3answers
118 views

Rewriting symbol context?

I have some code that uses a list of replacement rules to inject values (physical constants for different materials) into a more complicated expression. This is convenient since I can tweak the values ...
2
votes
2answers
75 views

Henon Map Fixed Points Plot versus Iterations and Plot of the Map

For the Henon Map: $$ x_{n+1}=y_n+1-αx_n^2, \quad y_{n+1}=β x_n$$ I would like to discover period doubling bifurcations by varying the parameter $α$ and plotting $x_n,y_n$ versus the iterations $n$ of ...
1
vote
1answer
32 views

Do double vertical bars in ConditionalExpression mean 'or'? [on hold]

I have a very simple interpretation question. I think that double vertical bars in a ConditionalExpression given by Mathematica as the result of an integration must mean 'or', but I am hoping to ...
7
votes
3answers
109 views

How can I draw ternary plot by these data?

I have these data and want to draw similar fifures in mathematica. any one can help me? ...
20
votes
1answer
615 views
+50

How to numerically solve a 1-d time-independent Schrödinger equation?

The point is to solve the eigensystem of the given Hamiltonian. I tried ParametricNDSolve combined with FindRoot to search for ...
0
votes
0answers
31 views

How to do abstract matrix operation?

In this simple example, I have 2 lists, each of which contains 3 matrices。 $J$ here is also a matrix with the same dimension. What I want is $aJc+bJ(b+c)$, but if I use dot product, the result is as ...
5
votes
1answer
74 views

TreeForm outputs different results for the same imputs but why?

First of all, please look at the below inputs and outputs: ...
1
vote
1answer
19 views

Size of headings for a table with graphs

I want to change the size of the heading of a table that includes graphs and am having no luck. The command I am currently using is ...
0
votes
1answer
28 views

Graphics3D plot of group of Vectors

I am trying to overlap 2 different Coordinate Systems (C1,C2). I want it to be visually pleasing but it is increasing the length of code I tried ...
1
vote
0answers
34 views

Reinstalling Mathematica pro on the SAME computer [on hold]

I am currently wiping my ENTIRE hardrive and reinstalling Windows on my (currently very slow) laptop. However, I don't want to lose my expensive version of Mathematica, and it looks like Wolfram is ...
9
votes
3answers
583 views

Interdependent controls in Manipulate [duplicate]

Possible Duplicate: How to create interrelated sliders? locking a value when manipulating variables I need to create a Manipulate with two control ...
1
vote
1answer
41 views

BSplineFunction defies numerical solution

I am trying to find an intersection between a straight line and a BSpline. The lines: ...
0
votes
0answers
85 views

How to compute this integration? [closed]

I would like to compute the following integral: Where: a and k are reals, with the assumptions: 0 < a, and 0 > k > -4. y and p are reals too. I tried to write it as ...

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