# All Questions

60,055 questions
29 views

### How to remove the given columns and strings?

Consider a data having the form data={{P,4,3,2},{V,7,8,9,55},{P,19,3,4},{V,48,6,1,55}} How to remove all rows with V and then to remove the first column, i.e., ...
27 views

### Warning: Reduce was unable to prove that the solution set found is complete

I am trying to solve the below equation, but there is a warning " Warning: Reduce was unable to prove that the solution set found is complete" . Could somebody please introduce a method for ...
16 views

### Indeterminate values in a MultivariateTDistribution

I'm running a simulation and the following error message shows up: ...
320 views

### Is there a way to convert Wolfram Language expression to string?

Is there a way to convert a Wolfram Language expression / code into a string expression? For example, Convert the following including its indentations (very important), ...
38 views

### Why is this iterative process with matrix calculation so slow?

I am trying something similar to the following code with Ntime as large as 100 or so. Now it's very slow as shown by the Ntime=3 ...
70 views

### Plotting waves intensities as colors

I have three wavelengths. Each of them has a different colour. I want to plot the resulting wave with colour that corresponds to the mixture of these colour intensities at every point. I tried this ...
66 views

### Maximize and FindMaximum drive me crazy

I have to run a numerical study. As part of it I have to solve: ...
194 views

### How to create a button that adds InputFields when clicked?

I would like to create a button 'ADD' that creates a new InputField each time the user clicks it. I have tried something like this so far: ...
32 views

### Solve an equation for a specific unknown? [on hold]

I have this equation: ...
49 views

### How to plot Intensity of SmoothKernelDistribution?

For example, we have a list of values data = RandomVariate[NormalDistribution[], 10^3]; then SmoothHistogram[data] By ...
68 views

### How to speed up FindRoot?

How can I speed up my FindRoot time, for the below code? It takes 25 seconds on my machine to find one single root for a set of $g$, $mx$, $m\psi$ values, I need to ...
42 views

### Closed form solutions to functions involving Erfc

Is there a better way to get a closed form solution in terms of sigma? I've already attempted a significant amount of simplification up to this point and am unsure ...
136 views

### Combining list in a Cartesian product format with addition operation?

I have two list to begin with. list1 = {1, 2, 3}; list2 = {10, 20, 30, 40}; I want to obtain the following output (order unimportant): ...
37 views

### How can I use options for a ParametricPlot3D?

Using this command I can plot three different curves using ParametricPlot3D ParametricPlot3D[{{t x, Sin[t x], 0}, {0 , Sin[t x], t x }, {t x ,Sin[t x], t x }}, {t, 0, Pi}, {x, 0, 4}] However, my ...
56 views

### TeXForm errors “TeXForm ofTemplateSlotSequence[1, ] is not supported” and “TeXForm of 0.78492 +1.30714 I is not supported” in 12

Reported to WRI. CASE:4250134 Update: Thanks for the smaller example by Chip Hurst in comment, it seems it comes down to this simpler example ...
25 views

### Turning off or modifying the displayed Code Assist value for a specific input alias

Short Version: How do I turn off (or specify a simple replacement for) Code Assist predictive-interface for a specific input alias? Longer Version: Using the Notation package I have put together a ...
34 views

### Webassign Calculus 2 problems help [on hold]

Find the equations tangent to x = 6t^2 +4 and 4t^3 +4. F[t_] := 6t^ 2 + 4; G[t_] := 4^t3 + 4; H[t_]:=G'[t]/F'[t]; H[t]= 0 t-> -1, t -> 1 (use point slope formula y-y1=m(x+x1)) I get y = (x-10)+8
39 views

### Writing a script that exports results depending on user input

Is there a way to tell Export to hold its arguments and just Export. I tried to use ...
430 views

### Plotting a Maclaurin series

Can anyone plot the degree-8 Maclaurin polynomial for the function $(x+1)/((x^2)-9)$ and function $(x+1)/((x^2)-9)$ on the same plot. Please help, I've tried everything I could think of.
750 views

### Noise in Eigenvalues plot

I am trying to Plot Eigenvalues of a Hamiltonian, but I am getting noisy plot, which is incorrect. Here is the code. ...
109 views

### What rules determine displaying implicit '×' between products of functions in Mathematica 12?

I noticed if I type sin[x] cos[x] and hit Shift+Return to run it in the Mathematica 12 frontend notebook, a grey '×' character is printed between the functions. ...
54 views

### Mathematica cannot solve quadratics? [on hold]

I just downloaded Mathematica for Students for Sites (Mathematica 12, on Linux), and it appears to be unable to solve quadratic equations. Solve[x^2 == 36, x] ...
42 views

### Exchanging X and Y axes

I was wondering if I could have help with the rotation of the axis of my plot. ...
202 views

### Vertical ranges of Column in ListLinePlot in 12

Version 12 includes a new Layout->Column option for ListPlot which aligns multiple plots so they share a single horizontal axis. It seemed really useful at first....
25 views

### Defining an expression to insert into NDSolve

Consider the follwoing Code: ...
150 views

### NIntegrate on a solution of a matrix ODE

I've seen similar questions on this site but somehow the solutions there didn't manage to solve my specific problem. I have a function mat1 that takes a square $n \times n$ matrix G, and some final ...
44 views

