# All Questions

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? ...
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 ...
52 views

### Inflection point and curvature

Through a coordinates list and then interpolating them I got a $f[x]$. ...
42 views

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23 views

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

how to find the implicit Cartesian equation from this parametric form? ...
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 ...
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: ...
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,...
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 ...
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 ...
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 ...
14 views

### Table gives error “Expresion i cannot be used as part specification”

I am defining the following command ...
28 views

### Chains of approximate numeric equalities

Mathematica considers two numbers equal if "at most their last seven binary digits" differ. For example: ...
34 views

### Is it possible to change the color of a Control option when selected?

For this Control inside Manipulate (using Setter or ...
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 <...
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 ...
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 ...
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 ...
138 views

### Why FindMaximum doesn't work in my example

Consider the following function ...
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 ...
111 views

### Maximising solutions of NDSolve [duplicate]

I have the following system of differential equations ...
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 ...
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 ...
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 ...
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 ...
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 A vertex can be specified in a line starting with the letter "v". That is followed by (x,y,z[,...
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 ...
75 views

### Progressive animation of a sequence of points

I have two pieces of code that work. The first produces a list plot: ...
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: ...
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 ...
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?
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 ...
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 : ...
33 views

### How to make two numbers coincide

For the below plot: ...
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 ...
20 views

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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. ...
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 ...
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 ...
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 ...
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? ...
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 ...
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 ...
74 views

### TreeForm outputs different results for the same imputs but why?

First of all, please look at the below inputs and outputs: ...
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 ...
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 ...
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 ...
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 ...