# All Questions

4 views

### Replace every power of $e^{i\theta}$ with $z$

If I have the expression $\frac{1}{13-\frac{5}{2} i \left(e^{-i \theta }-e^{i \theta }\right)}$ and I want to replace each $e^{i\theta}$ with $z$, so that the result is ...
21 views

### Plotting function described by other functions!

I want to plot and manipulate my VS function which comes from the other functions above it. So, what should I use in order to draw my function considering that it is described by other functions. I ...
21 views

### Check if interpolated function passes through a specified region

Is there an efficient way to check if a curve that was obtained as an Interpolating Function (from solving differential equations numerically) passes through a given region? I am solving for two ...
80 views

### Replace For with If in Mathematica way

I have this code: ...
9 views

### Palette Sizing Options

I am writing a palette to work with units on Mathematica 9, using just PasteButtons, and have a Button map that works as I want it to, but the formatting of the palette itself is giving me issues. I ...
52 views

### ListPlot with colors

Let's create some sample data n = 100; d00 = Table[{RandomReal[{-1, 1}], RandomReal[{-4, 4}], RandomReal[{-1, 1}]}, {i, 1, n}]; Now I want the following: create ...
41 views

### Solving a big number of non linear equations

I have three trapezoids. The first sharing its upper side (I will call b_{i+1} in the code) with the second, the third sharing its lower side with the upper side of the second. All shared sides are ...
41 views

### How to make Mathematica solve an equation in an analytic class?

Here is my small code: ...
30 views

### ColorBars or PlotLegends for ElementMeshSurfacePlot3D

I want to produce a colorbar legend to the output from ElementMeshSurfacePlot3D (Mathematica 10). The pde was solved using NDSolveValue (FEM pdesolution is the resulting interpolating function) over a ...
24 views

### How to speed up Solve command in Mathematica 8.0?

I have two complicated mathematical functions $f(s)$ and $g(M)$ that are complicated functions of $s$ and $M$ respectively. I would like to solve the equation $f(s)=g(M)$ in order to plot $s$ vs. $M$. ...
28 views

### Export list entries under a certain condition without using loops

I have a big list that contains many 3D- chains (set of points) and for each of them a polynomial. So the structure of my list is for example ...
56 views

### Distinguish hashtag # operator when using multiple functions

I would like to do this list = Append[list[[#]],Map[list2[[1, #]] & , list[[#, 4]], {2}]] & /@ Range[Length[list]]; But I would like to substitute ...
34 views

### How to find a root for an integral equation?

I try to find numerical solution $E_f$ to satisfy the following equation: ...
47 views

### Trying to create a model and manipulate plot

I have been trying to learn mathematica to implement financial models in it. However, I am still very inexperienced in this :) Currently, I have what is presented below but I can't figure out why it ...
231 views

### How to measure the slit size from given image using mathematica?

I want to measure the size of the optical slit from the microscope image. Here is the image. The dimension of image data is {1300,1030} and the real pixel size is 6.7 micron. But the problem is ...
32 views

### NDSolve with coupled ODE's and unknown singularities

I have two coupled ODEs that I am trying to solve numerically. It appears that there is a singularity in the solution to the equations which I am unsure how to get past. Both functions $\alpha$ and ...
34 views

### Translate Tick Marks

The code below creates a StreamPlot for a nonlinear system of first-order ODEs: $\dot{x}=y,\dot{y}=x+\tfrac{1}{4}x^{2}$ I have created a simple zoom slider that expands the region about the critical ...
34 views

### A table of FourierSeries going wrong

I have a function $$F(t)=\left\{\begin{matrix} F_0\frac{2t}{T}&,0\leq t \leq T/2 \\ -F_0& ,T/2\leq t \leq T \end{matrix}\right.$$ that should look something like this ...
64 views

### Implicitly inverting a function from numerical solution

I have the following piecewise continuous function: ...
55 views

### Integral invoving product of Whittaker functions

I'm trying to evaluate the integral $$\int W_{0,a}(x)\,W_{1,b}(x)\,\frac{dx}{x},$$ where $W$ denotes the Whittaker $W$ function, and $a,b\in[0,1/2]$. Using the Whittaker differential equations that ...
21 views

### How do you collect trigonometric functions in a polynomial?

I have an expression that has various forms of Sin and Cos and I want to collect them specifically so that I can make substitutions. As you can see I cannot figure out how to separate i Cos[theta] ...
12 views