### Solve a constrained four-dimensional integration problem for a “magic simplex” probability

Equation (7) in the 2012 paper, "Complementarity Reveals Bound Entanglement of Two Twisted Photons" of B. C. Hiesmayr and W. Löffler for a state $\rho_d$ in the "magic simplex" of Bell states \begin{...
32 views
+50

### Plot BV functions with singular derivatives in multiple space dimension

In 1-dimensional setting, two key examples of $BV$ functions (of bounded variation) $u: \mathbb R \to \mathbb R$ are the Heaviside function, whose derivative is the Dirac delta concentrated at $0$. It ...
38 views

### Exploring an equation's solution space with Manipulate

I have the following simple Manipulate code that I use for solving an equation in two stages. In the first stage I identify the initial values ...
71 views

### Is it possible to find the Rössler attractor using only a set of Lyapunov exponents?

Is it possible to use a set of Lyapunov exponents to determine the orbits of the Rössler system? If so, could how would I go about plotting them? EG. Known Unknown
716 views

### How to evaluate this function?

I’m trying to evaluate y[t] = InverseFunction[ NIntegrate[Sqrt[2]/( -8+Exp[y]+2Exp[-y]), {y,0,t}]] Some of the problems I’m facing, is that i’d like to get the ...
53 views

### FrameTicks in DateListPlot doesn't support “All” in Mathematica 12

In mathematica 12, DateListPlot[{1, 1, 2, 3, 5, 8, 11}, {2000, 8}, FrameTicks -> All] gives And the error message is A ticks specification in the value ...
35 views

### Solving an equation with 3 free parameters in a way that satisfies a condition

I have an equation in terms of $q$, $c_2$, $c_3$ and $r$. I just know that $q$ and $r$ are positive (there are no restrictions on $c_2$ and $c_3$). ...
170 views

### Version 12 Documentation bugs [on hold]

Not a question but would like to ask if anyone else has installed version 12 of the wolfram language and found links missing or pointing in the wrong direction on the guide pages. For example, on <...
49 views

### Returning a string from a piecewise function

I need to define a function that behaves as a piecewise function, but will return a string instead of a value. Part of the function that I have written is provided below. The full function continues ...
36 views

I'm working with Maximize and it does not generate any result but simply reproduces the same code. My object function is rather complex which is: $0.18 k-0.36 + \... 1answer 101 views ### How to solve this nonlinear second- order ODE? Any help how in Mathematica to solve y’’[t]+1/2 y’[t]^2 - 1/2 Exp[y[t]]+2 ==0 To get y(t), with no knowledge by any initial conditions for y(t) or y’(t) ? Edit: ... 0answers 33 views ### Differential transform method to solve differential equations [on hold] I am new user to Mathematica. Can anyone please help me to write a mathematica code to solve Ricatti equation. 2answers 68 views ### Removing parenthesis from a list Say I have a list ... 1answer 37 views ### Select two of three in a triplet list {{x1,y1,z1}, {x2,y2,z2}} [on hold] I have a list of triplets {{x1,y1,z1}, {x2,y2,z2}.....} and would like to plot$x$vs.$y$, then$x$vs.$z$. ListLinePlot will ... 1answer 44 views ### Plotting a graph of a function and part of it I am doing a numerical experiment for solving some differential equation. In some part I need to plot a graph of the exact and approximated solutions. However, they are very closed to each other and ... 1answer 91 views ### Why DSolve can’t give a solution for an exponential function? How to solve a nonlinear Second-Order ODEs like the following in Mathematica?$ y’’(t) + y’(t) - e^{y(t)} = 0 $I tried DSolve, but it dose not work: ... 2answers 48 views ### Apply matrixform to limited rows and columns of a matrix I have a big matrix, you can say 1000*1000 whose elements are functions of several parameters such as a, b. I wish to see just a ... 3answers 96 views ### How to change the tick of the color bar legend to black? Is there any option that allows one to change the ticks and borders of the bar legend in a density plot to black? 4answers 60 views ### Adding a number to the 2nd element of each pair in a list of pairs I can't figure out how to add a constant value to a list. The list to which the data variable is bound was imported from a CSV file with 2 columns. For example, <... 0answers 50 views ### Plotting a paraboloid and a plane I am trying to visualize the intersection of a paraboloid and and a plane. My paraboloid is of the form $$f(x) = \frac{1}{2} x^\top A x - b^\top x$$ where$x$is a vector and$A$is the pd matrix$A =... 2answers 38 views ### How to align text to the left when inside a graphic? I am using Show to display a set of lines. Now I am trying to label them inside the plot with P=0/0.25/0.5/0.75/0.9. However, as you can see from the attached plot, the text seems to center around 0.2,... 1answer 20 views ### Listing Permutations of Two Elements LetS_{k}^{(n)}$be the set of all possible lists of length$n$containing exactly$k$-times$\sigma$and$(n-k)$-times$\Delta$. For instance,$S_{2}^{(4)}=\bigl\{\{\sigma,\sigma,\Delta,\Delta\},\{\...
given matrices A = {{3, 10, 10, 5.}, {4, 10, 10, 6.}, {5, 10, 10, 7.}} B = {{6, 10, 10, 5.}, {7, 10, 10, 6.}, {8, 10, 10, 7.}} how can i get a matrix which ...