### Help in finding Probability distribution table [on hold]

A discrete random variable X has probability function given by f(x)= k x^3 for x=1,2,3,4. Then find a. Value of k b. Probability at x=2 c. Mean of X d. Variance of X e. Probability distribution ...
112 views

### How to obtain this expression in terms of real functions

I know that this expression (2 (ArcCot[E^(-((I ϕ)/2)) r] + ArcCot[E^((I ϕ)/2) r]))/π is real, because is the sum of a real series, in particular: ...
34 views

### Plotting a data of protein diffusion trajectory

I have a set of data points of protein diffusion in x-y plane. They are sequential in time i.e, recorded at regular intervals of 20ms. Now, I need to plot a line plot in 2 dimensions, which connects ...
32 views

### Plot values of parameter

Noob-alert: I have a Mathematica notebook with a lot of engineering formulas and several inputs. I want to plot one of these formulas as a function of one of the inputs. The formula in question is ...
14 views

### how to calculate point after rotation [migrated]

I have basic square with width 36 (red) I'm rotating square by XYZ degrees ... in example there is 45 degrees black square is rotated by point 0,0 green square is rotated by center of sqare 18,18 ...
33 views

### Importing data from a MATLAB file to MATHEMATICA

I have been trying to import some matrices from MATLAB to MATHEMATICA. The matrices are the output after I run the MATLAB file. I had saved that file in .MAT format and trying to import it in ...
64 views

### How to Combine 3D graphics

I'm trying to put this solid S1 = RegionPlot3D[z - 50 <= -2 x^2 - 2 y^2, {x, -5, 5}, {y, -5, 5}, {z, 0, 50}] on top of this one ...
26 views

### How we get the ANOVA and Parameter Tables in Mathematica of the Ridge regression like the linear model

Dear how we find the ANOVA and Parameter Tables of the ridge regression like the linear model on randomly generated independent and dependent variables.
19 views

This is a followup of "How to check for Mathematica’s definition of XY?, a question by uli on how to access the definition of a built-in symbol. That question focused on ...
27 views

### How to prove it? [on hold]

Under $P$, the random variable X has a double exponential distribution with positive constants, $r_1$,$r_2$,$p$,$q$ such that $p+q=1$, with the probability distribution function given as: ...
59 views

### Symbolic calculation on roots of polynomial

Given a polynomial like $x^3 + a_2 x^2 + a_1 x + a_0$ with roots $r_i$, I would like to symbolically compute the coefficients of a polynomial whose roots are $r_i^3 + r_i + 1$. How can I do this in ...
20 views

### Histogram plot for fixed class interval

Age Size of Kidney 0-20 8.5 20-40 9.2 40-60 10.4 60-80 9.3 80-100 8.9 The above data gives the average size of the kidney for the people of age ...
37 views

### Function inversion

I have an expression of this kind ...
39 views

### I would like to be able to get this integral evaluation to show up in terms of variables

this is very much a beginner question; I was hoping that someone may be able to take a look at this code and tell me why it outputs all of these crazy numbers instead of just the variables specified ...
47 views

564 views

### Difference between = and Ctrl + =

What is a difference between $\textbf{=}$, and Ctrl + $\textbf{=}$? For instance there are some examples, but result is same. and
54 views

### How to avoid tranfer the array as a parameter

I have following array: data = {x^2, 2*x^2, x^3}; And I must send it to the following function: ...
70 views

### Can I hold a condition in NMaximize/NMinimize?

I'd like to use NMaximize/NMinimize with the condition ...
114 views

### Can I put Association brackets <| … |> in an autocompletion template?

I have a function f which takes as one of its arguments an Association object, and I would like to produce a nice usage message ...
71 views

### Rudimentary/basic simplifications of expressions not carried out--very puzzling!

Here's the raw input cell form--trying to follow MarcoB's suggestion--of the "offending" expression "g2": g2 = Piecewise[ {{(1/(1435*ra))(2(-1 + ra)^6*(11*ra^3*(-896*(201 + 16*rb) + .10*(368699 ...
50 views

### Sampling a Dirichlet Distribution efficiently

I'm sampling a DirichletDistribution like so: ...
36 views

### Crash after long GroebnerBasis calculation

I am running a long computation of a GröbnerBasis and after some hours the kernel crashes. The memory usage increases enormous, and it crashes, when it reaches somewhat 4 GB RES, however it is ...
Cauchy principal value of the following integration gives nothing in Mathematica. $\int\limits_{-\infty}^\infty\frac{\text{dx}}{x-2}$ I tried some hand calculation which is ...